From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?B?546L6LSH?= Subject: Re: [PATCH 4/4] numa: introduce numa cling feature Date: Mon, 22 Jul 2019 11:44:48 +0800 Message-ID: References: <209d247e-c1b2-3235-2722-dd7c1f896483@linux.alibaba.com> <60b59306-5e36-e587-9145-e90657daec41@linux.alibaba.com> <9a440936-1e5d-d3bb-c795-ef6f9839a021@linux.alibaba.com> <20190711142728.GF3402@hirez.programming.kicks-ass.net> <82f42063-ce51-dd34-ba95-5b32ee733de7@linux.alibaba.com> <20190712075318.GM3402@hirez.programming.kicks-ass.net> <0a5066be-ac10-5dce-c0a6-408725bc0784@linux.alibaba.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <0a5066be-ac10-5dce-c0a6-408725bc0784@linux.alibaba.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="utf-8" To: Peter Zijlstra Cc: hannes@cmpxchg.org, mhocko@kernel.org, vdavydov.dev@gmail.com, Ingo Molnar , linux-kernel@vger.kernel.org, linux-mm@kvack.org, mcgrof@kernel.org, keescook@chromium.org, linux-fsdevel@vger.kernel.org, cgroups@vger.kernel.org, Mel Gorman , riel@surriel.com On 2019/7/12 δΈ‹εˆ4:58, ηŽ‹θ΄‡ wrote: [snip] > > I see, we should not override the decision of select_idle_sibling(). > > Actually the original design we try to achieve is: > > let wake affine select the target > try find idle sibling of target > if got one > pick it > else if task cling to prev > pick prev > > That is to consider wake affine superior to numa cling. > > But after rethinking maybe this is not necessary, since numa cling is > also some kind of strong wake affine hint, actually maybe even a better > one to filter out the bad cases. > > I'll try change @target instead and give a retest then. We now leave select_idle_sibling() untouched, instead prevent numa swap with task cling to dst, and stop wake affine when curr & prev cpu are on different node and wakee cling to prev. Retesting show a even better results, benchmark like dbench also show 1%~5% improvement, not stable but always improved now :-) Regards, Michael Wang > > Regards, > Michael Wang >