JIRA: https://issues.redhat.com/browse/RHEL-27740
Tested: by me
commit 1bfb7684db1233d9e3f3f26fbbc0c58d40ff65e7
Author: Baolin Wang <baolin.wang@linux.alibaba.com>
Date: Tue Jan 10 21:36:20 2023 +0800
mm: compaction: count the migration scanned pages events for proactive compaction
The proactive compaction will reuse per-node kcompactd threads, so we
should also count the KCOMPACTD_MIGRATE_SCANNED and KCOMPACTD_FREE_SCANNED
events for proactive compaction.
Link: https://lkml.kernel.org/r/b7f1ece1adc17defa47e3667b5f9fd61f496517a.1673342761.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Aristeu Rozanski <arozansk@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-27740
Tested: by me
commit 753ec50d976c28b08266dec3110905b377464eb1
Author: Baolin Wang <baolin.wang@linux.alibaba.com>
Date: Tue Jan 10 21:36:19 2023 +0800
mm: compaction: move list validation into compact_zone()
Move the cc.freepages and cc.migratepages list validation into compact_zone()
to remove some duplicate code.
Link: https://lkml.kernel.org/r/15cf54f7d762e87b04ac3cc74536f7d1ebbcd8cd.1673342761.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Aristeu Rozanski <arozansk@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-27740
Tested: by me
commit c6835e8d86bcd8313347e097da140057772307c0
Author: Baolin Wang <baolin.wang@linux.alibaba.com>
Date: Tue Jan 10 21:36:18 2023 +0800
mm: compaction: remove redundant VM_BUG_ON() in compact_zone()
Patch series "Some small improvements for compaction".
When I did some compaction testing, I found some small room for
improvement as well as some code cleanups.
This patch (of 5):
The compaction_suitable() will never return values other than
COMPACT_SUCCESS, COMPACT_SKIPPED and COMPACT_CONTINUE, so after validation
of COMPACT_SUCCESS and COMPACT_SKIPPED, we will never hit other unexpected
case. Thus remove the redundant VM_BUG_ON() validation for the return
values of compaction_suitable().
Link: https://lkml.kernel.org/r/cover.1673342761.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/740a2396d9b98154dba76e326cba5e798b640ead.1673342761.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Aristeu Rozanski <arozansk@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-27740
Tested: by me
commit 61d3d5108eb621d2a097c41f6cc83bf63b1b6c03
Author: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri Jan 6 14:59:00 2023 +0100
mm: remove PageMovable export
The only in-kernel users that need PageMovable() to be exported are z3fold
and zsmalloc and they are only using it for dubious debugging
functionality. So remove those usages and the export so that no driver
code accidentally thinks that they are allowed to use this symbol.
Link: https://lkml.kernel.org/r/20230106135900.3763622-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Aristeu Rozanski <arozansk@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-14702
Upstream-status: https://git.kernel.org/pub/scm/virt/kvm/kvm.git
Add an "unmovable" flag for mappings that cannot be migrated under any
circumstance. KVM will use the flag for its upcoming GUEST_MEMFD support,
which will not support compaction/migration, at least not in the
foreseeable future.
Test AS_UNMOVABLE under folio lock as already done for the async
compaction/dirty folio case, as the mapping can be removed by truncation
while compaction is running. To avoid having to lock every folio with a
mapping, assume/require that unmovable mappings are also unevictable, and
have mapping_set_unmovable() also set AS_UNEVICTABLE.
Cc: Matthew Wilcox <willy@infradead.org>
Co-developed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20231027182217.3615211-15-seanjc@google.com>
(cherry picked from commit 0003e2a414687fff6a75250d381e4abf345d663f)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[RHEL-only: use page functions instead of folio]
JIRA: https://issues.redhat.com/browse/RHEL-10059
MAX_ORDER currently defined as number of orders page allocator supports:
user can ask buddy allocator for page order between 0 and MAX_ORDER-1.
This definition is counter-intuitive and lead to number of bugs all over
the kernel.
Change the definition of MAX_ORDER to be inclusive: the range of orders
user can ask from buddy allocator is 0..MAX_ORDER now.
[kirill@shutemov.name: fix min() warning]
Link: https://lkml.kernel.org/r/20230315153800.32wib3n5rickolvh@box
[akpm@linux-foundation.org: fix another min_t warning]
[kirill@shutemov.name: fixups per Zi Yan]
Link: https://lkml.kernel.org/r/20230316232144.b7ic4cif4kjiabws@box.shutemov.name
[akpm@linux-foundation.org: fix underlining in docs]
Link: https://lore.kernel.org/oe-kbuild-all/202303191025.VRCTk6mP-lkp@intel.com/
Link: https://lkml.kernel.org/r/20230315113133.11326-11-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc]
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
(cherry picked from commit 23baf831a32c04f9a968812511540b1b3e648bf5)
[RHEL: Fix conflicts by changing MAX_ORDER - 1 to MAX_ORDER,
">= MAX_ORDER" to "> MAX_ORDER", etc.]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-1848
commit 493614da0d4e8d8bb37c3c558e0c01de20344cff
Author: Johannes Weiner <hannes@cmpxchg.org>
Date: Mon Jul 31 13:24:50 2023 -0400
mm: compaction: fix endless looping over same migrate block
During stress testing, the following situation was observed:
70 root 39 19 0 0 0 R 100.0 0.0 959:29.92 khugepaged
310936 root 20 0 84416 25620 512 R 99.7 1.5 642:37.22 hugealloc
Tracing shows isolate_migratepages_block() endlessly looping over the
first block in the DMA zone:
hugealloc-310936 [001] ..... 237297.415718: mm_compaction_finished: node=0 zone=DMA order=9 ret=no_suitable_page
hugealloc-310936 [001] ..... 237297.415718: mm_compaction_isolate_migratepages: range=(0x1 ~ 0x400) nr_scanned=513 nr_taken=0
hugealloc-310936 [001] ..... 237297.415718: mm_compaction_finished: node=0 zone=DMA order=9 ret=no_suitable_page
hugealloc-310936 [001] ..... 237297.415718: mm_compaction_isolate_migratepages: range=(0x1 ~ 0x400) nr_scanned=513 nr_taken=0
hugealloc-310936 [001] ..... 237297.415718: mm_compaction_finished: node=0 zone=DMA order=9 ret=no_suitable_page
hugealloc-310936 [001] ..... 237297.415718: mm_compaction_isolate_migratepages: range=(0x1 ~ 0x400) nr_scanned=513 nr_taken=0
hugealloc-310936 [001] ..... 237297.415718: mm_compaction_finished: node=0 zone=DMA order=9 ret=no_suitable_page
hugealloc-310936 [001] ..... 237297.415718: mm_compaction_isolate_migratepages: range=(0x1 ~ 0x400) nr_scanned=513 nr_taken=0
The problem is that the functions tries to test and set the skip bit once
on the block, to avoid skipping on its own skip-set, using
pageblock_aligned() on the pfn as a test. But because this is the DMA
zone which starts at pfn 1, this is never true for the first block, and
the skip bit isn't set or tested at all. As a result,
fast_find_migrateblock() returns the same pageblock over and over.
If the pfn isn't pageblock-aligned, also check if it's the start of the
zone to ensure test-and-set-exactly-once on unaligned ranges.
Thanks to Vlastimil Babka for the help in debugging this.
Link: https://lkml.kernel.org/r/20230731172450.1632195-1-hannes@cmpxchg.org
Fixes: 90ed667c03fe ("Revert "Revert "mm/compaction: fix set skip in fast_find_migrateblock""")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-1848
commit 90ed667c03fe553a41d79057740ed5df951eead0
Author: Mel Gorman <mgorman@techsingularity.net>
Date: Mon May 15 12:33:44 2023 +0100
Revert "Revert "mm/compaction: fix set skip in fast_find_migrateblock""
This reverts commit 95e7a450b819 ("Revert "mm/compaction: fix set skip in
fast_find_migrateblock"").
Commit 7efc3b726103 ("mm/compaction: fix set skip in
fast_find_migrateblock") was reverted due to bug reports about khugepaged
consuming large amounts of CPU without making progress. The underlying
bug was partially fixed by commit cfccd2e63e7e ("mm, compaction: finish
pageblocks on complete migration failure") but it only mitigated the
problem and Vlastimil Babka pointing out the same issue could
theoretically happen to kcompactd.
As pageblocks containing pages that fail to migrate should now be forcibly
rescanned to set the skip hint if skip hints are used,
fast_find_migrateblock() should no longer loop on a small subset of
pageblocks for prolonged periods of time. Revert the revert so
fast_find_migrateblock() is effective again.
Using the mmtests config workload-usemem-stress-numa-compact, the number
of unique ranges scanned was analysed for both kcompactd and !kcompactd
activity.
6.4.0-rc1-vanilla
kcompactd
7 range=(0x10d600~0x10d800)
7 range=(0x110c00~0x110e00)
7 range=(0x110e00~0x111000)
7 range=(0x111800~0x111a00)
7 range=(0x111a00~0x111c00)
!kcompactd
1 range=(0x113e00~0x114000)
1 range=(0x114000~0x114020)
1 range=(0x114400~0x114489)
1 range=(0x114489~0x1144aa)
1 range=(0x1144aa~0x114600)
6.4.0-rc1-mm-revertfastmigrate
kcompactd
17 range=(0x104200~0x104400)
17 range=(0x104400~0x104600)
17 range=(0x104600~0x104800)
17 range=(0x104800~0x104a00)
17 range=(0x104a00~0x104c00)
!kcompactd
1793 range=(0x15c200~0x15c400)
5436 range=(0x105800~0x105a00)
19826 range=(0x150a00~0x150c00)
19833 range=(0x150800~0x150a00)
19834 range=(0x11ce00~0x11d000)
6.4.0-rc1-mm-follupfastfind
kcompactd
22 range=(0x107200~0x107400)
23 range=(0x107400~0x107600)
23 range=(0x107600~0x107800)
23 range=(0x107c00~0x107e00)
23 range=(0x107e00~0x108000)
!kcompactd
3 range=(0x890240~0x890400)
5 range=(0x886e00~0x887000)
5 range=(0x88a400~0x88a600)
6 range=(0x88f800~0x88fa00)
9 range=(0x88a400~0x88a420)
Note that the vanilla kernel and the full series had some duplication of
ranges scanned but it was not severe and would be in line with compaction
resets when the skip hints are cleared. Just a revert of commit
7efc3b726103 ("mm/compaction: fix set skip in fast_find_migrateblock")
showed excessive rescans of the same ranges so the series should not
reintroduce bug 1206848.
Link: https://bugzilla.suse.com/show_bug.cgi?id=1206848
Link: https://lkml.kernel.org/r/20230515113344.6869-5-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Tested-by: Raghavendra K T <raghavendra.kt@amd.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Chuyi Zhou <zhouchuyi@bytedance.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-1848
commit 590ccea80af950685de7f72ec43831765e5c8cb1
Author: Mel Gorman <mgorman@techsingularity.net>
Date: Mon May 15 12:33:43 2023 +0100
mm: compaction: update pageblock skip when first migration candidate is not at the start
isolate_migratepages_block should mark a pageblock as skip if scanning
started on an aligned pageblock boundary but it only updates the skip flag
if the first migration candidate is also aligned. Tracing during a
compaction stress load (mmtests: workload-usemem-stress-numa-compact) that
many pageblocks are not marked skip causing excessive scanning of blocks
that had been recently checked. Update pageblock skip based on
"valid_page" which is set if scanning started on a pageblock boundary.
