From patchwork Tue Nov 14 16:34:24 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Weimer X-Patchwork-Id: 24238 Received: (qmail 42690 invoked by alias); 14 Nov 2017 16:34:28 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 42242 invoked by uid 89); 14 Nov 2017 16:34:28 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-26.7 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_SHORT, KB_WAM_FROM_NAME_SINGLEWORD, RP_MATCHES_RCVD, SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=Obtain X-HELO: mx1.redhat.com Date: Tue, 14 Nov 2017 17:34:24 +0100 To: libc-alpha@sourceware.org Subject: [PATCH] malloc: Add missing arena lock in malloc_info [BZ #22408] User-Agent: Heirloom mailx 12.5 7/5/10 MIME-Version: 1.0 Message-Id: <20171114163424.79757422BD2CC@oldenburg.str.redhat.com> From: fweimer@redhat.com (Florian Weimer) Obtain the size information while the arena lock is acquired, and only print it later. 2017-11-14 Florian Weimer [BZ #22408] * malloc/malloc.c (__malloc_info): Obtain arena heap statistics under the per-arena lock. * malloc/Makefile (tests): Add tst-malloc_info. (tst-malloc_info): Link with libpthread. * malloc/tst-malloc_info.c: New file. diff --git a/malloc/Makefile b/malloc/Makefile index 7ae3d825b9..17936fc04d 100644 --- a/malloc/Makefile +++ b/malloc/Makefile @@ -35,6 +35,7 @@ tests := mallocbug tst-malloc tst-valloc tst-calloc tst-obstack \ tst-interpose-thread \ tst-alloc_buffer \ tst-malloc-tcache-leak \ + tst-malloc_info \ tests-static := \ tst-interpose-static-nothread \ @@ -246,3 +247,4 @@ $(objpfx)tst-dynarray-fail-mem.out: $(objpfx)tst-dynarray-fail.out $(evaluate-test) $(objpfx)tst-malloc-tcache-leak: $(shared-thread-library) +$(objpfx)tst-malloc_info: $(shared-thread-library) diff --git a/malloc/malloc.c b/malloc/malloc.c index f94d51cca1..0494e8c39f 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -5455,6 +5455,15 @@ __malloc_info (int options, FILE *fp) avail += sizes[NFASTBINS - 1 + i].total; } + size_t heap_size = 0; + size_t heap_mprotect_size = 0; + if (ar_ptr != &main_arena) + { + heap_info *heap = heap_for_ptr (top (ar_ptr)); + heap_size = heap->size; + heap_mprotect_size = heap->mprotect_size; + } + __libc_lock_unlock (ar_ptr->mutex); total_nfastblocks += nfastblocks; @@ -5488,13 +5497,12 @@ __malloc_info (int options, FILE *fp) if (ar_ptr != &main_arena) { - heap_info *heap = heap_for_ptr (top (ar_ptr)); fprintf (fp, "\n" "\n", - heap->size, heap->mprotect_size); - total_aspace += heap->size; - total_aspace_mprotect += heap->mprotect_size; + heap_size, heap_mprotect_size); + total_aspace += heap_size; + total_aspace_mprotect += heap_mprotect_size; } else { diff --git a/malloc/tst-malloc_info.c b/malloc/tst-malloc_info.c new file mode 100644 index 0000000000..44d460b29c --- /dev/null +++ b/malloc/tst-malloc_info.c @@ -0,0 +1,101 @@ +/* Smoke test for malloc_info + Copyright (C) 2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +/* The purpose of this test is to provide a quick way to run + malloc_info in a multi-threaded process. */ + +#include +#include +#include +#include +#include + +/* This barrier is used to have the main thread wait until the helper + threads have performed their allocations. */ +static pthread_barrier_t barrier; + +enum + { + /* Number of threads performing allocations. */ + thread_count = 4, + + /* Amount of memory allocation per thread. This should be large + enough to cause the allocation of multiple heaps per arena. */ + per_thread_allocations + = sizeof (void *) == 4 ? 16 * 1024 * 1024 : 128 * 1024 * 1024, + }; + +static void * +allocation_thread_function (void *closure) +{ + struct list + { + struct list *next; + long dummy[4]; + }; + + struct list *head = NULL; + size_t allocated = 0; + while (allocated < per_thread_allocations) + { + struct list *new_head = xmalloc (sizeof (*new_head)); + allocated += sizeof (*new_head); + new_head->next = head; + head = new_head; + } + + xpthread_barrier_wait (&barrier); + + /* Main thread prints first statistics here. */ + + xpthread_barrier_wait (&barrier); + + while (head != NULL) + { + struct list *next_head = head->next; + free (head); + head = next_head; + } + + return NULL; +} + +static int +do_test (void) +{ + xpthread_barrier_init (&barrier, NULL, thread_count + 1); + + pthread_t threads[thread_count]; + for (size_t i = 0; i < array_length (threads); ++i) + threads[i] = xpthread_create (NULL, allocation_thread_function, NULL); + + xpthread_barrier_wait (&barrier); + puts ("info: After allocation:"); + malloc_info (0, stdout); + + xpthread_barrier_wait (&barrier); + for (size_t i = 0; i < array_length (threads); ++i) + xpthread_join (threads[i]); + + puts ("\ninfo: After deallocation:"); + malloc_info (0, stdout); + + return 0; +} + +#include