From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Shi Subject: Re: [PATCH v9 07/20] mm/lru: introduce TestClearPageLRU Date: Wed, 4 Mar 2020 15:06:48 +0800 Message-ID: <6d155f79-8ba2-b322-4e92-311e7be98f79@linux.alibaba.com> References: <1583146830-169516-1-git-send-email-alex.shi@linux.alibaba.com> <1583146830-169516-8-git-send-email-alex.shi@linux.alibaba.com> <20200302141144.b30abe0d89306fd387e13a92@linux-foundation.org> <9cacdc21-9c1f-2a17-05cb-e9cf2959cef5@linux.alibaba.com> <20200303164659.b3a30ab9d68c9ed82299a29c@linux-foundation.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200303164659.b3a30ab9d68c9ed82299a29c-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="utf-8" To: Andrew Morton Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, mgorman-3eNAlZScCAx27rWaFMvyedHuzzzSOjJt@public.gmane.org, tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, hughd-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, khlebnikov-XoJtRXgx1JseBXzfvpsJ4g@public.gmane.org, daniel.m.jordan-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org, yang.shi-KPsoFbNs7GizrGE5bRqYAgC/G2K4zDHf@public.gmane.org, willy-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org, lkp-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, Michal Hocko , Vladimir Davydov , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Rong Chen 在 2020/3/4 上午8:46, Andrew Morton 写道: > > Well, any difference would be small and the numbers did get a bit > lower, albeit probably within the margin of error. > > But you know, if someone were to send a patch which micro-optimized > some code by replacing 'TestClearXXX()' with `if PageXXX() > ClearPageXXX()', I would happily merge it! > > Is this change essential to the overall patchset? If not, I'd be > inclined to skip it? > Hi Andrew, Thanks a lot for comments! Yes, this patch is essential for all next. Consider the normal memory testing would focus on user page, that probabably with PageLRU. Fengguang's vm-scalibicase-small-allocs which used a lots vm_area_struct slab, which may got some impact. 0day/Cheng Rong is working on the test. In my roughly testing, it may drop 5% on my 96threads/394GB machine. Thanks Alex