From patchwork Wed Aug 21 14:40:58 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Weimer X-Patchwork-Id: 34225 Received: (qmail 48716 invoked by alias); 21 Aug 2019 14:41:03 -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 48707 invoked by uid 89); 21 Aug 2019 14:41:03 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-18.7 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, SPF_HELO_PASS autolearn=ham version=3.3.1 spammy=HX-Languages-Length:1943 X-HELO: mx1.redhat.com From: Florian Weimer To: libc-alpha@sourceware.org Subject: [PATCH] misc: Use allocate_once in getmntent Date: Wed, 21 Aug 2019 16:40:58 +0200 Message-ID: <8736huh98l.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.2 (gnu/linux) MIME-Version: 1.0 Both the buffer and struct mntent are now allocated on the heap. This results in a slight reduction of RSS usage. 2019-08-21 Florian Weimer * misc/mntent.c (struct mntent_buffer): Define. (mntent_buffer): Adjust type to void *. (allocate): Adjust for allocate_once. (deallocate): New function. (getmntent): Call allocate_once. Reviewed-by: Adhemerval Zanella diff --git a/misc/mntent.c b/misc/mntent.c index 980ea40967..8fae6064c6 100644 --- a/misc/mntent.c +++ b/misc/mntent.c @@ -18,36 +18,41 @@ #include #include -#include +#include + +struct mntent_buffer +{ + struct mntent m; + char buffer[4096]; +}; /* We don't want to allocate the static buffer all the time since it - is not always used (in fact, rather infrequently). Accept the - extra cost of a `malloc'. */ -libc_freeres_ptr (static char *getmntent_buffer); - -/* This is the size of the buffer. This is really big. */ -#define BUFFER_SIZE 4096 + is not always used (in fact, rather infrequently). */ +libc_freeres_ptr (static void *mntent_buffer); +static void * +allocate (void *closure) +{ + return malloc (sizeof (struct mntent_buffer)); +} static void -allocate (void) +deallocate (void *closure, void *ptr) { - getmntent_buffer = (char *) malloc (BUFFER_SIZE); + free (ptr); } - struct mntent * getmntent (FILE *stream) { - static struct mntent m; - __libc_once_define (static, once); - __libc_once (once, allocate); - - if (getmntent_buffer == NULL) + struct mntent_buffer *buffer = allocate_once (&mntent_buffer, + allocate, deallocate, NULL); + if (buffer == NULL) /* If no core is available we don't have a chance to run the program successfully and so returning NULL is an acceptable result. */ return NULL; - return __getmntent_r (stream, &m, getmntent_buffer, BUFFER_SIZE); + return __getmntent_r (stream, &buffer->m, + buffer->buffer, sizeof (buffer->buffer)); }