[mgorman@techsingularity.net: fix handling of skip bit]
Link: https://lkml.kernel.org/r/20230602111622.swtxhn6lu2qwgrwq@techsingularity.net
Link: https://lkml.kernel.org/r/20230515113344.6869-4-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Tested-by: Raghavendra K T <raghavendra.kt@amd.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Chuyi Zhou <zhouchuyi@bytedance.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-1848
commit 9ecc5fc50a9c75b0af252913163a9f1ac4206b17
Author: Mel Gorman <mgorman@techsingularity.net>
Date: Mon May 15 12:33:42 2023 +0100
mm: compaction: only force pageblock scan completion when skip hints are obeyed
fast_find_migrateblock relies on skip hints to avoid rescanning a recently
selected pageblock but compact_zone() only forces the pageblock scan
completion to set the skip hint if in direct compaction. While this
prevents direct compaction repeatedly scanning a subset of blocks due to
fast_find_migrateblock(), it does not prevent proactive compaction, node
compaction and kcompactd encountering the same problem described in commit
cfccd2e63e7e ("mm, compaction: finish pageblocks on complete migration
failure").
Force the scan completion of a pageblock to set the skip hint if skip
hints are obeyed to prevent fast_find_migrateblock() repeatedly selecting
a subset of pageblocks.
Link: https://lkml.kernel.org/r/20230515113344.6869-3-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Raghavendra K T <raghavendra.kt@amd.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Chuyi Zhou <zhouchuyi@bytedance.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-1848
commit 539aa041a9b1d98cd847b949ba8f91857c995f26
Author: Mel Gorman <mgorman@techsingularity.net>
Date: Mon May 15 12:33:41 2023 +0100
mm: compaction: ensure rescanning only happens on partially scanned pageblocks
Patch series "Follow-up "Fix excessive CPU usage during compaction"".
The series "Fix excessive CPU usage during compaction" [1] attempted to
fix a bug [2] but Vlastimil noted that the fix was incomplete [3]. While
the series was merged, fast_find_migrateblock was still disabled. This
series should fix the corner cases and allow 95e7a450b819 ("Revert
"mm/compaction: fix set skip in fast_find_migrateblock"") to be safely
reverted. Details on how many pageblocks are rescanned are in the
changelog of the last patch.
"Raghavendra K T" tested this and reported "decent improvement from perf
perspective as well as compaction related data [4]
[1] https://lore.kernel.org/r/20230125134434.18017-1-mgorman@techsingularity.net
[2] https://bugzilla.suse.com/show_bug.cgi?id=1206848
[3] https://lore.kernel.org/r/a55cf026-a2f9-ef01-9a4c-398693e048ea@suse.cz
[4] https://lkml.kernel.org/r/6d62686f-964d-342c-e085-0eae2555cc54@amd.com
This patch (of 4):
compact_zone() intends to rescan pageblocks if there is a failure to
migrate "within the current order-aligned block". However, the pageblock
scan may already be complete and moved to the next block causing the next
pageblock to be "rescanned". Ensure only the most recent pageblock is
rescanned.
Link: https://lkml.kernel.org/r/20230515113344.6869-1-mgorman@techsingularity.net
Link: https://lkml.kernel.org/r/20230515113344.6869-2-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Raghavendra K T <raghavendra.kt@amd.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Chuyi Zhou <zhouchuyi@bytedance.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-1848
commit 95e7a450b8190673675836bfef236262ceff084a
Author: Vlastimil Babka <vbabka@suse.cz>
Date: Fri Jan 13 18:33:45 2023 +0100
Revert "mm/compaction: fix set skip in fast_find_migrateblock"
This reverts commit 7efc3b7261030da79001c00d92bc3392fd6c664c.
We have got openSUSE reports (Link 1) for 6.1 kernel with khugepaged
stalling CPU for long periods of time. Investigation of tracepoint data
shows that compaction is stuck in repeating fast_find_migrateblock()
based migrate page isolation, and then fails to migrate all isolated
pages.
Commit 7efc3b726103 ("mm/compaction: fix set skip in fast_find_migrateblock")
was suspected as it was merged in 6.1 and in theory can indeed remove a
termination condition for fast_find_migrateblock() under certain
conditions, as it removes a place that always marks a scanned pageblock
from being re-scanned. There are other such places, but those can be
skipped under certain conditions, which seems to match the tracepoint
data.
Testing of revert also appears to have resolved the issue, thus revert
the commit until a more robust solution for the original problem is
developed.
It's also likely this will fix qemu stalls with 6.1 kernel reported in
Link 2, but that is not yet confirmed.
Link: https://bugzilla.suse.com/show_bug.cgi?id=1206848
Link: https://lore.kernel.org/kvm/b8017e09-f336-3035-8344-c549086c2340@kernel.org/
Link: https://lore.kernel.org/lkml/20230125134434.18017-1-mgorman@techsingularity.net/
Fixes: 7efc3b726103 ("mm/compaction: fix set skip in fast_find_migrateblock")
Cc: <stable@vger.kernel.org>
Tested-by: Pedro Falcato <pedro.falcato@gmail.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-1848
commit 7efc3b7261030da79001c00d92bc3392fd6c664c
Author: Chuyi Zhou <zhouchuyi@bytedance.com>
Date: Wed Jul 13 14:20:09 2022 +0800
mm/compaction: fix set skip in fast_find_migrateblock
When we successfully find a pageblock in fast_find_migrateblock(), the
block will be set skip-flag through set_pageblock_skip(). However, when
entering isolate_migratepages_block(), the whole pageblock will be skipped
due to the branch 'if (!valid_page && IS_ALIGNED(low_pfn,
pageblock_nr_pages))'. Eventually we will goto isolate_abort and isolate
nothing. That makes fast_find_migrateblock useless.
In this patch, when we find a suitable pageblock in
fast_find_migrateblock, we do noting but let isolate_migratepages_block to
set skip flag to the pageblock after scan it. Normally, we would isolate
some pages from the fast-find block.
I use mmtest/thpscale-madvhugepage test it. Here is the result:
baseline patch
Amean fault-both-1 1331.66 ( 0.00%) 1261.04 * 5.30%*
Amean fault-both-3 1383.95 ( 0.00%) 1191.69 * 13.89%*
Amean fault-both-5 1568.13 ( 0.00%) 1445.20 * 7.84%*
Amean fault-both-7 1819.62 ( 0.00%) 1555.13 * 14.54%*
Amean fault-both-12 1106.96 ( 0.00%) 1149.43 * -3.84%*
Amean fault-both-18 2196.93 ( 0.00%) 1875.77 * 14.62%*
Amean fault-both-24 2642.69 ( 0.00%) 2671.21 * -1.08%*
Amean fault-both-30 2901.89 ( 0.00%) 2857.32 * 1.54%*
Amean fault-both-32 3747.00 ( 0.00%) 3479.23 * 7.15%*
Link: https://lkml.kernel.org/r/20220713062009.597255-1-zhouchuyi@bytedance.com
Fixes: 70b44595ea ("mm, compaction: use free lists to quickly locate a migration source")
Signed-off-by: zhouchuyi <zhouchuyi@bytedance.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-1848
commit ee0913c4719610204315a0d8a35122c6233249e0
Author: Kefeng Wang <wangkefeng.wang@huawei.com>
Date: Wed Sep 7 14:08:44 2022 +0800
mm: add pageblock_aligned() macro
Add pageblock_aligned() and use it to simplify code.
Link: https://lkml.kernel.org/r/20220907060844.126891-3-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-1848
commit 4f9bc69ac5ce34071a9a51343bc81ca76cb2e3f1
Author: Kefeng Wang <wangkefeng.wang@huawei.com>
Date: Wed Sep 7 14:08:42 2022 +0800
mm: reuse pageblock_start/end_pfn() macro
Move pageblock_start_pfn/pageblock_end_pfn() into pageblock-flags.h, then
they could be used somewhere else, not only in compaction, also use
ALIGN_DOWN() instead of round_down() to be pair with ALIGN(), which should
be same for pageblock usage.
Link: https://lkml.kernel.org/r/20220907060844.126891-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-1848
commit b4a0215e11dcfe23a48c65c6d6c82c0c2c551a48
Author: Kefeng Wang <wangkefeng.wang@huawei.com>
Date: Sat Aug 27 19:19:59 2022 +0800
mm: fix null-ptr-deref in kswapd_is_running()
kswapd_run/stop() will set pgdat->kswapd to NULL, which could race with
kswapd_is_running() in kcompactd(),
kswapd_run/stop() kcompactd()
kswapd_is_running()
pgdat->kswapd // error or nomal ptr
verify pgdat->kswapd
// load non-NULL
pgdat->kswapd
pgdat->kswapd = NULL
task_is_running(pgdat->kswapd)
// Null pointer derefence
KASAN reports the null-ptr-deref shown below,
vmscan: Failed to start kswapd on node 0
...
BUG: KASAN: null-ptr-deref in kcompactd+0x440/0x504
Read of size 8 at addr 0000000000000024 by task kcompactd0/37
CPU: 0 PID: 37 Comm: kcompactd0 Kdump: loaded Tainted: G OE 5.10.60 #1
Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
Call trace:
dump_backtrace+0x0/0x394
show_stack+0x34/0x4c
dump_stack+0x158/0x1e4
__kasan_report+0x138/0x140
kasan_report+0x44/0xdc
__asan_load8+0x94/0xd0
kcompactd+0x440/0x504
kthread+0x1a4/0x1f0
ret_from_fork+0x10/0x18
At present kswapd/kcompactd_run() and kswapd/kcompactd_stop() are protected
by mem_hotplug_begin/done(), but without kcompactd(). There is no need to
involve memory hotplug lock in kcompactd(), so let's add a new mutex to
protect pgdat->kswapd accesses.
Also, because the kcompactd task will check the state of kswapd task, it's
better to call kcompactd_stop() before kswapd_stop() to reduce lock
conflicts.
[akpm@linux-foundation.org: add comments]
Link: https://lkml.kernel.org/r/20220827111959.186838-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
commit cfccd2e63e7e0c84c514676cffa755dd71a3b2bc
Author: Mel Gorman <mgorman@techsingularity.net>
Date: Wed Jan 25 13:44:34 2023 +0000
mm, compaction: finish pageblocks on complete migration failure
Commit 7efc3b726103 ("mm/compaction: fix set skip in
fast_find_migrateblock") address an issue where a pageblock selected by
fast_find_migrateblock() was ignored. Unfortunately, the same fix
resulted in numerous reports of khugepaged or kcompactd stalling for long
periods of time or consuming 100% of CPU.
Tracing showed that there was a lot of rescanning between a small subset
of pageblocks because the conditions for marking the block skip are not
met. The scan is not reaching the end of the pageblock because enough
pages were isolated but none were migrated successfully. Eventually it
circles back to the same block.
Pageblock skip tracking tries to minimise both latency and excessive
scanning but tracking exactly when a block is fully scanned requires an
excessive amount of state. This patch forcibly rescans a pageblock when
all isolated pages fail to migrate even though it could be for transient
reasons such as page writeback or page dirty. This will sometimes migrate
too many pages but pageblocks will be marked skip and forward progress
will be made.
"Usemen" from the mmtests configuration
workload-usemem-stress-numa-compact was used to stress compaction. The
compaction trace events were recorded using a 6.2-rc5 kernel that includes
commit 7efc3b726103 and count of unique ranges were measured. The top 5
ranges were
3076 range=(0x10ca00-0x10cc00)
3076 range=(0x110a00-0x110c00)
3098 range=(0x13b600-0x13b800)
3104 range=(0x141c00-0x141e00)
11424 range=(0x11b600-0x11b800)
While this workload is very different than what the bugs reported, the
pattern of the same subset of blocks being repeatedly scanned is observed.
At one point, *only* the range range=(0x11b600 ~ 0x11b800) was scanned
for 2 seconds. 14 seconds passed between the first migration-related
event and the last.
