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Re: [PATCH] Cleanup code duplication in malloc on fallback to useanother arena
- From: Siddhesh Poyarekar <siddhesh at redhat dot com>
- To: Andreas Schwab <schwab at linux-m68k dot org>
- Cc: libc-alpha at sourceware dot org
- Date: Thu, 30 Aug 2012 15:44:12 +0530
- Subject: Re: [PATCH] Cleanup code duplication in malloc on fallback to useanother arena
- References: <20120830145849.7d2fdf04@spoyarek><m24nnku33g.fsf@igel.home>
On Thu, 30 Aug 2012 11:43:47 +0200, Andreas wrote:
> There should be no need to mark a static function internal_function,
> since the compiler can already freely chose the calling convention.
>
Right, thanks. Updated patch attached.
Regards,
Siddhesh
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 0f1796c..8ecd44f 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -2838,6 +2838,27 @@ mremap_chunk(mchunkptr p, size_t new_size)
#endif /* HAVE_MREMAP */
+/* If we don't have the main arena, then maybe the failure is due to running
+ out of mmapped areas, so we can try allocating on the main arena.
+ Otherwise, it is likely that sbrk() has failed and there is still a chance
+ to mmap(), so try one one of the other arenas. */
+static mstate
+get_another_arena(mstate ar_ptr, size_t bytes)
+{
+ if(ar_ptr != &main_arena) {
+ (void)mutex_unlock(&ar_ptr->mutex);
+ ar_ptr = &main_arena;
+ (void)mutex_lock(&ar_ptr->mutex);
+ } else {
+ /* Grab ar_ptr->next prior to releasing its lock. */
+ mstate prev = ar_ptr->next ? ar_ptr : 0;
+ (void)mutex_unlock(&ar_ptr->mutex);
+ ar_ptr = arena_get2(prev, bytes, ar_ptr);
+ }
+
+ return ar_ptr;
+}
+
/*------------------------ Public wrappers. --------------------------------*/
void*
@@ -2858,23 +2879,10 @@ __libc_malloc(size_t bytes)
return 0;
victim = _int_malloc(ar_ptr, bytes);
if(!victim) {
- /* Maybe the failure is due to running out of mmapped areas. */
- if(ar_ptr != &main_arena) {
- (void)mutex_unlock(&ar_ptr->mutex);
- ar_ptr = &main_arena;
- (void)mutex_lock(&ar_ptr->mutex);
+ ar_ptr = get_another_arena(ar_ptr, bytes);
+ if (__builtin_expect(ar_ptr != NULL, 1)) {
victim = _int_malloc(ar_ptr, bytes);
(void)mutex_unlock(&ar_ptr->mutex);
- } else {
- /* ... or sbrk() has failed and there is still a chance to mmap()
- Grab ar_ptr->next prior to releasing its lock. */
- mstate prev = ar_ptr->next ? ar_ptr : 0;
- (void)mutex_unlock(&ar_ptr->mutex);
- ar_ptr = arena_get2(prev, bytes, ar_ptr);
- if(ar_ptr) {
- victim = _int_malloc(ar_ptr, bytes);
- (void)mutex_unlock(&ar_ptr->mutex);
- }
}
} else
(void)mutex_unlock(&ar_ptr->mutex);
@@ -3038,23 +3046,10 @@ __libc_memalign(size_t alignment, size_t bytes)
return 0;
p = _int_memalign(ar_ptr, alignment, bytes);
if(!p) {
- /* Maybe the failure is due to running out of mmapped areas. */
- if(ar_ptr != &main_arena) {
- (void)mutex_unlock(&ar_ptr->mutex);
- ar_ptr = &main_arena;
- (void)mutex_lock(&ar_ptr->mutex);
+ ar_ptr = get_another_arena (ar_ptr, bytes);
+ if (__builtin_expect(ar_ptr != NULL, 1)) {
p = _int_memalign(ar_ptr, alignment, bytes);
