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=0.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, TRACKER_ID autolearn=unavailable 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 0A1C3C282CE for ; Mon, 11 Feb 2019 15:41:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CF80E222A7 for ; Mon, 11 Feb 2019 15:41:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=stwm.de header.i=@stwm.de header.b="OxNU3yDc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387905AbfBKPla (ORCPT ); Mon, 11 Feb 2019 10:41:30 -0500 Received: from dresden.studentenwerk.mhn.de ([141.84.225.229]:58566 "EHLO email.studentenwerk.mhn.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387599AbfBKPla (ORCPT ); Mon, 11 Feb 2019 10:41:30 -0500 X-Greylist: delayed 414 seconds by postgrey-1.27 at vger.kernel.org; Mon, 11 Feb 2019 10:41:29 EST Received: from mailhub.studentenwerk.mhn.de (mailhub.studentenwerk.mhn.de [127.0.0.1]) by email.studentenwerk.mhn.de (Postfix) with ESMTP id 43yqbH0G0LzRhS4; Mon, 11 Feb 2019 16:34:35 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=stwm.de; s=stwm-20170627; t=1549899275; bh=19nuiacV19xmkpfgKbv+iH3PJpuaptko+I7zTJ2ft7c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OxNU3yDcaN3H1PrQOaftLhUJN35jnqGVr7zf3DIfQaerJ+PBnG72ioCK/o22gUoGI mqCrhncgFmEv6eUGE8+1pv04CGWidvzpOwV+a970M56vbCBKRUaw7cYKbEmON9/E7b wHPpgVbBgEEM6D81PEOtYaIUFC8KT0j92eqy5x04M1pNN+BdsQ3KLjdsl40KsMY7Vm fxZXM6reSNRnSTFbLdun0Nd0DqFQs9vvZd6Lfo0xN2SO2ZMF/zwWWETX5+Q0Hcjz81 3SxMOhUGKQZMCBMTKR7OEsh8oroJ6yW2SNnqZv2xs91Nv6oPCK3CYJXIwi90YYDCJY U0p2ouScLPNdQ== From: Wolfgang Walter To: Jan Kara Cc: Dave Chinner , Roman Gushchin , Michal Hocko , Chris Mason , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, akpm@linux-foundation.org, vdavydov.dev@gmail.com Subject: Re: [PATCH 1/2] Revert "mm: don't reclaim inodes with many attached pages" Date: Mon, 11 Feb 2019 16:34:34 +0100 Message-ID: <2582452.8YSf1DXvRS@stwm.de> User-Agent: KMail/4.14.3 (Linux/4.18.12-041812-generic; KDE/4.14.13; x86_64; ; ) In-Reply-To: <20190207102750.GA4570@quack2.suse.cz> References: <20190130041707.27750-1-david@fromorbit.com> <20190131221904.GL4205@dastard> <20190207102750.GA4570@quack2.suse.cz> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="iso-8859-1" Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Am Donnerstag, 7. Februar 2019, 11:27:50 schrieb Jan Kara: > On Fri 01-02-19 09:19:04, Dave Chinner wrote: > > Maybe for memcgs, but that's exactly the oppose of what we want to > > do for global caches (e.g. filesystem metadata caches). We need to > > make sure that a single, heavily pressured cache doesn't evict smal= l > > caches that lower pressure but are equally important for > > performance. > >=20 > > e.g. I've noticed recently a significant increase in RMW cycles in > > XFS inode cache writeback during various benchmarks. It hasn't > > affected performance because the machine has IO and CPU to burn, bu= t > > on slower machines and storage, it will have a major impact. >=20 > Just as a data point, our performance testing infrastructure has bise= cted > down to the commits discussed in this thread as the cause of about 40= % > regression in XFS file delete performance in bonnie++ benchmark. We also bisected our big IO-performance problem of an imap-server (star= ting=20 with 4.19.3) down to =09mm: don't reclaim inodes with many attached pages =09commit a76cf1a474d7dbcd9336b5f5afb0162baa142cf0 upstream. On other servers the filesystems sometimes seems to hang for 10 seconds= and=20 more. We also see a performance regression compared to 4.14 even with this pa= tch=20 reverted, but much less dramatic. Now I saw this thread and I'll try to revert 172b06c32b949759fe6313abec514bc4f15014f4 and see if this helps. Regards, --=20 Wolfgang Walter Studentenwerk M=FCnchen Anstalt des =F6ffentlichen Rechts