With the series applied including this patch, the top 5 ranges were
1 range=(0x11607e-0x116200)
1 range=(0x116200-0x116278)
1 range=(0x116278-0x116400)
1 range=(0x116400-0x116424)
1 range=(0x116424-0x116600)
Only unique ranges were scanned and the time between the first
migration-related event was 0.11 milliseconds.
Link: https://lkml.kernel.org/r/20230125134434.18017-5-mgorman@techsingularity.net
Fixes: 7efc3b726103 ("mm/compaction: fix set skip in fast_find_migrateblock")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Chuyi Zhou <zhouchuyi@bytedance.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2168372
Signed-off-by: Nico Pache <npache@redhat.com>
commit f9d7fc1ae3349759f25903cd867ab72e6ba4a63e
Author: Mel Gorman <mgorman@techsingularity.net>
Date: Wed Jan 25 13:44:33 2023 +0000
mm, compaction: finish scanning the current pageblock if requested
cc->finish_pageblock is set when the current pageblock should be rescanned
but fast_find_migrateblock can select an alternative block. Disable
fast_find_migrateblock when the current pageblock scan should be
completed.
Link: https://lkml.kernel.org/r/20230125134434.18017-4-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Chuyi Zhou <zhouchuyi@bytedance.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2168372
Signed-off-by: Nico Pache <npache@redhat.com>
commit 16b3be4034316bf56a171478cf1dccdf94dede43
Author: Mel Gorman <mgorman@techsingularity.net>
Date: Wed Jan 25 13:44:32 2023 +0000
mm, compaction: check if a page has been captured before draining PCP pages
If a page has been captured then draining is unnecssary so check first for
a captured page.
Link: https://lkml.kernel.org/r/20230125134434.18017-3-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Chuyi Zhou <zhouchuyi@bytedance.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2168372
Signed-off-by: Nico Pache <npache@redhat.com>
commit 48731c8436c68ce5597dfe72f3836bd6808bedde
Author: Mel Gorman <mgorman@techsingularity.net>
Date: Wed Jan 25 13:44:31 2023 +0000
mm, compaction: rename compact_control->rescan to finish_pageblock
Patch series "Fix excessive CPU usage during compaction".
Commit 7efc3b726103 ("mm/compaction: fix set skip in fast_find_migrateblock")
fixed a problem where pageblocks found by fast_find_migrateblock() were
ignored. Unfortunately there were numerous bug reports complaining about high
CPU usage and massive stalls once 6.1 was released. Due to the severity,
the patch was reverted by Vlastimil as a short-term fix[1] to -stable.
The underlying problem for each of the bugs is suspected to be the
repeated scanning of the same pageblocks. This series should guarantee
forward progress even with commit 7efc3b726103. More information is in
the changelog for patch 4.
[1] http://lore.kernel.org/r/20230113173345.9692-1-vbabka@suse.cz
This patch (of 4):
The rescan field was not well named albeit accurate at the time. Rename
the field to finish_pageblock to indicate that the remainder of the
pageblock should be scanned regardless of COMPACT_CLUSTER_MAX. The intent
is that pageblocks with transient failures get marked for skipping to
avoid revisiting the same pageblock.
Link: https://lkml.kernel.org/r/20230125134434.18017-2-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Chuyi Zhou <zhouchuyi@bytedance.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2168372
Signed-off-by: Nico Pache <npache@redhat.com>
commit be21b32afe470c5ae98e27e49201158a47032942
Author: NARIBAYASHI Akira <a.naribayashi@fujitsu.com>
Date: Wed Oct 26 20:24:38 2022 +0900
mm, compaction: fix fast_isolate_around() to stay within boundaries
Depending on the memory configuration, isolate_freepages_block() may scan
pages out of the target range and causes panic.
Panic can occur on systems with multiple zones in a single pageblock.
The reason it is rare is that it only happens in special
configurations. Depending on how many similar systems there are, it
may be a good idea to fix this problem for older kernels as well.
The problem is that pfn as argument of fast_isolate_around() could be out
of the target range. Therefore we should consider the case where pfn <
start_pfn, and also the case where end_pfn < pfn.
This problem should have been addressd by the commit 6e2b7044c1 ("mm,
compaction: make fast_isolate_freepages() stay within zone") but there was
an oversight.
Case1: pfn < start_pfn
<at memory compaction for node Y>
| node X's zone | node Y's zone
+-----------------+------------------------------...
pageblock ^ ^ ^
+-----------+-----------+-----------+-----------+...
^ ^ ^
^ ^ end_pfn
^ start_pfn = cc->zone->zone_start_pfn
pfn
<---------> scanned range by "Scan After"
Case2: end_pfn < pfn
<at memory compaction for node X>
| node X's zone | node Y's zone
+-----------------+------------------------------...
pageblock ^ ^ ^
+-----------+-----------+-----------+-----------+...
^ ^ ^
^ ^ pfn
^ end_pfn
start_pfn
<---------> scanned range by "Scan Before"
It seems that there is no good reason to skip nr_isolated pages just after
given pfn. So let perform simple scan from start to end instead of
dividing the scan into "Before" and "After".
Link: https://lkml.kernel.org/r/20221026112438.236336-1-a.naribayashi@fujitsu.com
Fixes: 6e2b7044c1 ("mm, compaction: make fast_isolate_freepages() stay within zone").
Signed-off-by: NARIBAYASHI Akira <a.naribayashi@fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2168372
Signed-off-by: Nico Pache <npache@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2160210
commit 9d0ddc0cb575fd41ff16131b06e08e1feac43b81
Author: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Mon Jun 6 11:53:31 2022 -0400
fs: Remove aops->migratepage()
With all users converted to migrate_folio(), remove this operation.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2160210
commit 5490da4f06d182ba944706875029e98fe7f6b821
Author: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Mon Jun 6 09:00:16 2022 -0400
fs: Add aops->migrate_folio
Provide a folio-based replacement for aops->migratepage. Update the
documentation to document migrate_folio instead of migratepage.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Conflicts: Documentation/vm/page_migration.rst - We already have
ee65728e103b ("docs: rename Documentation/vm to Documentation/mm")
sp make the change to Documentation/mm/page_migration.rst instead
Bugzilla: https://bugzilla.redhat.com/2160210
commit 68f2736a858324c3ec852f6c2cddd9d1c777357d
Author: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Tue Jun 7 15:38:48 2022 -0400
mm: Convert all PageMovable users to movable_operations
These drivers are rather uncomfortably hammered into the
address_space_operations hole. They aren't filesystems and don't behave
like filesystems. They just need their own movable_operations structure,
which we can point to directly from page->mapping.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2160210
commit b717d6b93b54ec2a2a7d3bb7268d3ff847cc54c5
Author: William Lam <william.lam@bytedance.com>
Date: Mon Jul 11 21:28:06 2022 +0100
mm: compaction: include compound page count for scanning in pageblock isolation
The number of scanned pages can be lower than the number of isolated pages
when isolating mirgratable or free pageblock. The metric is being
reported in trace event and also used in vmstat.
some example output from trace where it shows nr_taken can be greater
than nr_scanned:
Produced by kernel v5.19-rc6
kcompactd0-42 [001] ..... 1210.268022: mm_compaction_isolate_migratepages: range=(0x107ae4 ~ 0x107c00) nr_scanned=265 nr_taken=255
[...]
kcompactd0-42 [001] ..... 1210.268382: mm_compaction_isolate_freepages: range=(0x215800 ~ 0x215a00) nr_scanned=13 nr_taken=128
kcompactd0-42 [001] ..... 1210.268383: mm_compaction_isolate_freepages: range=(0x215600 ~ 0x215680) nr_scanned=1 nr_taken=128
mm_compaction_isolate_migratepages does not seem to have this
behaviour, but for the reason of consistency, nr_scanned should also be
taken care of in that side.
This behaviour is confusing since currently the count for isolated pages
takes account of compound page but not for the case of scanned pages. And
given that the number of isolated pages(nr_taken) reported in
mm_compaction_isolate_template trace event is on a single-page basis, the
ambiguity when reporting the number of scanned pages can be removed by
also including compound page count.
Link: https://lkml.kernel.org/r/20220711202806.22296-1-william.lam@bytedance.com
Signed-off-by: William Lam <william.lam@bytedance.com>
Reviewed-by: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2160210
commit e8da368a1e42a8056d1a6b419e1b91b6cf11d77e
Author: Yun-Ze Li <p76091292@gs.ncku.edu.tw>
Date: Mon Jun 20 07:15:16 2022 +0000
mm, docs: fix comments that mention mem_hotplug_end()
Comments that mention mem_hotplug_end() are confusing as there is no
function called mem_hotplug_end(). Fix them by replacing all the
occurences of mem_hotplug_end() in the comments with mem_hotplug_done().
[akpm@linux-foundation.org: grammatical fixes]
Link: https://lkml.kernel.org/r/20220620071516.1286101-1-p76091292@gs.ncku.edu.tw
Signed-off-by: Yun-Ze Li <p76091292@gs.ncku.edu.tw>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2160210
commit ca2864e52d391f8df29da78261592502ffadd9d9
Author: Miaohe Lin <linmiaohe@huawei.com>
Date: Thu Apr 28 23:16:19 2022 -0700
mm: compaction: make sure highest is above the min_pfn
It's not guaranteed that highest will be above the min_pfn. If highest is
below the min_pfn, migrate_pfn and free_pfn can meet prematurely and lead
to some useless work. Make sure highest is above min_pfn to avoid making
a futile effort.
Link: https://lkml.kernel.org/r/20220418141253.24298-13-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Charan Teja Kalla <charante@codeaurora.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pintu Kumar <pintu@codeaurora.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2160210
commit fa599c44987df43eb5cd5d60e9868fc2c790d9dc
Author: Miaohe Lin <linmiaohe@huawei.com>
Date: Thu Apr 28 23:16:19 2022 -0700
mm: compaction: simplify the code in __compact_finished
Since commit efe771c760 ("mm, compaction: always finish scanning of a
full pageblock"), compaction will always finish scanning a pageblock. And
migrate_pfn is assured to align with pageblock_nr_pages when we reach
here. So we will always return COMPACT_SUCCESS if a suitable fallback is
found due to the below IS_ALIGNED check of migrate_pfn. Simplify the code
to make this clear and improve the readability. No functional change
intended.
Link: https://lkml.kernel.org/r/20220418141253.24298-12-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Charan Teja Kalla <charante@codeaurora.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pintu Kumar <pintu@codeaurora.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2160210
commit cff387d6a2949a46d78a4f558938ef7b4cccd41f
Author: Miaohe Lin <linmiaohe@huawei.com>
Date: Thu Apr 28 23:16:18 2022 -0700
mm: compaction: make compaction_zonelist_suitable return false when COMPACT_SUCCESS
When compact_result indicates that the allocation should now succeed, i.e.
compact_result = COMPACT_SUCCESS, compaction_zonelist_suitable should
return false because there is no need to do compaction now.
Link: https://lkml.kernel.org/r/20220418141253.24298-11-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Charan Teja Kalla <charante@codeaurora.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pintu Kumar <pintu@codeaurora.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2160210
commit 3109de308987ceae413ee015038d51e2a86c7806
Author: Miaohe Lin <linmiaohe@huawei.com>
Date: Thu Apr 28 23:16:18 2022 -0700
mm: compaction: avoid possible NULL pointer dereference in kcompactd_cpu_online
It's possible that kcompactd_run could fail to run kcompactd for a hot
added node and leave pgdat->kcompactd as NULL. So pgdat->kcompactd should
be checked here to avoid possible NULL pointer dereference.
