From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steffen Prohaska Subject: [PATCH v4 2/4] Introduce GIT_MMAP_LIMIT to allow testing expected mmap size Date: Fri, 22 Aug 2014 16:01:21 +0200 Message-ID: <1408716083-9093-3-git-send-email-prohaska@zib.de> References: <1408716083-9093-1-git-send-email-prohaska@zib.de> Cc: git@vger.kernel.org, peff@peff.net, pclouds@gmail.com, john@keeping.me.uk, schacon@gmail.com, Steffen Prohaska To: Junio C Hamano X-From: git-owner@vger.kernel.org Fri Aug 22 16:03:39 2014 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XKpRD-0002Js-G0 for gcvg-git-2@plane.gmane.org; Fri, 22 Aug 2014 16:03:31 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932499AbaHVODZ (ORCPT ); Fri, 22 Aug 2014 10:03:25 -0400 Received: from mailer.zib.de ([130.73.108.11]:33655 "EHLO mailer.zib.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932158AbaHVODX (ORCPT ); Fri, 22 Aug 2014 10:03:23 -0400 Received: from mailsrv2.zib.de (mailsrv2.zib.de [130.73.108.14]) by mailer.zib.de (8.14.5/8.14.5) with ESMTP id s7ME1wEX009786; Fri, 22 Aug 2014 16:01:58 +0200 (CEST) Received: from vss6.zib.de (vss6.zib.de [130.73.69.7]) by mailsrv2.zib.de (8.14.5/8.14.5) with ESMTP id s7ME1vrT009676; Fri, 22 Aug 2014 16:01:58 +0200 (CEST) X-Mailer: git-send-email 2.0.1.448.g1eafa63 In-Reply-To: <1408716083-9093-1-git-send-email-prohaska@zib.de> X-Miltered: at mailer.zib.de with ID 53F74D56.002 by Joe's j-chkmail (http : // j-chkmail dot ensmp dot fr)! X-j-chkmail-Enveloppe: 53F74D56.002 from mailsrv2.zib.de/mailsrv2.zib.de/null/mailsrv2.zib.de/ X-j-chkmail-Score: MSGID : 53F74D56.002 on mailer.zib.de : j-chkmail score : . : R=. U=. O=. B=0.000 -> S=0.000 X-j-chkmail-Status: Ham Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Similar to testing expectations about malloc with GIT_ALLOC_LIMIT (see commit d41489), it can be useful to test expectations about mmap. This introduces a new environment variable GIT_MMAP_LIMIT to limit the largest allowed mmap length (in KB). xmmap() is modified to check the limit. Together with GIT_ALLOC_LIMIT tests can now easily confirm expectations about memory consumption. GIT_MMAP_LIMIT will be used in the next commit to test that data will be streamed to an external filter without mmaping the entire file. [commit d41489]: d41489a6424308dc9a0409bc2f6845aa08bd4f7d Add more large blob test cases Signed-off-by: Steffen Prohaska --- sha1_file.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/sha1_file.c b/sha1_file.c index 00c07f2..603673b 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -663,10 +663,25 @@ void release_pack_memory(size_t need) ; /* nothing */ } +static void mmap_limit_check(size_t length) +{ + static ssize_t limit = -1; + if (limit == -1) { + const char *env = getenv("GIT_MMAP_LIMIT"); + limit = env ? atol(env) * 1024 : 0; + } + if (limit && length > limit) + die("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX, + (uintmax_t)length, (uintmax_t)limit); +} + void *xmmap(void *start, size_t length, int prot, int flags, int fd, off_t offset) { - void *ret = mmap(start, length, prot, flags, fd, offset); + void *ret; + + mmap_limit_check(length); + ret = mmap(start, length, prot, flags, fd, offset); if (ret == MAP_FAILED) { if (!length) return NULL; -- 2.1.0.6.gb452461