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Antoine Tenart bfb167760c rtnetlink: Add per-netns RTNL.
JIRA: https://issues.redhat.com/browse/RHEL-150155
Upstream Status: linux.git
Conflicts:\
- Context differences as upstream commit c353e8983e0d "(net: introduce per netns
  packet chains"), 844e5e7e656d ("rtnetlink: Add assertion helpers for
  per-netns RTNL.") and eafb64f40ca4 ("vsock: add netns to vsock core") were
  backported before in c10s.

commit 76aed95319da25d6884dff01d5f0149e4b542f96
Author: Kuniyuki Iwashima <kuniyu@amazon.com>
Date:   Fri Oct 4 15:10:29 2024 -0700

    rtnetlink: Add per-netns RTNL.

    The goal is to break RTNL down into per-netns mutex.

    This patch adds per-netns mutex and its helper functions, rtnl_net_lock()
    and rtnl_net_unlock().

    rtnl_net_lock() acquires the global RTNL and per-netns RTNL mutex, and
    rtnl_net_unlock() releases them.

    We will replace 800+ rtnl_lock() with rtnl_net_lock() and finally removes
    rtnl_lock() in rtnl_net_lock().

    When we need to nest per-netns RTNL mutex, we will use __rtnl_net_lock(),
    and its locking order is defined by rtnl_net_lock_cmp_fn() as follows:

      1. init_net is first
      2. netns address ascending order

    Note that the conversion will be done under CONFIG_DEBUG_NET_SMALL_RTNL
    with LOCKDEP so that we can carefully add the extra mutex without slowing
    down RTNL operations during conversion.

    Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
    Reviewed-by: Eric Dumazet <edumazet@google.com>
    Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Signed-off-by: Antoine Tenart <atenart@redhat.com>
2026-02-17 14:53:12 +01:00

42 lines
1.3 KiB
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# SPDX-License-Identifier: GPL-2.0-only
config NET_DEV_REFCNT_TRACKER
bool "Enable net device refcount tracking"
depends on DEBUG_KERNEL && STACKTRACE_SUPPORT && NET
select REF_TRACKER
default n
help
Enable debugging feature to track device references.
This adds memory and cpu costs.
config NET_NS_REFCNT_TRACKER
bool "Enable networking namespace refcount tracking"
depends on DEBUG_KERNEL && STACKTRACE_SUPPORT && NET
select REF_TRACKER
default n
help
Enable debugging feature to track netns references.
This adds memory and cpu costs.
config DEBUG_NET
bool "Add generic networking debug"
depends on DEBUG_KERNEL && NET
help
Enable extra sanity checks in networking.
This is mostly used by fuzzers, but is safe to select.
config DEBUG_NET_SMALL_RTNL
bool "Add extra per-netns mutex inside RTNL"
depends on DEBUG_KERNEL && NET && LOCK_DEBUGGING_SUPPORT
select PROVE_LOCKING
default n
help
rtnl_lock() is being replaced with rtnl_net_lock() that
acquires the global RTNL and a small per-netns RTNL mutex.
During the conversion, rtnl_net_lock() just adds an extra
mutex in every RTNL scope and slows down the operations.
Once the conversion completes, rtnl_lock() will be removed
and rtnetlink will gain per-netns scalability.