From c78ab0947353c8f46d23857ebf3fb4a70ed581d9 Mon Sep 17 00:00:00 2001 From: Siddhesh Poyarekar Date: Fri, 7 Sep 2012 14:39:52 +0530 Subject: [PATCH] Cleanup code duplication in malloc on fallback to use another arena Break the fallback code to try another arena into a separate function for readability. --- ChangeLog | 11 +++++++ malloc/arena.c | 21 ++++++++++++ malloc/malloc.c | 86 +++++++------------------------------------------ 3 files changed, 43 insertions(+), 75 deletions(-) diff --git a/ChangeLog b/ChangeLog index 3859bf8ba7..a1e16e628a 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,14 @@ +2012-09-07 Siddhesh Poyarekar + + * malloc/arena.c (arena_get_retry): New function that gets + another arena for the caller to try its request on. + * malloc/malloc.c (__libc_malloc): Use get_another_arena if the + current arena cannot fulfill the request. + (__libc_memalign): Likewise. + (__libc_memalign): Likewise. + (__libc_pvalloc): Likewise. + (__libc_calloc): Likewise. + 2012-09-05 John Tobey [BZ #13542] diff --git a/malloc/arena.c b/malloc/arena.c index b893baeb43..97c0b909cc 100644 --- a/malloc/arena.c +++ b/malloc/arena.c @@ -917,6 +917,27 @@ arena_get2(mstate a_tsd, size_t size, mstate avoid_arena) return a; } +/* 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 of the other arenas. */ +static mstate +arena_get_retry (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; +} + #ifdef PER_THREAD static void __attribute__ ((section ("__libc_thread_freeres_fn"))) arena_thread_freeres (void) diff --git a/malloc/malloc.c b/malloc/malloc.c index 13b19bb15b..ca1d73f875 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -2858,23 +2858,10 @@ __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 = arena_get_retry(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 +3025,10 @@ __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 = arena_get_retry (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 +3062,10 @@ __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 = arena_get_retry (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 +3097,10 @@ __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 = arena_get_retry (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 +3173,10 @@ __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 = arena_get_retry (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