Link: https://lkml.kernel.org/r/20220418141253.24298-10-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Charan Teja Kalla <charante@codeaurora.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pintu Kumar <pintu@codeaurora.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2160210
commit 556162bf3a8c27dd6aab180e9a1427d945a708e9
Author: Miaohe Lin <linmiaohe@huawei.com>
Date: Thu Apr 28 23:16:18 2022 -0700
mm: compaction: clean up comment about async compaction in isolate_migratepages
Since commit 282722b0d2 ("mm, compaction: restrict async compaction to
pageblocks of same migratetype"), async direct compaction is restricted to
scan the pageblocks of same migratetype. Correct the comment accordingly.
Link: https://lkml.kernel.org/r/20220418141253.24298-9-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Charan Teja Kalla <charante@codeaurora.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pintu Kumar <pintu@codeaurora.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2160210
commit 66fe1cf7f581593750931266ad8f57c744e4b750
Author: Miaohe Lin <linmiaohe@huawei.com>
Date: Thu Apr 28 23:16:18 2022 -0700
mm: compaction: use helper compound_nr in isolate_migratepages_block
Use helper compound_nr to make use of compound_nr when CONFIG_64BIT and
simplify the code a bit.
Link: https://lkml.kernel.org/r/20220418141253.24298-8-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Charan Teja Kalla <charante@codeaurora.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pintu Kumar <pintu@codeaurora.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2160210
commit c036ddffe4acb0a35d2f999e3a655c89c7a5b512
Author: Miaohe Lin <linmiaohe@huawei.com>
Date: Thu Apr 28 23:16:18 2022 -0700
mm: compaction: use COMPACT_CLUSTER_MAX in compaction.c
Always use COMPACT_CLUSTER_MAX here as we're doing the compaction. Minor
improvements in readability.
Link: https://lkml.kernel.org/r/20220418141253.24298-7-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Charan Teja Kalla <charante@codeaurora.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pintu Kumar <pintu@codeaurora.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2160210
commit 85f73e6d752de325d7570293e909140bc3280d37
Author: Miaohe Lin <linmiaohe@huawei.com>
Date: Thu Apr 28 23:16:17 2022 -0700
mm: compaction: clean up comment about suitable migration target recheck
checked_pageblock is already removed and suitable_migration_target is not
rechecked under the zone lock since commit f8224aa5a0 ("mm, compaction:
do not recheck suitable_migration_target under lock"). Correct the
comment accordingly.
Link: https://lkml.kernel.org/r/20220418141253.24298-6-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Charan Teja Kalla <charante@codeaurora.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pintu Kumar <pintu@codeaurora.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2160210
commit d56c15845a5493dbe9e8b77f63418bea117d1221
Author: Miaohe Lin <linmiaohe@huawei.com>
Date: Thu Apr 28 23:16:17 2022 -0700
mm: compaction: clean up comment for sched contention
Since commit cf66f0700c ("mm, compaction: do not consider a need to
reschedule as contention"), async compaction won't abort when scheduling
is needed. Correct the relevant comment accordingly.
Link: https://lkml.kernel.org/r/20220418141253.24298-5-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Charan Teja Kalla <charante@codeaurora.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pintu Kumar <pintu@codeaurora.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2160210
commit 00bc102f82e0a0c70f1d4c9fdeb4c0cbc622d777
Author: Miaohe Lin <linmiaohe@huawei.com>
Date: Thu Apr 28 23:16:17 2022 -0700
mm: compaction: remove unneeded assignment to isolate_start_pfn
isolate_start_pfn is unused when cc->nr_freepages ! = 0. Otherwise
cc->free_pfn will overwrite it unconditionally. So we should remove this
unneeded and somewhat misleading assignment.
Link: https://lkml.kernel.org/r/20220418141253.24298-4-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Charan Teja Kalla <charante@codeaurora.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pintu Kumar <pintu@codeaurora.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2160210
commit 024c61eaff17f6a8c73cb8b25137251f0c3ef039
Author: Miaohe Lin <linmiaohe@huawei.com>
Date: Thu Apr 28 23:16:17 2022 -0700
mm: compaction: remove unneeded return value of kcompactd_run
Patch series "A few cleanup and fixup patches for compaction".
This series contains a few patches to clean up some obsolete comment,
remove unneeded return value and so on. Also we fix the possible NULL
pointer dereference. More details can be found in the respective
changelogs.
This patch (of 12):
The return value of kcompactd_run() is unused now. Clean it up.
Link: https://lkml.kernel.org/r/20220418141253.24298-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20220418141253.24298-2-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc; Mel Gorman <mgorman@techsingularity.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Pintu Kumar <pintu@codeaurora.org>
Cc: Charan Teja Kalla <charante@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2171995
commit c7e0b3d088717d148707cd6fcb12f97c6fd961c1
Author: Thomas Gleixner <tglx@linutronix.de>
Date: Thu Aug 25 18:41:29 2022 +0200
mm/compaction: Get rid of RT ifdeffery
Move the RT dependency for the initial value of
sysctl_compact_unevictable_allowed into Kconfig.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220825164131.402717-7-bigeasy@linutronix.de
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
commit 95e7a450b8190673675836bfef236262ceff084a
Author: Vlastimil Babka <vbabka@suse.cz>
Date: Fri Jan 13 18:33:45 2023 +0100
Revert "mm/compaction: fix set skip in fast_find_migrateblock"
This reverts commit 7efc3b7261030da79001c00d92bc3392fd6c664c.
We have got openSUSE reports (Link 1) for 6.1 kernel with khugepaged
stalling CPU for long periods of time. Investigation of tracepoint data
shows that compaction is stuck in repeating fast_find_migrateblock()
based migrate page isolation, and then fails to migrate all isolated
pages.
Commit 7efc3b726103 ("mm/compaction: fix set skip in fast_find_migrateblock")
was suspected as it was merged in 6.1 and in theory can indeed remove a
termination condition for fast_find_migrateblock() under certain
conditions, as it removes a place that always marks a scanned pageblock
from being re-scanned. There are other such places, but those can be
skipped under certain conditions, which seems to match the tracepoint
data.
Testing of revert also appears to have resolved the issue, thus revert
the commit until a more robust solution for the original problem is
developed.
It's also likely this will fix qemu stalls with 6.1 kernel reported in
Link 2, but that is not yet confirmed.
Link: https://bugzilla.suse.com/show_bug.cgi?id=1206848
Link: https://lore.kernel.org/kvm/b8017e09-f336-3035-8344-c549086c2340@kernel.org/
Link: https://lore.kernel.org/lkml/20230125134434.18017-1-mgorman@techsingularity.net/
Fixes: 7efc3b726103 ("mm/compaction: fix set skip in fast_find_migrateblock")
Cc: <stable@vger.kernel.org>
Tested-by: Pedro Falcato <pedro.falcato@gmail.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2166447
Signed-off-by: Nico Pache <npache@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2142505
The issue is reported when removing memory through virtio_mem device. The
transparent huge page, experienced copy-on-write fault, is wrongly
regarded as pinned. The transparent huge page is escaped from being
isolated in isolate_migratepages_block(). The transparent huge page can't
be migrated and the corresponding memory block can't be put into offline
state.
Fix it by replacing page_mapcount() with total_mapcount(). With this, the
transparent huge page can be isolated and migrated, and the memory block
can be put into offline state. Besides, The page's refcount is increased
a bit earlier to avoid the page is released when the check is executed.
Link: https://lkml.kernel.org/r/20221124095523.31061-1-gshan@redhat.com
Fixes: 1da2f328fa ("mm,thp,compaction,cma: allow THP migration for CMA allocations")
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reported-by: Zhenyu Zhang <zhenyzha@redhat.com>
Tested-by: Zhenyu Zhang <zhenyzha@redhat.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org> [5.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
(cherry picked from commit 829ae0f81ce093d674ff2256f66a714753e9ce32)
Signed-off-by: Gavin Shan <gshan@redhat.com>
commit 7efc3b7261030da79001c00d92bc3392fd6c664c
Author: Chuyi Zhou <zhouchuyi@bytedance.com>
Date: Wed Jul 13 14:20:09 2022 +0800
mm/compaction: fix set skip in fast_find_migrateblock
When we successfully find a pageblock in fast_find_migrateblock(), the
block will be set skip-flag through set_pageblock_skip(). However, when
entering isolate_migratepages_block(), the whole pageblock will be skipped
due to the branch 'if (!valid_page && IS_ALIGNED(low_pfn,
pageblock_nr_pages))'. Eventually we will goto isolate_abort and isolate
nothing. That makes fast_find_migrateblock useless.
In this patch, when we find a suitable pageblock in
fast_find_migrateblock, we do noting but let isolate_migratepages_block to
set skip flag to the pageblock after scan it. Normally, we would isolate
some pages from the fast-find block.
I use mmtest/thpscale-madvhugepage test it. Here is the result:
baseline patch
Amean fault-both-1 1331.66 ( 0.00%) 1261.04 * 5.30%*
Amean fault-both-3 1383.95 ( 0.00%) 1191.69 * 13.89%*
Amean fault-both-5 1568.13 ( 0.00%) 1445.20 * 7.84%*
Amean fault-both-7 1819.62 ( 0.00%) 1555.13 * 14.54%*
Amean fault-both-12 1106.96 ( 0.00%) 1149.43 * -3.84%*
Amean fault-both-18 2196.93 ( 0.00%) 1875.77 * 14.62%*
Amean fault-both-24 2642.69 ( 0.00%) 2671.21 * -1.08%*
Amean fault-both-30 2901.89 ( 0.00%) 2857.32 * 1.54%*
Amean fault-both-32 3747.00 ( 0.00%) 3479.23 * 7.15%*
Link: https://lkml.kernel.org/r/20220713062009.597255-1-zhouchuyi@bytedance.com
Fixes: 70b44595ea ("mm, compaction: use free lists to quickly locate a migration source")
Signed-off-by: zhouchuyi <zhouchuyi@bytedance.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2089498
Signed-off-by: Nico Pache <npache@redhat.com>
commit 4af12d04e71c2d0d961c4921602e577d6cc6010e
Author: Miaohe Lin <linmiaohe@huawei.com>
Date: Thu Apr 28 23:16:06 2022 -0700
mm: compaction: use helper isolation_suitable()
Use helper isolation_suitable() to check whether page is suitable to
isolate to simplify the code. Minor readability improvement.
Link: https://lkml.kernel.org/r/20220322110750.60311-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2089498
Signed-off-by: Nico Pache <npache@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120352
commit 31ca72fa7540bb654b55c56adaf99305847376e0
Author: Charan Teja Kalla <quic_charante@quicinc.com>
Date: Thu Apr 14 19:13:49 2022 -0700
mm: compaction: fix compiler warning when CONFIG_COMPACTION=n
The below warning is reported when CONFIG_COMPACTION=n:
mm/compaction.c:56:27: warning: 'HPAGE_FRAG_CHECK_INTERVAL_MSEC' defined but not used [-Wunused-const-variable=]
56 | static const unsigned int HPAGE_FRAG_CHECK_INTERVAL_MSEC = 500;
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Fix it by moving 'HPAGE_FRAG_CHECK_INTERVAL_MSEC' under
CONFIG_COMPACTION defconfig.
Also since this is just a 'static const int' type, use #define for it.
Link: https://lkml.kernel.org/r/1647608518-20924-1-git-send-email-quic_charante@quicinc.com
Signed-off-by: Charan Teja Kalla <quic_charante@quicinc.com>
Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Nitin Gupta <nigupta@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120352
commit abd4349ff9b8d242376b67711254221f64f447c7
Author: Baolin Wang <baolin.wang@linux.alibaba.com>
Date: Tue Mar 22 14:45:56 2022 -0700
mm: compaction: cleanup the compaction trace events
As Steven suggested [1], we should access the pointers from the trace
event to avoid dereferencing them to the tracepoint function when the
tracepoint is disabled.
