From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f198.google.com (mail-qk0-f198.google.com [209.85.220.198]) by kanga.kvack.org (Postfix) with ESMTP id C91B4440941 for ; Fri, 14 Jul 2017 19:50:36 -0400 (EDT) Received: by mail-qk0-f198.google.com with SMTP id a195so47192275qkb.13 for ; Fri, 14 Jul 2017 16:50:36 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id 35si9077795qtr.317.2017.07.14.16.50.35 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 14 Jul 2017 16:50:35 -0700 (PDT) From: shuwang@redhat.com Subject: [PATCH v2] kmemleak: add oom= runtime parameter Date: Sat, 15 Jul 2017 07:50:24 +0800 Message-Id: <1500076224-13404-1-git-send-email-shuwang@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: catalin.marinas@arm.com, corbet@lwn.net Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, shuwang@redhat.com, liwang@redhat.com, chuhu@redhat.com 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..b5cb2c6 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) == 0) + kmemleak_oom_disable = false; + else if (strncmp(buf, "oom=disable", 11) == 0) + kmemleak_oom_disable = true; else ret = -EINVAL; -- 2.5.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org