From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DB0E6C2BB55 for ; Thu, 16 Apr 2020 17:47:15 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5C5F52078B for ; Thu, 16 Apr 2020 17:47:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="PFngGB4T" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5C5F52078B Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 8DA638E00DA; Thu, 16 Apr 2020 13:47:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 863E48E00BC; Thu, 16 Apr 2020 13:47:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 72C098E00DA; Thu, 16 Apr 2020 13:47:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0009.hostedemail.com [216.40.44.9]) by kanga.kvack.org (Postfix) with ESMTP id 53A988E00BC for ; Thu, 16 Apr 2020 13:47:14 -0400 (EDT) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 188B6181AEF3C for ; Thu, 16 Apr 2020 17:47:14 +0000 (UTC) X-FDA: 76714449588.08.army45_22032d8d63561 X-HE-Tag: army45_22032d8d63561 X-Filterd-Recvd-Size: 7457 Received: from mail-lf1-f65.google.com (mail-lf1-f65.google.com [209.85.167.65]) by imf28.hostedemail.com (Postfix) with ESMTP for ; Thu, 16 Apr 2020 17:47:13 +0000 (UTC) Received: by mail-lf1-f65.google.com with SMTP id x23so6269655lfq.1 for ; Thu, 16 Apr 2020 10:47:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=DKQyd28J6klVlExdivV63IY2/jZ+2G6tdYSQ07jc4aE=; b=PFngGB4TWfc2/U4qmnsspqOKfmB4btthlE7TyKvPnUzzuBsT/y+E9ROWYkjgOkMKyB Bz/Po84HWCXDL+0TeFUvxFI9Ms9AxQtdQ+WrWwiVklnNi4L953PXrTO/JZYIMomM08Gf L7TlFz2/ALlwYkVHLzjCuSk23gG8hDu25gqx3KeP7uPK2DcqKI7bSJBOP/DMaLbhKBvS 7NTdWWuSyvp/vIZZx2O3VC6lu52ZSmL5tQwoE69Jy2qbuIUrdVIvMMQrgEcn8elB2t4L 5fMSjejeGC7ACFX5tL+7GKZnRJFYb2/dtjpdDSSkn2SaMzRGevQOTE3hFE54IbSVV90y /oeQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=DKQyd28J6klVlExdivV63IY2/jZ+2G6tdYSQ07jc4aE=; b=X6s/gze6mfDWdBPjnnp+5Kb5OZSuWt0E8SI2T21Ez+oGIu4bTXCWscETUPt44sZbPt OC62HLLmxK4SUy+vFF5cpVA/Tgme87sMMHpB2+t6NF6VdA8vJc5m0UFR+Ph1dX672wxE +VS1SQ9mkUH+F4PUvkOXcf9t3/wKfxh3ucmG4ZpYZ83m1CCBxRW2jmr9d6fwlV5cTcLA d5E3e/jXC8ymDoGQ8Fygd0pzAPh/lbxTNsGpocjo52kALRYvAIFzo7apSY/95mOYlgLI 9tfYSAoE2HFm9uOdtluZOLHg5/N9cyUhPzs7aeU5WUwvZv/4KhOg8e89zDkq0vAcGOeZ 6OLw== X-Gm-Message-State: AGi0PuYoGQUt+CKKrk5eBAfMt3qY6RRAUY0LwxuLz8w1BhKa0vStS7Tf FFUmym85sxIAPzmiqjlXDp4807GLSfNTvftIfNJDdQ== X-Google-Smtp-Source: APiQypJDp0D4AqUDwJHnySuxSP+B1kwEZrRgbzXx293VrEkAAtFPcqmlhTBHjBZ48dNkGluGECk4epotU8SiLM7h84Y= X-Received: by 2002:a19:c1d3:: with SMTP id r202mr6625545lff.216.1587059231673; Thu, 16 Apr 2020 10:47:11 -0700 (PDT) MIME-Version: 1.0 References: <1579143909-156105-1-git-send-email-alex.shi@linux.alibaba.com> <1579143909-156105-4-git-send-email-alex.shi@linux.alibaba.com> <20200116215222.GA64230@cmpxchg.org> <20200413180725.GA99267@cmpxchg.org> <8e7bf170-2bb5-f862-c12b-809f7f7d96cb@linux.alibaba.com> <20200414163114.GA136578@cmpxchg.org> <54af0662-cbb4-88c7-7eae-f969684025dd@linux.alibaba.com> <0bed9f1a-400d-d9a9-aeb4-de1dd9ccbb45@linux.alibaba.com> <20200416152830.GA195132@cmpxchg.org> In-Reply-To: <20200416152830.GA195132@cmpxchg.org> From: Shakeel Butt Date: Thu, 16 Apr 2020 10:47:00 -0700 Message-ID: Subject: Re: [PATCH v8 03/10] mm/lru: replace pgdat lru_lock with lruvec lock To: Johannes Weiner Cc: Alex Shi , Andrew Morton , Cgroups , LKML , Linux MM , Mel Gorman , Tejun Heo , Hugh Dickins , Konstantin Khlebnikov , Daniel Jordan , Yang Shi , Matthew Wilcox , Michal Hocko , Vladimir Davydov , Roman Gushchin , Chris Down , Thomas Gleixner , Vlastimil Babka , Qian Cai , Andrey Ryabinin , "Kirill A. Shutemov" , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Andrea Arcangeli , David Rientjes , "Aneesh Kumar K.V" , swkhack , "Potyra, Stefan" , Mike Rapoport , Stephen Rothwell , Colin Ian King , Jason Gunthorpe , Mauro Carvalho Chehab , Peng Fan , Nikolay Borisov , Ira Weiny , Kirill Tkhai , Yafang Shao , Wei Yang Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi Johannes & Alex, On Thu, Apr 16, 2020 at 8:28 AM Johannes Weiner wrote: > > Hi Alex, > > On Thu, Apr 16, 2020 at 04:01:20PM +0800, Alex Shi wrote: > > > > > > =E5=9C=A8 2020/4/15 =E4=B8=8B=E5=8D=889:42, Alex Shi =E5=86=99=E9=81=93= : > > > Hi Johannes, > > > > > > Thanks a lot for point out! > > > > > > Charging in __read_swap_cache_async would ask for 3 layers function a= rguments > > > pass, that would be a bit ugly. Compare to this, could we move out th= e > > > lru_cache add after commit_charge, like ksm copied pages? > > > > > > That give a bit extra non lru list time, but the page just only be us= ed only > > > after add_anon_rmap setting. Could it cause troubles? > > > > Hi Johannes & Andrew, > > > > Doing lru_cache_add_anon during swapin_readahead can give a very short = timing > > for possible page reclaiming for these few pages. > > > > If we delay these few pages lru adding till after the vm_fault target p= age > > get memcg charging(mem_cgroup_commit_charge) and activate, we could ski= p the > > mem_cgroup_try_charge/commit_charge/cancel_charge process in __read_swa= p_cache_async(). > > But the cost is maximum SWAP_RA_ORDER_CEILING number pages on each cpu = miss > > page reclaiming in a short time. On the other hand, save the target vm_= fault > > page from reclaiming before activate it during that time. > > The readahead pages surrounding the faulting page might never get > accessed and pile up to large amounts. Users can also trigger > non-faulting readahead with MADV_WILLNEED. > > So unfortunately, I don't see a way to keep these pages off the > LRU. They do need to be reclaimable, or they become a DoS vector. > > I'm currently preparing a small patch series to make swap ownership > tracking an integral part of memcg and change the swapin charging > sequence, then you don't have to worry about it. This will also > unblock Joonsoo's "workingset protection/detection on the anonymous > LRU list" patch series, since he is blocked on the same problem - he > needs the correct LRU available at swapin time to process refaults > correctly. Both of your patch series are already pretty large, they > shouldn't need to also deal with that. I think this would be a very good cleanup and will make the code much more readable. I totally agree to keep this separate from the other work. Please do CC me the series once it's ready. Now regarding the per-memcg LRU locks, Alex, did you get the chance to try the workload Hugh has provided? I was planning of posting Hugh's patch series but Hugh advised me to wait for your & Johannes's response since you both have already invested a lot of time in your series and I do want to see how Johannes's TestClearPageLRU() idea will look like, so, I will hold off for now. thanks, Shakeel