(void)mutex_unlock(&ar_ptr->mutex);
- } else {
- /* ... or sbrk() has failed and there is still a chance to mmap()
- Grab ar_ptr->next prior to releasing its lock. */
- mstate prev = ar_ptr->next ? ar_ptr : 0;
- (void)mutex_unlock(&ar_ptr->mutex);
- ar_ptr = arena_get2(prev, bytes, ar_ptr);
- if(ar_ptr) {
- p = _int_memalign(ar_ptr, alignment, bytes);
- (void)mutex_unlock(&ar_ptr->mutex);
- }
}
} else
(void)mutex_unlock(&ar_ptr->mutex);
@@ -3088,23 +3083,10 @@ __libc_valloc(size_t bytes)
return 0;
p = _int_valloc(ar_ptr, bytes);
if(!p) {
- /* Maybe the failure is due to running out of mmapped areas. */
- if(ar_ptr != &main_arena) {
- (void)mutex_unlock(&ar_ptr->mutex);
- ar_ptr = &main_arena;
- (void)mutex_lock(&ar_ptr->mutex);
+ ar_ptr = get_another_arena (ar_ptr, bytes);
+ if (__builtin_expect(ar_ptr != NULL, 1)) {
p = _int_memalign(ar_ptr, pagesz, bytes);
(void)mutex_unlock(&ar_ptr->mutex);
- } else {
- /* ... or sbrk() has failed and there is still a chance to mmap()
- Grab ar_ptr->next prior to releasing its lock. */
- mstate prev = ar_ptr->next ? ar_ptr : 0;
- (void)mutex_unlock(&ar_ptr->mutex);
- ar_ptr = arena_get2(prev, bytes, ar_ptr);
- if(ar_ptr) {
- p = _int_memalign(ar_ptr, pagesz, bytes);
- (void)mutex_unlock(&ar_ptr->mutex);
- }
}
} else
(void)mutex_unlock (&ar_ptr->mutex);
@@ -3136,23 +3118,10 @@ __libc_pvalloc(size_t bytes)
arena_get(ar_ptr, bytes + 2*pagesz + MINSIZE);
p = _int_pvalloc(ar_ptr, bytes);
if(!p) {
- /* Maybe the failure is due to running out of mmapped areas. */
- if(ar_ptr != &main_arena) {
- (void)mutex_unlock(&ar_ptr->mutex);
- ar_ptr = &main_arena;
- (void)mutex_lock(&ar_ptr->mutex);
+ ar_ptr = get_another_arena (ar_ptr, bytes + 2*pagesz + MINSIZE);
+ if (__builtin_expect(ar_ptr != NULL, 1)) {
p = _int_memalign(ar_ptr, pagesz, rounded_bytes);
(void)mutex_unlock(&ar_ptr->mutex);
- } else {
- /* ... or sbrk() has failed and there is still a chance to mmap()
- Grab ar_ptr->next prior to releasing its lock. */
- mstate prev = ar_ptr->next ? ar_ptr : 0;
- (void)mutex_unlock(&ar_ptr->mutex);
- ar_ptr = arena_get2(prev, bytes + 2*pagesz + MINSIZE, ar_ptr);
- if(ar_ptr) {
- p = _int_memalign(ar_ptr, pagesz, rounded_bytes);
- (void)mutex_unlock(&ar_ptr->mutex);
- }
}
} else
(void)mutex_unlock(&ar_ptr->mutex);
@@ -3225,22 +3194,10 @@ __libc_calloc(size_t n, size_t elem_size)
av == arena_for_chunk(mem2chunk(mem)));
if (mem == 0) {
- /* Maybe the failure is due to running out of mmapped areas. */
- if(av != &main_arena) {
+ av = get_another_arena (av, sz);
+ if (__builtin_expect(av != NULL, 1)) {
+ mem = _int_malloc(av, sz);
(void)mutex_unlock(&av->mutex);
- (void)mutex_lock(&main_arena.mutex);
- mem = _int_malloc(&main_arena, sz);
- (void)mutex_unlock(&main_arena.mutex);
- } else {
- /* ... or sbrk() has failed and there is still a chance to mmap()
- Grab av->next prior to releasing its lock. */
- mstate prev = av->next ? av : 0;
- (void)mutex_unlock(&av->mutex);
- av = arena_get2(prev, sz, av);
- if(av) {
- mem = _int_malloc(av, sz);
- (void)mutex_unlock(&av->mutex);
- }
}
if (mem == 0) return 0;
} else