From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ot0-f198.google.com (mail-ot0-f198.google.com [74.125.82.198]) by kanga.kvack.org (Postfix) with ESMTP id 7EA7E6B026D for ; Thu, 23 Nov 2017 05:43:30 -0500 (EST) Received: by mail-ot0-f198.google.com with SMTP id r55so9883716otc.23 for ; Thu, 23 Nov 2017 02:43:30 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id p1si8119305otp.471.2017.11.23.02.43.29 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 23 Nov 2017 02:43:29 -0800 (PST) Subject: Re: [PATCH] mm,vmscan: Mark register_shrinker() as __must_check References: <201711220709.JJJ12483.MtFOOJFHOLQSVF@I-love.SAKURA.ne.jp> <201711221953.IDJ12440.OQLtFVOJFMSHFO@I-love.SAKURA.ne.jp> <20171122203907.GI4094@dastard> <201711231534.BBI34381.tJOOHLQMOFVFSF@I-love.SAKURA.ne.jp> <2178e42e-9600-4f9a-4b91-22d2ba6f98c0@redhat.com> <201711231856.CFH69777.FtOSJFMQHLOVFO@I-love.SAKURA.ne.jp> From: Paolo Bonzini Message-ID: <83429cb3-4962-4a16-793e-42483a843c75@redhat.com> Date: Thu, 23 Nov 2017 11:43:21 +0100 MIME-Version: 1.0 In-Reply-To: <201711231856.CFH69777.FtOSJFMQHLOVFO@I-love.SAKURA.ne.jp> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Tetsuo Handa Cc: david@fromorbit.com, mhocko@kernel.org, akpm@linux-foundation.org, glauber@scylladb.com, linux-mm@kvack.org, viro@zeniv.linux.org.uk, jack@suse.com, airlied@linux.ie, alexander.deucher@amd.com, shli@fb.com, snitzer@redhat.com On 23/11/2017 10:56, Tetsuo Handa wrote: > Paolo Bonzini wrote: >> On 23/11/2017 07:34, Tetsuo Handa wrote: >>>> Just fix the numa aware shrinkers, as they are the only ones that >>>> will have this problem. There are only 6 of them, and only the 3 >>>> that existed at the time that register_shrinker() was changed to >>>> return an error fail to check for an error. i.e. the superblock >>>> shrinker, the XFS dquot shrinker and the XFS buffer cache shrinker. >>> >>> You are assuming the "too small to fail" memory-allocation rule >>> by ignoring that this problem is caused by fault injection. >> >> Fault injection should also obey the too small to fail rule, at least by >> default. > > Pardon? Most allocation requests in the kernel are <= 32KB. > Such change makes fault injection useless. ;-) But if these calls are "too small to fail", you are injecting a fault on something that cannot fail anyway. Unless you're aiming at removing "too small to fail", then I understand. Paolo -- 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