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=-7.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 BCB22C433E0 for ; Tue, 29 Dec 2020 01:10:48 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4E92F2084D for ; Tue, 29 Dec 2020 01:10:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4E92F2084D 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 6D3BE8D0022; Mon, 28 Dec 2020 20:10:47 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 684F68D0018; Mon, 28 Dec 2020 20:10:47 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 574B38D0022; Mon, 28 Dec 2020 20:10:47 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0126.hostedemail.com [216.40.44.126]) by kanga.kvack.org (Postfix) with ESMTP id 3EF238D0018 for ; Mon, 28 Dec 2020 20:10:47 -0500 (EST) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id F0BAE824999B for ; Tue, 29 Dec 2020 01:10:46 +0000 (UTC) X-FDA: 77644540092.26.mark87_4f16fe827498 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin26.hostedemail.com (Postfix) with ESMTP id D5FB31804B655 for ; Tue, 29 Dec 2020 01:10:46 +0000 (UTC) X-HE-Tag: mark87_4f16fe827498 X-Filterd-Recvd-Size: 3887 Received: from mail-qt1-f172.google.com (mail-qt1-f172.google.com [209.85.160.172]) by imf45.hostedemail.com (Postfix) with ESMTP for ; Tue, 29 Dec 2020 01:10:46 +0000 (UTC) Received: by mail-qt1-f172.google.com with SMTP id z3so8061464qtw.9 for ; Mon, 28 Dec 2020 17:10:46 -0800 (PST) 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:content-transfer-encoding; bh=jTblGVy12KttnCpCdJ35MVlE2TQ4BSno7et+Y7H5Mfg=; b=j9heRQVh+jzLspOpfU+dZ9v5/6Yj4OgxBhU4m/3bCIK52i36ADCx9E3y8Cb+Za1Xbk VvFFevVP0fTjYWjeOVYlmirhCGyXErQlr5EiB7WkWvngFsLeTQ6iNO7txJquQqC7W4zA pahrsdYaVf2uocS5iyV4Fs7SsHVusLSg5u/rSP8nuW3cvCtsXuhHXlC1vXcDb/K/hIEj YsLDodEMgkmahlL1SL0a3ti/iUtKR4c03lVRnc/7kc9wxIqd0XqK1h8OScYsBFLBSJiu F6oY07OLzpdrlpHOIufpNKb70jQ23lGOtq31TydflOmFr2FHdqDu1nu+BPlQwOXGH0lW m5FQ== 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=jTblGVy12KttnCpCdJ35MVlE2TQ4BSno7et+Y7H5Mfg=; b=oNNx777zl8+/RvxwSEC0mhrsibL0W7xS56qBw+1l9I8vyI5XUxhg1eGS3TR8UYzWHq HyIvHCXKwuYpn3a2JfQOknfbPcvK8lp4AOyuddUaoxiof9DHNbcdQxkfeI6RqjEr4UjJ pRcbQbZltFQ1bicukExbYAdh+TGdb8SUiMDffrCip0Z8XKI2A0EH8wcJpBy76ln3GsHi /NcimPvAnj6Ta9xHL1p3T5Ti6JKiH/cFn6BQw8QxwzZbpEqjL1oeNiARq29yjYaDXEaM KFR0T35m3F/xxa5YhxpJR5bHgLbgb+qfeoq35ULNxpWa6EoWAyObvbD8p0gfm9jYH6Bc hEsQ== X-Gm-Message-State: AOAM532yqCDOw/On87TdEff8VCUQjo0zKA9TW/mPEiFw71pQT9OFdNGX JLn3rKbGVnbKSzWDhC+0LumrM7oPtIA5tihntzU= X-Google-Smtp-Source: ABdhPJytjvaYrurpuqAHSjl12rETbCix8KlKt/uoQw+UZHZHfkmwyxpaTa/cAiCJAv+urriOgPavUVfxHZwHLlT5RU8= X-Received: by 2002:ac8:58d1:: with SMTP id u17mr46735628qta.158.1609204245809; Mon, 28 Dec 2020 17:10:45 -0800 (PST) MIME-Version: 1.0 References: <20201228130853.1871516-1-jannh@google.com> In-Reply-To: <20201228130853.1871516-1-jannh@google.com> From: Joonsoo Kim Date: Tue, 29 Dec 2020 10:10:34 +0900 Message-ID: Subject: Re: [PATCH] mm, slub: Consider rest of partial list if acquire_slab() fails To: Jann Horn Cc: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Linux Memory Management List , LKML 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: 2020=EB=85=84 12=EC=9B=94 28=EC=9D=BC (=EC=9B=94) =EC=98=A4=ED=9B=84 10:10,= Jann Horn =EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84=B1: > > acquire_slab() fails if there is contention on the freelist of the page > (probably because some other CPU is concurrently freeing an object from t= he > page). In that case, it might make sense to look for a different page > (since there might be more remote frees to the page from other CPUs, and = we > don't want contention on struct page). > > However, the current code accidentally stops looking at the partial list > completely in that case. Especially on kernels without CONFIG_NUMA set, > this means that get_partial() fails and new_slab_objects() falls back to > new_slab(), allocating new pages. This could lead to an unnecessary > increase in memory fragmentation. > > Fixes: 7ced37197196 ("slub: Acquire_slab() avoid loop") > Signed-off-by: Jann Horn Acked-by: Joonsoo Kim Thanks.