[1] https://lkml.org/lkml/2021/11/3/409
Link: https://lkml.kernel.org/r/4cd393b4d57f8f01ed72c001509b28e3a3b1a8c1.1646985115.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120352
commit 89f6c88a6ab4a11deb14c270f7f1454cda4f73d6
Author: Hugh Dickins <hughd@google.com>
Date: Tue Mar 22 14:45:41 2022 -0700
mm: __isolate_lru_page_prepare() in isolate_migratepages_block()
__isolate_lru_page_prepare() conflates two unrelated functions, with the
flags to one disjoint from the flags to the other; and hides some of the
important checks outside of isolate_migratepages_block(), where the
sequence is better to be visible. It comes from the days of lumpy
reclaim, before compaction, when the combination made more sense.
Move what's needed by mm/compaction.c isolate_migratepages_block() inline
there, and what's needed by mm/vmscan.c isolate_lru_pages() inline there.
Shorten "isolate_mode" to "mode", so the sequence of conditions is easier
to read. Declare a "mapping" variable, to save one call to page_mapping()
(but not another: calling again after page is locked is necessary).
Simplify isolate_lru_pages() with a "move_to" list pointer.
Link: https://lkml.kernel.org/r/879d62a8-91cc-d3c6-fb3b-69768236df68@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Alex Shi <alexs@kernel.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/2120352
commit 84b328aa81216e08804d8875d63f26bda1298788
Author: Baolin Wang <baolin.wang@linux.alibaba.com>
Date: Fri Jan 14 14:08:40 2022 -0800
mm: compaction: fix the migration stats in trace_mm_compaction_migratepages()
Now the migrate_pages() has changed to return the number of {normal
page, THP, hugetlb} instead, thus we should not use the return value to
calculate the number of pages migrated successfully. Instead we can
just use the 'nr_succeeded' which indicates the number of normal pages
migrated successfully to calculate the non-migrated pages in
trace_mm_compaction_migratepages().
Link: https://lkml.kernel.org/r/b4225251c4bec068dcd90d275ab7de88a39e2bd7.1636275127.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Conflicts: The presence of
d1d8a3b4d06d ("mm: Turn isolate_lru_page() into folio_isolate_lru()")
causes a merge coflict due to differing context. Jus remove the
timeout argument to reclaim_throttle
Bugzilla: https://bugzilla.redhat.com/2120352
commit c3f4a9a2b082c5392fbff17c6d8551154add5fdb
Author: Mel Gorman <mgorman@techsingularity.net>
Date: Fri Nov 5 13:42:42 2021 -0700
mm/vmscan: centralise timeout values for reclaim_throttle
Neil Brown raised concerns about callers of reclaim_throttle specifying
a timeout value. The original timeout values to congestion_wait() were
probably pulled out of thin air or copy&pasted from somewhere else.
This patch centralises the timeout values and selects a timeout based on
the reason for reclaim throttling. These figures are also pulled out of
the same thin air but better values may be derived
Running a workload that is throttling for inappropriate periods and
tracing mm_vmscan_throttled can be used to pick a more appropriate
value. Excessive throttling would pick a lower timeout where as
excessive CPU usage in reclaim context would select a larger timeout.
Ideally a large value would always be used and the wakeups would occur
before a timeout but that requires careful testing.
Link: https://lkml.kernel.org/r/20211022144651.19914-7-mgorman@techsingulari
ty.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Darrick J . Wong" <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Conflicts: mm/internal.h - We already have
d1d8a3b4d06d ("mm: Turn isolate_lru_page() into folio_isolate_lru()")
so add declaration for reclaim_throttle just below the declaration for
folio_putback_lru
Bugzilla: https://bugzilla.redhat.com/2120352
commit d818fca1cac31b1fc9301bda83e195a46fb4ebaa
Author: Mel Gorman <mgorman@techsingularity.net>
Date: Fri Nov 5 13:42:29 2021 -0700
mm/vmscan: throttle reclaim and compaction when too may pages are isolated
Page reclaim throttles on congestion if too many parallel reclaim
instances have isolated too many pages. This makes no sense, excessive
parallelisation has nothing to do with writeback or congestion.
This patch creates an additional workqueue to sleep on when too many
pages are isolated. The throttled tasks are woken when the number of
isolated pages is reduced or a timeout occurs. There may be some false
positive wakeups for GFP_NOIO/GFP_NOFS callers but the tasks will
throttle again if necessary.
[shy828301@gmail.com: Wake up from compaction context]
[vbabka@suse.cz: Account number of throttled tasks only for writeback]
Link: https://lkml.kernel.org/r/20211022144651.19914-3-mgorman@techsingulari
ty.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Darrick J . Wong" <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2092667
This patch is a backport of the following upstream commit:
commit bbe832b9db2e1ad21522f8f0bf02775fff8a0e0e
Author: Rei Yamamoto <yamamoto.rei@jp.fujitsu.com>
Date: Fri May 13 16:48:57 2022 -0700
mm, compaction: fast_find_migrateblock() should return pfn in the target zone
At present, pages not in the target zone are added to cc->migratepages
list in isolate_migratepages_block(). As a result, pages may migrate
between nodes unintentionally.
This would be a serious problem for older kernels without commit
a984226f45 ("mm: memcontrol: remove the pgdata parameter of
mem_cgroup_page_lruvec"), because it can corrupt the lru list by
handling pages in list without holding proper lru_lock.
Avoid returning a pfn outside the target zone in the case that it is
not aligned with a pageblock boundary. Otherwise
isolate_migratepages_block() will handle pages not in the target zone.
Link: https://lkml.kernel.org/r/20220511044300.4069-1-yamamoto.rei@jp.fujitsu.com
Fixes: 70b44595ea ("mm, compaction: use free lists to quickly locate a migration source")
Signed-off-by: Rei Yamamoto <yamamoto.rei@jp.fujitsu.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Don Dutile <ddutile@redhat.com>
Cc: Wonhyuk Yang <vvghjk1234@gmail.com>
Cc: Rei Yamamoto <yamamoto.rei@jp.fujitsu.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2019485
Tested: ran Rafael's set of sanity tests, other than known issues, seems ok
Conflicts: due eac96c3efdb593df1a57bb5b95dbe037bfa9a522 being backported already
commit e809c3fedeeb806993349e7bf797b4c2b728be7d
Author: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Mon Jun 28 21:59:47 2021 -0400
mm/memcg: Add folio_lruvec_lock() and similar functions
These are the folio equivalents of lock_page_lruvec() and similar
functions. Also convert lruvec_memcg_debug() to take a folio.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Aristeu Rozanski <arozansk@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2019485
Tested: ran Rafael's set of sanity tests, other than known issues, seems ok
commit b1baabd995ab8e830dbf647fe731b51e12b8cedd
Author: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Mon Jun 28 20:00:28 2021 -0400
mm/memcg: Add folio_lruvec()
This replaces mem_cgroup_page_lruvec(). All callers converted.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Aristeu Rozanski <arozansk@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2023396
This patch is a backport of the following upstream commit:
commit 859a85ddf90e714092dea71a0e54c7b9896621be
Author: Mike Rapoport <rppt@kernel.org>
Date: Tue Sep 7 19:54:52 2021 -0700
mm: remove pfn_valid_within() and CONFIG_HOLES_IN_ZONE
Patch series "mm: remove pfn_valid_within() and CONFIG_HOLES_IN_ZONE".
After recent updates to freeing unused parts of the memory map, no
architecture can have holes in the memory map within a pageblock. This
makes pfn_valid_within() check and CONFIG_HOLES_IN_ZONE configuration
option redundant.
The first patch removes them both in a mechanical way and the second patch
simplifies memory_hotplug::test_pages_in_a_zone() that had
pfn_valid_within() surrounded by more logic than simple if.
This patch (of 2):
After recent changes in freeing of the unused parts of the memory map and
rework of pfn_valid() in arm and arm64 there are no architectures that can
have holes in the memory map within a pageblock and so nothing can enable
CONFIG_HOLES_IN_ZONE which guards non trivial implementation of
pfn_valid_within().
With that, pfn_valid_within() is always hardwired to 1 and can be
completely removed.
Remove calls to pfn_valid_within() and CONFIG_HOLES_IN_ZONE.
Link: https://lkml.kernel.org/r/20210713080035.7464-1-rppt@kernel.org
Link: https://lkml.kernel.org/r/20210713080035.7464-2-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2023396
This patch is a backport of the following upstream commit:
commit 65d759c8f9f57b96c199f3fe5cfb93ac7da095e9
Author: Charan Teja Reddy <charante@codeaurora.org>
Date: Thu Sep 2 14:59:59 2021 -0700
mm: compaction: support triggering of proactive compaction by user
The proactive compaction[1] gets triggered for every 500msec and run
compaction on the node for COMPACTION_HPAGE_ORDER (usually order-9) pages
based on the value set to sysctl.compaction_proactiveness. Triggering the
compaction for every 500msec in search of COMPACTION_HPAGE_ORDER pages is
not needed for all applications, especially on the embedded system
usecases which may have few MB's of RAM. Enabling the proactive
compaction in its state will endup in running almost always on such
systems.
Other side, proactive compaction can still be very much useful for getting
a set of higher order pages in some controllable manner(controlled by
using the sysctl.compaction_proactiveness). So, on systems where enabling
the proactive compaction always may proove not required, can trigger the
same from user space on write to its sysctl interface. As an example, say
app launcher decide to launch the memory heavy application which can be
launched fast if it gets more higher order pages thus launcher can prepare
the system in advance by triggering the proactive compaction from
userspace.
This triggering of proactive compaction is done on a write to
sysctl.compaction_proactiveness by user.
[1]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=facdaa917c4d5a376d09d25865f5a863f906234a
[akpm@linux-foundation.org: tweak vm.rst, per Mike]
Link: https://lkml.kernel.org/r/1627653207-12317-1-git-send-email-charante@codeaurora.org
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Rafael Aquini <aquini@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Nitin Gupta <nigupta@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2023396
This patch is a backport of the following upstream commit:
commit e1e92bfa3825b72be4957f9fef267b3106d20aa6
Author: Charan Teja Reddy <charante@codeaurora.org>
Date: Thu Sep 2 14:59:56 2021 -0700
mm: compaction: optimize proactive compaction deferrals
Vlastimil Babka figured out that when fragmentation score didn't go down
across the proactive compaction i.e. when no progress is made, next wake
up for proactive compaction is deferred for 1 << COMPACT_MAX_DEFER_SHIFT,
i.e. 64 times, with each wakeup interval of
HPAGE_FRAG_CHECK_INTERVAL_MSEC(=500). In each of this wakeup, it just
decrement 'proactive_defer' counter and goes sleep i.e. it is getting
woken to just decrement a counter.
The same deferral time can also achieved by simply doing the
HPAGE_FRAG_CHECK_INTERVAL_MSEC << COMPACT_MAX_DEFER_SHIFT thus unnecessary
wakeup of kcompact thread is avoided thus also removes the need of
'proactive_defer' thread counter.
[akpm@linux-foundation.org: tweak comment]
Link: https://lore.kernel.org/linux-fsdevel/88abfdb6-2c13-b5a6-5b46-742d12d1c910@suse.cz/
Link: https://lkml.kernel.org/r/1626869599-25412-1-git-send-email-charante@codeaurora.org
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Nitin Gupta <nigupta@nvidia.com>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2023396
This patch is a backport of the following upstream commit:
commit 5ac95884a784e822b8cbe3d4bd6e9f96b3b71e3f
Author: Yang Shi <yang.shi@linux.alibaba.com>
Date: Thu Sep 2 14:59:13 2021 -0700
mm/migrate: enable returning precise migrate_pages() success count
Under normal circumstances, migrate_pages() returns the number of pages
migrated. In error conditions, it returns an error code. When returning
an error code, there is no way to know how many pages were migrated or not
migrated.
Make migrate_pages() return how many pages are demoted successfully for
all cases, including when encountering errors. Page reclaim behavior will
depend on this in subsequent patches.
