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Add single-threaded path to malloc/realloc/calloc/memalloc 

This patch adds a single-threaded fast path to malloc, realloc,
calloc and memalloc.  When we're single-threaded, we can bypass
arena_get (which always locks the arena it returns) and just use
the main arena.  Also avoid retrying a different arena since
there is just the main arena.

	* malloc/malloc.c (__libc_malloc): Add SINGLE_THREAD_P path.
	(__libc_realloc): Likewise.
	(_mid_memalign): Likewise.
	(__libc_calloc): Likewise.
This commit is contained in:
Wilco Dijkstra 2017-10-24 12:39:24 +01:00
parent 1d479c8c33
commit 3f6bb8a32e
2 changed files with 48 additions and 9 deletions
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7
ChangeLog
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@ -1,3 +1,10 @@
2017-10-23 Wilco Dijkstra <wdijkstr@arm.com>
* malloc/malloc.c (__libc_malloc): Add SINGLE_THREAD_P path.
(__libc_realloc): Likewise.
(_mid_memalign): Likewise.
(__libc_calloc): Likewise.
2017-10-23 Mike FABIAN <mfabian@redhat.com>
* localedata/locales/tpi_PG (LC_MESSAGES): Fix yesexpr and noexpr

50
malloc/malloc.c
View File

@ -3038,6 +3038,14 @@ __libc_malloc (size_t bytes)
DIAG_POP_NEEDS_COMMENT;
#endif
if (SINGLE_THREAD_P)
{
victim = _int_malloc (&main_arena, bytes);
assert (!victim || chunk_is_mmapped (mem2chunk (victim)) ||
&main_arena == arena_for_chunk (mem2chunk (victim)));
return victim;
}
arena_get (ar_ptr, bytes);
victim = _int_malloc (ar_ptr, bytes);
@ -3194,6 +3202,15 @@ __libc_realloc (void *oldmem, size_t bytes)
return newmem;
}
if (SINGLE_THREAD_P)
{
newp = _int_realloc (ar_ptr, oldp, oldsize, nb);
assert (!newp || chunk_is_mmapped (mem2chunk (newp)) ||
ar_ptr == arena_for_chunk (mem2chunk (newp)));
return newp;
}
__libc_lock_lock (ar_ptr->mutex);
newp = _int_realloc (ar_ptr, oldp, oldsize, nb);
@ -3269,6 +3286,15 @@ _mid_memalign (size_t alignment, size_t bytes, void *address)
alignment = a;
}
if (SINGLE_THREAD_P)
{
p = _int_memalign (&main_arena, alignment, bytes);
assert (!p || chunk_is_mmapped (mem2chunk (p)) ||
&main_arena == arena_for_chunk (mem2chunk (p)));
return p;
}
arena_get (ar_ptr, bytes + alignment + MINSIZE);
p = _int_memalign (ar_ptr, alignment, bytes);
@ -3361,7 +3387,11 @@ __libc_calloc (size_t n, size_t elem_size)
MAYBE_INIT_TCACHE ();
arena_get (av, sz);
if (SINGLE_THREAD_P)
av = &main_arena;
else
arena_get (av, sz);
if (av)
{
/* Check if we hand out the top chunk, in which case there may be no
@ -3391,19 +3421,21 @@ __libc_calloc (size_t n, size_t elem_size)
}
mem = _int_malloc (av, sz);
assert (!mem || chunk_is_mmapped (mem2chunk (mem)) ||
av == arena_for_chunk (mem2chunk (mem)));
if (mem == 0 && av != NULL)
if (!SINGLE_THREAD_P)
{
LIBC_PROBE (memory_calloc_retry, 1, sz);
av = arena_get_retry (av, sz);
mem = _int_malloc (av, sz);
}
if (mem == 0 && av != NULL)
{
LIBC_PROBE (memory_calloc_retry, 1, sz);
av = arena_get_retry (av, sz);
mem = _int_malloc (av, sz);
}
if (av != NULL)
__libc_lock_unlock (av->mutex);
if (av != NULL)
__libc_lock_unlock (av->mutex);
}
/* Allocation failed even after a retry. */
if (mem == 0)