From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f72.google.com (mail-it0-f72.google.com [209.85.214.72]) by kanga.kvack.org (Postfix) with ESMTP id 58B076B025F for ; Mon, 14 Aug 2017 10:46:06 -0400 (EDT) Received: by mail-it0-f72.google.com with SMTP id j124so108403624itj.12 for ; Mon, 14 Aug 2017 07:46:06 -0700 (PDT) Received: from userp1040.oracle.com (userp1040.oracle.com. [156.151.31.81]) by mx.google.com with ESMTPS id w136si5577816ita.92.2017.08.14.07.46.05 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 14 Aug 2017 07:46:05 -0700 (PDT) Date: Mon, 14 Aug 2017 17:45:40 +0300 From: Dan Carpenter Subject: Re: [PATCH 1/2] kmemleak: Delete an error message for a failed memory allocation in two functions Message-ID: <20170814144540.q2ib32ge2ekm7irl@mwanda> References: <301bc8c9-d9f6-87be-ce1d-dc614e82b45b@users.sourceforge.net> <986426ab-4ca9-ee56-9712-d06c25a2ed1a@users.sourceforge.net> <20170814111430.lskrrg3fygpnyx6v@armageddon.cambridge.arm.com> <20170814130220.q5w4fsbngphniqzc@mwanda> <20170814143804.d66iibto5dacvifk@armageddon.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170814143804.d66iibto5dacvifk@armageddon.cambridge.arm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Catalin Marinas Cc: SF Markus Elfring , linux-mm@kvack.org, LKML , kernel-janitors@vger.kernel.org On Mon, Aug 14, 2017 at 03:38:04PM +0100, Catalin Marinas wrote: > On Mon, Aug 14, 2017 at 04:02:21PM +0300, Dan Carpenter wrote: > > On Mon, Aug 14, 2017 at 12:14:32PM +0100, Catalin Marinas wrote: > > > On Mon, Aug 14, 2017 at 11:35:02AM +0200, SF Markus Elfring wrote: > > > > From: Markus Elfring > > > > Date: Mon, 14 Aug 2017 10:50:22 +0200 > > > > > > > > Omit an extra message for a memory allocation failure in these functions. > > > > > > > > This issue was detected by using the Coccinelle software. > > > > > > > > Signed-off-by: Markus Elfring > > > > --- > > > > mm/kmemleak.c | 5 +---- > > > > 1 file changed, 1 insertion(+), 4 deletions(-) > > > > > > > > diff --git a/mm/kmemleak.c b/mm/kmemleak.c > > > > index 7780cd83a495..c6c798d90b2e 100644 > > > > --- a/mm/kmemleak.c > > > > +++ b/mm/kmemleak.c > > > > @@ -555,7 +555,6 @@ 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(); > > > > > > I don't really get what this patch is trying to achieve. Given that > > > kmemleak will be disabled after this, I'd rather know why it happened. > > > > kmem_cache_alloc() will generate a stack trace and a bunch of more > > useful information if it fails. The allocation isn't likely to fail, > > but if it does you will know. The extra message is just wasting RAM. > > Currently kmemleak uses __GFP_NOWARN for its own metadata allocation, so > we wouldn't see the sl*b warnings. I don't fully remember why I went for > this gfp flag, probably not to interfere with other messages printed by > the allocator (kmemleak_alloc is called from within sl*b). > > I'm fine to drop __GFP_NOWARN and remove those extra messages. > Ah. I considered that, but didn't see a NOWARN in the diff and was too lazy to check the code. Probably I would just leave it as-is. regards, dan carpenter -- 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