Link: https://lkml.kernel.org/r/20210721063926.3024591-3-ying.huang@intel.com
Link: https://lkml.kernel.org/r/20210715055145.195411-4-ying.huang@intel.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-by: Oscar Salvador <osalvador@suse.de> [optional parameter]
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Merge more updates from Andrew Morton:
"190 patches.
Subsystems affected by this patch series: mm (hugetlb, userfaultfd,
vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock,
migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap,
zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc,
core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs,
signals, exec, kcov, selftests, compress/decompress, and ipc"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits)
ipc/util.c: use binary search for max_idx
ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock
ipc: use kmalloc for msg_queue and shmid_kernel
ipc sem: use kvmalloc for sem_undo allocation
lib/decompressors: remove set but not used variabled 'level'
selftests/vm/pkeys: exercise x86 XSAVE init state
selftests/vm/pkeys: refill shadow register after implicit kernel write
selftests/vm/pkeys: handle negative sys_pkey_alloc() return code
selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random
kcov: add __no_sanitize_coverage to fix noinstr for all architectures
exec: remove checks in __register_bimfmt()
x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned
hfsplus: report create_date to kstat.btime
hfsplus: remove unnecessary oom message
nilfs2: remove redundant continue statement in a while-loop
kprobes: remove duplicated strong free_insn_page in x86 and s390
init: print out unknown kernel parameters
checkpatch: do not complain about positive return values starting with EPOLL
checkpatch: improve the indented label test
checkpatch: scripts/spdxcheck.py now requires python3
...
The list_splice_tail(&sublist, freelist) also do !list_empty(&sublist)
check, so remove the duplicate call.
Link: https://lkml.kernel.org/r/20210609095409.19920-1-liu.xiang@zlingsmart.com
Signed-off-by: Liu Xiang <liu.xiang@zlingsmart.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use DEVICE_ATTR_WO helper instead of plain DEVICE_ATTR, which makes the
code a bit shorter and easier to read.
Link: https://lkml.kernel.org/r/20210523064521.32912-1-yuehaibing@huawei.com
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge misc updates from Andrew Morton:
"191 patches.
Subsystems affected by this patch series: kthread, ia64, scripts,
ntfs, squashfs, ocfs2, kernel/watchdog, and mm (gup, pagealloc, slab,
slub, kmemleak, dax, debug, pagecache, gup, swap, memcg, pagemap,
mprotect, bootmem, dma, tracing, vmalloc, kasan, initialization,
pagealloc, and memory-failure)"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (191 commits)
mm,hwpoison: make get_hwpoison_page() call get_any_page()
mm,hwpoison: send SIGBUS with error virutal address
mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes
mm/page_alloc: allow high-order pages to be stored on the per-cpu lists
mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM
mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA
docs: remove description of DISCONTIGMEM
arch, mm: remove stale mentions of DISCONIGMEM
mm: remove CONFIG_DISCONTIGMEM
m68k: remove support for DISCONTIGMEM
arc: remove support for DISCONTIGMEM
arc: update comment about HIGHMEM implementation
alpha: remove DISCONTIGMEM and NUMA
mm/page_alloc: move free_the_page
mm/page_alloc: fix counting of managed_pages
mm/page_alloc: improve memmap_pages dbg msg
mm: drop SECTION_SHIFT in code comments
mm/page_alloc: introduce vm.percpu_pagelist_high_fraction
mm/page_alloc: limit the number of pages on PCP lists when reclaim is active
mm/page_alloc: scale the number of pages that are batch freed
...
All the callers of mem_cgroup_page_lruvec() just pass page_pgdat(page) as
the 2nd parameter to it (except isolate_migratepages_block()). But for
isolate_migratepages_block(), the page_pgdat(page) is also equal to the
local variable of @pgdat. So mem_cgroup_page_lruvec() do not need the
pgdat parameter. Just remove it to simplify the code.
Link: https://lkml.kernel.org/r/20210417043538.9793-4-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace a bunch of 'p->state == TASK_RUNNING' with a new helper:
task_is_running(p).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210611082838.222401495@infradead.org
Currently, migrate_[prep|finish] is merely a wrapper of
lru_cache_[disable|enable]. There is not much to gain from having
additional abstraction.
Use lru_cache_[disable|enable] instead of migrate_[prep|finish], which
would be more descriptive.
note: migrate_prep_local in compaction.c changed into lru_add_drain to
avoid CPU schedule cost with involving many other CPUs to keep old
behavior.
Link: https://lkml.kernel.org/r/20210319175127.886124-2-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Chris Goldsworthy <cgoldswo@codeaurora.org>
Cc: John Dias <joaodias@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oliver Sang <oliver.sang@intel.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
By definition, COMPACT[STALL|FAIL] events needs to be counted when there
is 'At least in one zone compaction wasn't deferred or skipped from the
direct compaction'. And when compaction is skipped or deferred,
COMPACT_SKIPPED will be returned but it will still go and update these
compaction events which is wrong in the sense that COMPACT[STALL|FAIL]
is counted without even trying the compaction.
Correct this by skipping the counting of these events when
COMPACT_SKIPPED is returned for compaction. This indirectly also avoid
the unnecessary try into the get_page_from_freelist() when compaction is
not even tried.
There is a corner case where compaction is skipped but still count
COMPACTSTALL event, which is that IRQ came and freed the page and the
same is captured in capture_control.
Link: https://lkml.kernel.org/r/1613151184-21213-1-git-send-email-charante@codeaurora.org
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The sysctl_compact_memory is mostly unused in mm/compaction.c It just
acts as a place holder for sysctl to store .data.
But the .data itself is not needed here.
So we can get ride of this variable completely and make .data as NULL.
This will also eliminate the extern declaration from header file. No
functionality is broken or changed this way.
Link: https://lkml.kernel.org/r/1614852224-14671-1-git-send-email-pintu@codeaurora.org
Signed-off-by: Pintu Kumar <pintu@codeaurora.org>
Signed-off-by: Pintu Agarwal <pintu.ping@gmail.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
alloc_contig_range() will fail if it finds a HugeTLB page within the
range, without a chance to handle them. Since HugeTLB pages can be
migrated as any LRU or Movable page, it does not make sense to bail out
without trying. Enable the interface to recognize in-use HugeTLB pages so
we can migrate them, and have much better chances to succeed the call.
Link: https://lkml.kernel.org/r/20210419075413.1064-7-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
alloc_contig_range will fail if it ever sees a HugeTLB page within the
range we are trying to allocate, even when that page is free and can be
easily reallocated.
This has proved to be problematic for some users of alloc_contic_range,
e.g: CMA and virtio-mem, where those would fail the call even when those
pages lay in ZONE_MOVABLE and are free.
We can do better by trying to replace such page.
Free hugepages are tricky to handle so as to no userspace application
notices disruption, we need to replace the current free hugepage with a
new one.
In order to do that, a new function called alloc_and_dissolve_huge_page is
introduced. This function will first try to get a new fresh hugepage, and
if it succeeds, it will replace the old one in the free hugepage pool.
The free page replacement is done under hugetlb_lock, so no external users
of hugetlb will notice the change. To allocate the new huge page, we use
alloc_buddy_huge_page(), so we do not have to deal with any counters, and
prep_new_huge_page() is not called. This is valulable because in case we
need to free the new page, we only need to call __free_pages().
Once we know that the page to be replaced is a genuine 0-refcounted huge
page, we remove the old page from the freelist by remove_hugetlb_page().
Then, we can call __prep_new_huge_page() and
__prep_account_new_huge_page() for the new huge page to properly
initialize it and increment the hstate->nr_huge_pages counter (previously
decremented by remove_hugetlb_page()). Once done, the page is enqueued by
enqueue_huge_page() and it is ready to be used.
There is one tricky case when page's refcount is 0 because it is in the
process of being released. A missing PageHugeFreed bit will tell us that
freeing is in flight so we retry after dropping the hugetlb_lock. The
race window should be small and the next retry should make a forward
progress.
E.g:
CPU0 CPU1
free_huge_page() isolate_or_dissolve_huge_page
PageHuge() == T
alloc_and_dissolve_huge_page
alloc_buddy_huge_page()
spin_lock_irq(hugetlb_lock)
// PageHuge() && !PageHugeFreed &&
// !PageCount()
spin_unlock_irq(hugetlb_lock)
spin_lock_irq(hugetlb_lock)
1) update_and_free_page
PageHuge() == F
__free_pages()
2) enqueue_huge_page
SetPageHugeFreed()
spin_unlock_irq(&hugetlb_lock)
spin_lock_irq(hugetlb_lock)
1) PageHuge() == F (freed by case#1 from CPU0)
2) PageHuge() == T
PageHugeFreed() == T
- proceed with replacing the page
In the case above we retry as the window race is quite small and we have
high chances to succeed next time.
With regard to the allocation, we restrict it to the node the page belongs
to with __GFP_THISNODE, meaning we do not fallback on other node's zones.
Note that gigantic hugetlb pages are fenced off since there is a cyclic
dependency between them and alloc_contig_range.
Link: https://lkml.kernel.org/r/20210419075413.1064-6-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, isolate_migratepages_{range,block} and their callers use a pfn
== 0 vs pfn != 0 scheme to let the caller know whether there was any error
during isolation.
This does not work as soon as we need to start reporting different error
codes and make sure we pass them down the chain, so they are properly
interpreted by functions like e.g: alloc_contig_range.
Let us rework isolate_migratepages_{range,block} so we can report error
codes. Since isolate_migratepages_block will stop returning the next pfn
to be scanned, we reuse the cc->migrate_pfn field to keep track of that.
Link: https://lkml.kernel.org/r/20210419075413.1064-3-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Compaction always operates on pages from a single given zone when
isolating both pages to migrate and freepages. Pageblock boundaries are
intersected with zone boundaries to be safe in case zone starts or ends in
the middle of pageblock. The use of pageblock_pfn_to_page() protects
against non-contiguous pageblocks.
The functions fast_isolate_freepages() and fast_isolate_around() don't
currently protect the fast freepage isolation thoroughly enough against
these corner cases, and can result in freepage isolation operate outside
of zone boundaries:
- in fast_isolate_freepages() if we get a pfn from the first pageblock
of a zone that starts in the middle of that pageblock, 'highest' can
be a pfn outside of the zone.
If we fail to isolate anything in this function, we may then call
fast_isolate_around() on a pfn outside of the zone and there
effectively do a set_pageblock_skip(page_to_pfn(highest)) which may
currently hit a VM_BUG_ON() in some configurations
- fast_isolate_around() checks only the zone end boundary and not
beginning, nor that the pageblock is contiguous (with
pageblock_pfn_to_page()) so it's possible that we end up calling
isolate_freepages_block() on a range of pfn's from two different
zones and end up e.g. isolating freepages under the wrong zone's
lock.
This patch should fix the above issues.
Link: https://lkml.kernel.org/r/20210217173300.6394-1-vbabka@suse.cz
Fixes: 5a811889de ("mm, compaction: use free lists to quickly locate a migration target")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the fast_find_migrateblock(), it iterates ocer the freelist to find the
proper pageblock. But there are some misbehaviors.
First, if the page we found is equal to cc->migrate_pfn, it is considered
that we didn't find a suitable pageblock. Secondly, if the loop was
terminated because order is less than PAGE_ALLOC_COSTLY_ORDER, it could be
considered that we found a suitable one. Thirdly, if the skip bit is set
on the page block and we goto continue, it doesn't check nr_scanned.
Fourthly, if the page block's skip bit is set, it checks that page block
is the last of list, which is unnecessary.
