From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753758AbdGNJjk (ORCPT ); Fri, 14 Jul 2017 05:39:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40020 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753623AbdGNJjg (ORCPT ); Fri, 14 Jul 2017 05:39:36 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com A9C28158A9F Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=shuwang@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com A9C28158A9F From: shuwang@redhat.com To: catalin.marinas@arm.com, corbet@lwn.net Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, liwang@redhat.com, shuwang@redhat.com, chuhu@redhat.com Subject: [PATCH] kmemleak: add oom= runtime parameter Date: Fri, 14 Jul 2017 17:39:20 +0800 Message-Id: <1500025160-25504-1-git-send-email-shuwang@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Fri, 14 Jul 2017 09:39:30 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Shu Wang When running memory stress tests, kmemleak could be easily disabled in function create_object as system is out of memory and kmemleak failed to alloc from object_cache. Since there's no way to enable kmemleak after it's off, simply ignore the object_cache alloc failure will just loses track of some memory objects, but could increase the usability of kmemleak under memory stress. The default action for oom is still disable kmemleak, echo oom=ignore > /sys/kernel/debug/kmemleak can change to action to ignore oom. Signed-off-by: Shu Wang --- Documentation/dev-tools/kmemleak.rst | 5 +++++ mm/kmemleak.c | 10 +++++++++- 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/Documentation/dev-tools/kmemleak.rst b/Documentation/dev-tools/kmemleak.rst index cb88626..3013809 100644 --- a/Documentation/dev-tools/kmemleak.rst +++ b/Documentation/dev-tools/kmemleak.rst @@ -60,6 +60,11 @@ Memory scanning parameters can be modified at run-time by writing to the or free all kmemleak objects if kmemleak has been disabled. - dump= dump information about the object found at +- oom=disable + disable kmemleak after system out of memory (default) +- oom=ignore + do not disable kmemleak after system out of memory + (useful for memory stress test, but will lose some objects) Kmemleak can also be disabled at boot-time by passing ``kmemleak=off`` on the kernel command line. diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 7780cd8..a58080f 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -236,6 +236,9 @@ static DEFINE_MUTEX(scan_mutex); static int kmemleak_skip_disable; /* If there are leaks that can be reported */ static bool kmemleak_found_leaks; +/* If disable kmemleak after out of memory */ +static bool kmemleak_oom_disable = true; + /* * Early object allocation/freeing logging. Kmemleak is initialized after the @@ -556,7 +559,8 @@ static struct kmemleak_object *create_object(unsigned long ptr, size_t size, object = kmem_cache_alloc(object_cache, gfp_kmemleak_mask(gfp)); if (!object) { pr_warn("Cannot allocate a kmemleak_object structure\n"); - kmemleak_disable(); + if (kmemleak_oom_disable) + kmemleak_disable(); return NULL; } @@ -1888,6 +1892,10 @@ static ssize_t kmemleak_write(struct file *file, const char __user *user_buf, kmemleak_scan(); else if (strncmp(buf, "dump=", 5) == 0) ret = dump_str_object_info(buf + 5); + else if (strncmp(buf, "oom=ignore", 10)) + kmemleak_oom_disable = false; + else if (strncmp(buf, "oom=disable", 11)) + kmemleak_oom_disable = true; else ret = -EINVAL; -- 2.5.0