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=-9.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 9867AC4741F for ; Fri, 30 Oct 2020 18:34:12 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CF75120729 for ; Fri, 30 Oct 2020 18:34:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="IkdXBODJ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CF75120729 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id DD7D06B005C; Fri, 30 Oct 2020 14:34:10 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D88766B0062; Fri, 30 Oct 2020 14:34:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CC5B26B006C; Fri, 30 Oct 2020 14:34:10 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0242.hostedemail.com [216.40.44.242]) by kanga.kvack.org (Postfix) with ESMTP id A14376B005C for ; Fri, 30 Oct 2020 14:34:10 -0400 (EDT) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 425781EF2 for ; Fri, 30 Oct 2020 18:34:10 +0000 (UTC) X-FDA: 77429441460.18.twig55_4703a4927298 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin18.hostedemail.com (Postfix) with ESMTP id 20F34100ED0FC for ; Fri, 30 Oct 2020 18:34:10 +0000 (UTC) X-HE-Tag: twig55_4703a4927298 X-Filterd-Recvd-Size: 5269 Received: from mail-ed1-f67.google.com (mail-ed1-f67.google.com [209.85.208.67]) by imf36.hostedemail.com (Postfix) with ESMTP for ; Fri, 30 Oct 2020 18:34:09 +0000 (UTC) Received: by mail-ed1-f67.google.com with SMTP id w25so7687818edx.2 for ; Fri, 30 Oct 2020 11:34:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=UGg1dh3V0sVY8xG316RCn13ndhN0+H8ulqokbaS5n1U=; b=IkdXBODJEuUUuLLVn66wDZ8zSx76aeW2TXeeLw7vI4/A4m6IQ/gNaCpDQ07IgCAhgj +weZ8XKhuPqQe7lWDQYv3fYG9Mc8VGuarP43lfD88O3T9z5riCI7cfUyLikWy4Z+5kVD B0G06tXTyTv9gVluKIFENSPcOxRn9teFabczvJmSe1O4GEx0pePyQTKX4yPegUsTHBDW Msefif90Iv+bEnmg9860jXd7pHj+EddaiL54KW+KM25zOKtKCRCUjaGpbM9zEQ0vGfeX 8lHpxJ8y8T/HFaUQ/ekqB8+le9MjhtGdDRY7GYPrJzLAz6ZgiojGhPJSjps4JYAdbJwp tsyg== 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; bh=UGg1dh3V0sVY8xG316RCn13ndhN0+H8ulqokbaS5n1U=; b=IAO+tmnGKNe++sSJu717qpkAJ9Q7K92WYQUnOg0Z3jA2EWs1Xr904IfN3Kjt0M5Jvy pM/pcn03CAkaMNRUscPcof3GiOlC0f1PtIbJnC9kgPlkhHEnRDK4OLw9cI8ch7x8KVWf 2jpXbcyS3QDbrDPCbEqvzdesBdhFuiZ2nmteXhU9uXHrdJ/BDQrqUbOqnlRHmH4s/zA2 iBIlnWeo1z7WLrHkYcHGXavdYpb9i5PNyjLK5znp5ILmk5wJmkYmPfI/6v+fNMJpWbbb aEx3Q8qIAVSNeaEoRazQjFPiyeT/AhBMchY2WGMeeZR3LqyS2WE/uqoL2heTxCwlFvpY dwtA== X-Gm-Message-State: AOAM532n8S8+dGb5bHqCNmze79AL6Ib2cSuW6sygvz9YXkJulKtvQV7k S44E9777tfUAkJL1br0qtvleXCWLLasFGWo2ziY= X-Google-Smtp-Source: ABdhPJxAiP5WB7O1cuZKak34I/WKP+kggx6dIlMDsB0pELyn8xkOAEo6jECiB9YltACS8PoKARZdCTxWUIvNMLbwmic= X-Received: by 2002:a50:cc48:: with SMTP id n8mr3872441edi.137.1604082848406; Fri, 30 Oct 2020 11:34:08 -0700 (PDT) MIME-Version: 1.0 References: <20201029200435.3386066-1-zi.yan@sent.com> <20201030094308.GG1478@dhcp22.suse.cz> <6CAAB1FC-2B41-490B-A67A-93063629C19B@nvidia.com> <20201030133625.GJ1478@dhcp22.suse.cz> In-Reply-To: <20201030133625.GJ1478@dhcp22.suse.cz> From: Yang Shi Date: Fri, 30 Oct 2020 11:33:55 -0700 Message-ID: Subject: Re: [PATCH] mm/compaction: count pages and stop correctly during page isolation. To: Michal Hocko Cc: Zi Yan , Andrew Morton , Linux MM , Rik van Riel , Linux Kernel Mailing List , Vlastimil Babka Content-Type: text/plain; charset="UTF-8" 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: On Fri, Oct 30, 2020 at 6:36 AM Michal Hocko wrote: > > On Fri 30-10-20 08:20:50, Zi Yan wrote: > > On 30 Oct 2020, at 5:43, Michal Hocko wrote: > > > > > [Cc Vlastimil] > > > > > > On Thu 29-10-20 16:04:35, Zi Yan wrote: > > >> From: Zi Yan > > >> > > >> In isolate_migratepages_block, when cc->alloc_contig is true, we are > > >> able to isolate compound pages, nr_migratepages and nr_isolated did not > > >> count compound pages correctly, causing us to isolate more pages than we > > >> thought. Use thp_nr_pages to count pages. Otherwise, we might be trapped > > >> in too_many_isolated while loop, since the actual isolated pages can go > > >> up to COMPACT_CLUSTER_MAX*512=16384, where COMPACT_CLUSTER_MAX is 32, > > >> since we stop isolation after cc->nr_migratepages reaches to > > >> COMPACT_CLUSTER_MAX. > > >> > > >> In addition, after we fix the issue above, cc->nr_migratepages could > > >> never be equal to COMPACT_CLUSTER_MAX if compound pages are isolated, > > >> thus page isolation could not stop as we intended. Change the isolation > > >> stop condition to >=. > > >> > > >> Signed-off-by: Zi Yan > > >> --- > > >> mm/compaction.c | 8 ++++---- > > >> 1 file changed, 4 insertions(+), 4 deletions(-) > > >> > > >> diff --git a/mm/compaction.c b/mm/compaction.c > > >> index ee1f8439369e..0683a4999581 100644 > > >> --- a/mm/compaction.c > > >> +++ b/mm/compaction.c > > >> @@ -1012,8 +1012,8 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, > > >> > > >> isolate_success: > > >> list_add(&page->lru, &cc->migratepages); > > >> - cc->nr_migratepages++; > > >> - nr_isolated++; > > >> + cc->nr_migratepages += thp_nr_pages(page); > > >> + nr_isolated += thp_nr_pages(page); > > > > > > Does thp_nr_pages work for __PageMovable pages? > > > > Yes. It is the same as compound_nr() but compiled > > to 1 when THP is not enabled. > > I am sorry but I do not follow. First of all the implementation of the > two is different and also I was asking about __PageMovable which should > never be THP IIRC. Can they be compound though? I have the same question, can they be compound? If they can be compound, PageTransHuge() can't tell from THP and compound movable page, right? > > -- > Michal Hocko > SUSE Labs >