Link: https://lkml.kernel.org/r/20210128130411.6125-1-vvghjk1234@gmail.com
Fixes: 70b44595ea ("mm, compaction: use free lists to quickly locate a migration source")
Signed-off-by: Wonhyuk Yang <vvghjk1234@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
should_proactive_compact_node() returns true when sum of the weighted
fragmentation score of all the zones in the node is greater than the
wmark_high of compaction, which then triggers the proactive compaction
that operates on the individual zones of the node. But proactive
compaction runs on the zone only when its weighted fragmentation score
is greater than wmark_low(=wmark_high - 10).
This means that the sum of the weighted fragmentation scores of all the
zones can exceed the wmark_high but individual weighted fragmentation zone
scores can still be less than wmark_low which makes the unnecessary
trigger of the proactive compaction only to return doing nothing.
Issue with the return of proactive compaction with out even trying is its
deferral. It is simply deferred for 1 << COMPACT_MAX_DEFER_SHIFT if the
scores across the proactive compaction is same, thinking that compaction
didn't make any progress but in reality it didn't even try. With the
delay between successive retries for proactive compaction is 500msec, it
can result into the deferral for ~30sec with out even trying the proactive
compaction.
Test scenario is that: compaction_proactiveness=50 thus the wmark_low = 50
and wmark_high = 60. System have 2 zones(Normal and Movable) with sizes
5GB and 6GB respectively. After opening some apps on the android, the
weighted fragmentation scores of these zones are 47 and 49 respectively.
Since the sum of these fragmentation scores are above the wmark_high which
triggers the proactive compaction and there since the individual zones
weighted fragmentation scores are below wmark_low, it returns without
trying the proactive compaction. As a result the weighted fragmentation
scores of the zones are still 47 and 49 which makes the existing logic to
defer the compaction thinking that noprogress is made across the
compaction.
Fix this by checking just zone fragmentation score, not the weighted, in
__compact_finished() and use the zones weighted fragmentation score in
fragmentation_score_node(). In the test case above, If the weighted
average of is above wmark_high, then individual score (not adjusted) of
atleast one zone has to be above wmark_high. Thus it avoids the
unnecessary trigger and deferrals of the proactive compaction.
Link: https://lkml.kernel.org/r/1610989938-31374-1-git-send-email-charante@codeaurora.org
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nitin Gupta <ngupta@nitingupta.dev>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The VM_BUG_ON_PAGE(!PageLocked(page), page) is also done in PageMovable.
Remove this explicitly one.
Link: https://lkml.kernel.org/r/20210109081420.46030-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
isolate_migratepages_block() used rcu_read_lock() with the intention of
safeguarding against the mem_cgroup being destroyed concurrently; but
its TestClearPageLRU already protects against that. Delete the
unnecessary rcu_read_lock() and _unlock().
Hugh Dickins helped on commit log polishing, Thanks!
Link: https://lkml.kernel.org/r/1608614453-10739-3-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The parameter is redundant in the sense that it can be potentially
extracted from the "struct page" parameter by page_lru(). We need to
make sure that existing PageActive() or PageUnevictable() remains
until the function returns. A few places don't conform, and simple
reordering fixes them.
This patch may have left page_off_lru() seemingly odd, and we'll take
care of it in the next patch.
Link: https://lore.kernel.org/linux-mm/20201207220949.830352-6-yuzhao@google.com/
Link: https://lkml.kernel.org/r/20210122220600.906146-6-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The function just returns 2 results, so using a 'switch' to deal with its
result is unnecessary. Also simplify it to a bool func as Vlastimil
suggested.
Also remove 'goto' by reusing list_move(), and take Matthew Wilcox's
suggestion to update comments in function.
Link: https://lkml.kernel.org/r/728874d7-2d93-4049-68c1-dcc3b2d52ccd@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In fast_isolate_freepages, high_pfn will be used if a prefered one (ie
PFN >= low_fn) not found.
But the high_pfn is not reset before searching an free area, so when it
was used as freepage, it may from another free area searched before. As
a result move_freelist_head(freelist, freepage) will have unexpected
behavior (eg corrupt the MOVABLE freelist)
Unable to handle kernel paging request at virtual address dead000000000200
Mem abort info:
ESR = 0x96000044
Exception class = DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
Data abort info:
ISV = 0, ISS = 0x00000044
CM = 0, WnR = 1
[dead000000000200] address between user and kernel address ranges
-000|list_cut_before(inline)
-000|move_freelist_head(inline)
-000|fast_isolate_freepages(inline)
-000|isolate_freepages(inline)
-000|compaction_alloc(?, ?)
-001|unmap_and_move(inline)
-001|migrate_pages([NSD:0xFFFFFF80088CBBD0] from = 0xFFFFFF80088CBD88, [NSD:0xFFFFFF80088CBBC8] get_new_p
-002|__read_once_size(inline)
-002|static_key_count(inline)
-002|static_key_false(inline)
-002|trace_mm_compaction_migratepages(inline)
-002|compact_zone(?, [NSD:0xFFFFFF80088CBCB0] capc = 0x0)
-003|kcompactd_do_work(inline)
-003|kcompactd([X19] p = 0xFFFFFF93227FBC40)
-004|kthread([X20] _create = 0xFFFFFFE1AFB26380)
-005|ret_from_fork(asm)
The issue was reported on an smart phone product with 6GB ram and 3GB
zram as swap device.
This patch fixes the issue by reset high_pfn before searching each free
area, which ensure freepage and freelist match when call
move_freelist_head in fast_isolate_freepages().
Link: http://lkml.kernel.org/r/20190118175136.31341-12-mgorman@techsingularity.net
Link: https://lkml.kernel.org/r/20210112094720.1238444-1-wu-yan@tcl.com
Fixes: 5a811889de ("mm, compaction: use free lists to quickly locate a migration target")
Signed-off-by: Rokudo Yan <wu-yan@tcl.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch moves per node lru_lock into lruvec, thus bring a lru_lock for
each of memcg per node. So on a large machine, each of memcg don't have
to suffer from per node pgdat->lru_lock competition. They could go fast
with their self lru_lock.
After move memcg charge before lru inserting, page isolation could
serialize page's memcg, then per memcg lruvec lock is stable and could
replace per node lru lock.
In isolate_migratepages_block(), compact_unlock_should_abort and
lock_page_lruvec_irqsave are open coded to work with compact_control.
Also add a debug func in locking which may give some clues if there are
sth out of hands.
Daniel Jordan's testing show 62% improvement on modified readtwice case on
his 2P * 10 core * 2 HT broadwell box.
https://lore.kernel.org/lkml/20200915165807.kpp7uhiw7l3loofu@ca-dmjordan1.us.oracle.com/
Hugh Dickins helped on the patch polish, thanks!
[alex.shi@linux.alibaba.com: fix comment typo]
Link: https://lkml.kernel.org/r/5b085715-292a-4b43-50b3-d73dc90d1de5@linux.alibaba.com
[alex.shi@linux.alibaba.com: use page_memcg()]
Link: https://lkml.kernel.org/r/5a4c2b72-7ee8-2478-fc0e-85eb83aafec4@linux.alibaba.com
Link: https://lkml.kernel.org/r/1604566549-62481-18-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rong Chen <rong.a.chen@intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, compaction would get the lru_lock and then do page isolation
which works fine with pgdat->lru_lock, since any page isoltion would
compete for the lru_lock. If we want to change to memcg lru_lock, we have
to isolate the page before getting lru_lock, thus isoltion would block
page's memcg change which relay on page isoltion too. Then we could
safely use per memcg lru_lock later.
The new page isolation use previous introduced TestClearPageLRU() + pgdat
lru locking which will be changed to memcg lru lock later.
Hugh Dickins <hughd@google.com> fixed following bugs in this patch's early
version:
Fix lots of crashes under compaction load: isolate_migratepages_block()
must clean up appropriately when rejecting a page, setting PageLRU again
if it had been cleared; and a put_page() after get_page_unless_zero()
cannot safely be done while holding locked_lruvec - it may turn out to be
the final put_page(), which will take an lruvec lock when PageLRU.
And move __isolate_lru_page_prepare back after get_page_unless_zero to
make trylock_page() safe: trylock_page() is not safe to use at this time:
its setting PG_locked can race with the page being freed or allocated
("Bad page"), and can also erase flags being set by one of those "sole
owners" of a freshly allocated page who use non-atomic __SetPageFlag().
Link: https://lkml.kernel.org/r/1604566549-62481-16-git-send-email-alex.shi@linux.alibaba.com
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
defer_compaction() and compaction_deferred() and compaction_restarting()
in mm/compaction.c won't be used in other files, so make them static, and
remove the declaration in the header file.
Take the chance to fix a typo.
Link: https://lkml.kernel.org/r/20201123170801.GA9625@rlk
Signed-off-by: Hui Su <sh_def@163.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Nitin Gupta <nigupta@nvidia.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit 837d026d56 ("mm/compaction: more trace to understand
when/why compaction start/finish"), the comment place is not suitable.
So move compaction_suitable's comment to right place.
Link: https://lkml.kernel.org/r/20201116144121.GA385717@rlk
Signed-off-by: Hui Su <sh_def@163.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are two 'start_pfn' declared in compact_zone() which have different
meanings. Rename the second one to 'iteration_start_pfn' to prevent
confusion.
Also, remove an useless semicolon.
Link: https://lkml.kernel.org/r/20201019115044.1571-1-yanfei.xu@windriver.com
Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In isolate_migratepages_block, if we have too many isolated pages and
nr_migratepages is not zero, we should try to migrate what we have
without wasting time on isolating.
In theory it's possible that multiple parallel compactions will cause
too_many_isolated() to become true even if each has isolated less than
COMPACT_CLUSTER_MAX, and loop forever in the while loop. Bailing
immediately prevents that.
[vbabka@suse.cz: changelog addition]
Fixes: 1da2f328fa (“mm,thp,compaction,cma: allow THP migration for CMA allocations”)
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@vger.kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Yang Shi <shy828301@gmail.com>
Link: https://lkml.kernel.org/r/20201030183809.3616803-2-zi.yan@sent.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In isolate_migratepages_block, when cc->alloc_contig is true, we are
able to isolate compound pages. But nr_migratepages and nr_isolated did
not count compound pages correctly, causing us to isolate more pages
than we thought.
So count compound pages as the number of base pages they contain.
Otherwise, we might be trapped in too_many_isolated while loop, since
the actual isolated pages can go up to COMPACT_CLUSTER_MAX*512=16384,
where COMPACT_CLUSTER_MAX is 32, since we stop isolation after
cc->nr_migratepages reaches to COMPACT_CLUSTER_MAX.
In addition, after we fix the issue above, cc->nr_migratepages could
never be equal to COMPACT_CLUSTER_MAX if compound pages are isolated,
thus page isolation could not stop as we intended. Change the isolation
stop condition to '>='.
The issue can be triggered as follows:
In a system with 16GB memory and an 8GB CMA region reserved by
hugetlb_cma, if we first allocate 10GB THPs and mlock them (so some THPs
are allocated in the CMA region and mlocked), reserving 6 1GB hugetlb
pages via /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages will
get stuck (looping in too_many_isolated function) until we kill either
task. With the patch applied, oom will kill the application with 10GB
THPs and let hugetlb page reservation finish.
[ziy@nvidia.com: v3]
Link: https://lkml.kernel.org/r/20201030183809.3616803-1-zi.yan@sent.com
Fixes: 1da2f328fa ("cmm,thp,compaction,cma: allow THP migration for CMA allocations")
Signed-off-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Rik van Riel <riel@surriel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201029200435.3386066-1-zi.yan@sent.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current page_order() can only be called on pages in the buddy
allocator. For compound pages, you have to use compound_order(). This is
confusing and led to a bug, so rename page_order() to buddy_order().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20201001152259.14932-2-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The same code can work both for 'zone->compact_considered > defer_limit'
and 'zone->compact_considered >= defer_limit'. In the latter there is one
branch less which is more effective considering performance.
Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Link: https://lkml.kernel.org/r/20200913190448.28649-1-mateusznosek0@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The thp prefix is more frequently used than hpage and we should be
consistent between the various functions.
[akpm@linux-foundation.org: fix mm/migrate.c]
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/r/20200629151959.15779-6-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Drop the repeated word "a".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Link: http://lkml.kernel.org/r/20200801173822.14973-2-rdunlap@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is no compact_defer_limit. It should be compact_defer_shift in
use. and add compact_order_failed explanation.
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Link: http://lkml.kernel.org/r/3bd60e1b-a74e-050d-ade4-6e8f54e00b92@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Proactive compaction uses per-node/zone "fragmentation score" which is
always in range [0, 100], so use unsigned type of these scores as well as
for related constants.
Signed-off-by: Nitin Gupta <nigupta@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Link: http://lkml.kernel.org/r/20200618010319.13159-1-nigupta@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix compile error when COMPACTION_HPAGE_ORDER is assigned to
HUGETLB_PAGE_ORDER. The correct way to check if this constant is defined
is to check for CONFIG_HUGETLBFS.
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Nitin Gupta <nigupta@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: http://lkml.kernel.org/r/20200623064544.25766-1-nigupta@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For some applications, we need to allocate almost all memory as hugepages.
However, on a running system, higher-order allocations can fail if the
memory is fragmented. Linux kernel currently does on-demand compaction as
we request more hugepages, but this style of compaction incurs very high
latency. Experiments with one-time full memory compaction (followed by
hugepage allocations) show that kernel is able to restore a highly
fragmented memory state to a fairly compacted memory state within <1 sec
for a 32G system. Such data suggests that a more proactive compaction can
help us allocate a large fraction of memory as hugepages keeping
allocation latencies low.
For a more proactive compaction, the approach taken here is to define a
new sysctl called 'vm.compaction_proactiveness' which dictates bounds for
external fragmentation which kcompactd tries to maintain.
The tunable takes a value in range [0, 100], with a default of 20.
Note that a previous version of this patch [1] was found to introduce too
many tunables (per-order extfrag{low, high}), but this one reduces them to
just one sysctl. Also, the new tunable is an opaque value instead of
asking for specific bounds of "external fragmentation", which would have
been difficult to estimate. The internal interpretation of this opaque
value allows for future fine-tuning.
Currently, we use a simple translation from this tunable to [low, high]
"fragmentation score" thresholds (low=100-proactiveness, high=low+10%).
The score for a node is defined as weighted mean of per-zone external
fragmentation. A zone's present_pages determines its weight.
To periodically check per-node score, we reuse per-node kcompactd threads,
which are woken up every 500 milliseconds to check the same. If a node's
score exceeds its high threshold (as derived from user-provided
proactiveness value), proactive compaction is started until its score
reaches its low threshold value. By default, proactiveness is set to 20,
which implies threshold values of low=80 and high=90.
This patch is largely based on ideas from Michal Hocko [2]. See also the
LWN article [3].
Performance data
================
System: x64_64, 1T RAM, 80 CPU threads.
Kernel: 5.6.0-rc3 + this patch
echo madvise | sudo tee /sys/kernel/mm/transparent_hugepage/enabled
echo madvise | sudo tee /sys/kernel/mm/transparent_hugepage/defrag
Before starting the driver, the system was fragmented from a userspace
program that allocates all memory and then for each 2M aligned section,
frees 3/4 of base pages using munmap. The workload is mainly anonymous
userspace pages, which are easy to move around. I intentionally avoided
unmovable pages in this test to see how much latency we incur when
hugepage allocations hit direct compaction.
1. Kernel hugepage allocation latencies
With the system in such a fragmented state, a kernel driver then allocates
as many hugepages as possible and measures allocation latency:
(all latency values are in microseconds)
- With vanilla 5.6.0-rc3
percentile latency
–––––––––– –––––––
5 7894
10 9496
25 12561
30 15295
40 18244
50 21229
60 27556
75 30147
80 31047
90 32859
95 33799
Total 2M hugepages allocated = 383859 (749G worth of hugepages out of 762G
total free => 98% of free memory could be allocated as hugepages)
- With 5.6.0-rc3 + this patch, with proactiveness=20
sysctl -w vm.compaction_proactiveness=20
percentile latency
–––––––––– –––––––
5 2
10 2
25 3
30 3
40 3
50 4
60 4
75 4
80 4
90 5
95 429
Total 2M hugepages allocated = 384105 (750G worth of hugepages out of 762G
total free => 98% of free memory could be allocated as hugepages)
2. JAVA heap allocation
In this test, we first fragment memory using the same method as for (1).
Then, we start a Java process with a heap size set to 700G and request the
heap to be allocated with THP hugepages. We also set THP to madvise to
allow hugepage backing of this heap.
/usr/bin/time
java -Xms700G -Xmx700G -XX:+UseTransparentHugePages -XX:+AlwaysPreTouch
The above command allocates 700G of Java heap using hugepages.
- With vanilla 5.6.0-rc3
17.39user 1666.48system 27:37.89elapsed
- With 5.6.0-rc3 + this patch, with proactiveness=20
8.35user 194.58system 3:19.62elapsed
Elapsed time remains around 3:15, as proactiveness is further increased.
Note that proactive compaction happens throughout the runtime of these
workloads. The situation of one-time compaction, sufficient to supply
hugepages for following allocation stream, can probably happen for more
extreme proactiveness values, like 80 or 90.
In the above Java workload, proactiveness is set to 20. The test starts
with a node's score of 80 or higher, depending on the delay between the
fragmentation step and starting the benchmark, which gives more-or-less
time for the initial round of compaction. As t he benchmark consumes
hugepages, node's score quickly rises above the high threshold (90) and
proactive compaction starts again, which brings down the score to the low
threshold level (80). Repeat.
bpftrace also confirms proactive compaction running 20+ times during the
runtime of this Java benchmark. kcompactd threads consume 100% of one of
the CPUs while it tries to bring a node's score within thresholds.
Backoff behavior
================
Above workloads produce a memory state which is easy to compact. However,
if memory is filled with unmovable pages, proactive compaction should
essentially back off. To test this aspect:
- Created a kernel driver that allocates almost all memory as hugepages
followed by freeing first 3/4 of each hugepage.
- Set proactiveness=40
- Note that proactive_compact_node() is deferred maximum number of times
with HPAGE_FRAG_CHECK_INTERVAL_MSEC of wait between each check
(=> ~30 seconds between retries).
[1] https://patchwork.kernel.org/patch/11098289/
[2] https://lore.kernel.org/linux-mm/20161230131412.GI13301@dhcp22.suse.cz/
[3] https://lwn.net/Articles/817905/
Signed-off-by: Nitin Gupta <nigupta@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Oleksandr Natalenko <oleksandr@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Reviewed-by: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Nitin Gupta <ngupta@nitingupta.dev>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Link: http://lkml.kernel.org/r/20200616204527.19185-1-nigupta@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh reports:
"While stressing compaction, one run oopsed on NULL capc->cc in
__free_one_page()'s task_capc(zone): compact_zone_order() had been
interrupted, and a page was being freed in the return from interrupt.
Though you would not expect it from the source, both gccs I was using
(4.8.1 and 7.5.0) had chosen to compile compact_zone_order() with the
".cc = &cc" implemented by mov %rbx,-0xb0(%rbp) immediately before
callq compact_zone - long after the "current->capture_control =
&capc". An interrupt in between those finds capc->cc NULL (zeroed by
an earlier rep stos).
This could presumably be fixed by a barrier() before setting
current->capture_control in compact_zone_order(); but would also need
more care on return from compact_zone(), in order not to risk leaking
a page captured by interrupt just before capture_control is reset.
Maybe that is the preferable fix, but I felt safer for task_capc() to
exclude the rather surprising possibility of capture at interrupt
time"
I have checked that gcc10 also behaves the same.
The advantage of fix in compact_zone_order() is that we don't add
another test in the page freeing hot path, and that it might prevent
future problems if we stop exposing pointers to uninitialized structures
in current task.
So this patch implements the suggestion for compact_zone_order() with
barrier() (and WRITE_ONCE() to prevent store tearing) for setting
current->capture_control, and prevents page leaking with
WRITE_ONCE/READ_ONCE in the proper order.
Link: http://lkml.kernel.org/r/20200616082649.27173-1-vbabka@suse.cz
Fixes: 5e1f0f098b ("mm, compaction: capture a page under direct compaction")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Hugh Dickins <hughd@google.com>
Suggested-by: Hugh Dickins <hughd@google.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Li Wang <liwang@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org> [5.1+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a typo in comment, fix it.
Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200411070307.16021-1-ethp@qq.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge more updates from Andrew Morton:
"More mm/ work, plenty more to come
Subsystems affected by this patch series: slub, memcg, gup, kasan,
pagealloc, hugetlb, vmscan, tools, mempolicy, memblock, hugetlbfs,
thp, mmap, kconfig"
* akpm: (131 commits)
arm64: mm: use ARCH_HAS_DEBUG_WX instead of arch defined
x86: mm: use ARCH_HAS_DEBUG_WX instead of arch defined
riscv: support DEBUG_WX
mm: add DEBUG_WX support
drivers/base/memory.c: cache memory blocks in xarray to accelerate lookup
mm/thp: rename pmd_mknotpresent() as pmd_mkinvalid()
powerpc/mm: drop platform defined pmd_mknotpresent()
mm: thp: don't need to drain lru cache when splitting and mlocking THP
hugetlbfs: get unmapped area below TASK_UNMAPPED_BASE for hugetlbfs
sparc32: register memory occupied by kernel as memblock.memory
include/linux/memblock.h: fix minor typo and unclear comment
mm, mempolicy: fix up gup usage in lookup_node
tools/vm/page_owner_sort.c: filter out unneeded line
mm: swap: memcg: fix memcg stats for huge pages
mm: swap: fix vmstats for huge pages
mm: vmscan: limit the range of LRU type balancing
mm: vmscan: reclaim writepage is IO cost
mm: vmscan: determine anon/file pressure balance at the reclaim root
mm: balance LRU lists based on relative thrashing
mm: only count actual rotations as LRU reclaim cost
...
Pageblock migrate type is encoded in GFP flags, just as zone_type and
zonelist.
Currently we use gfp_zone() and gfp_zonelist() to extract related
information, it would be proper to use the same naming convention for
migrate type.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Link: http://lkml.kernel.org/r/20200329080823.7735-1-richard.weiyang@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
classzone_idx is just different name for high_zoneidx now. So, integrate
them and add some comment to struct alloc_context in order to reduce
future confusion about the meaning of this variable.
The accessor, ac_classzone_idx() is also removed since it isn't needed
after integration.
In addition to integration, this patch also renames high_zoneidx to
highest_zoneidx since it represents more precise meaning.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Baoquan He <bhe@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ye Xiaolong <xiaolong.ye@intel.com>
Link: http://lkml.kernel.org/r/1587095923-7515-3-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Aristeu Rozanski
Paolo Bonzini
Chris von Recklinghausen
Nico Pache
Juri Lelli
Gavin Shan
Rafael Aquini
Linus Torvalds
Wonhyuk Yang
Liu Xiang
YueHaibing
Muchun Song
Peter Zijlstra
Ingo Molnar
Zhiyuan Dai
Minchan Kim
Charan Teja Reddy
Pintu Kumar
Oscar Salvador
Vlastimil Babka
Miaohe Lin
Alex Shi
Yu Zhao
Rokudo Yan
Hui Su
Yanfei Xu
Zi Yan
Matthew Wilcox (Oracle)
Mateusz Nosek
Randy Dunlap
Nitin Gupta
Ethon Paul
Wei Yang
Joonsoo Kim