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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 6E742C433EF for ; Mon, 9 Sep 2019 12:21:14 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3B3F42067B for ; Mon, 9 Sep 2019 12:21:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3B3F42067B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B6B4F6B0007; Mon, 9 Sep 2019 08:21:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B1BC76B0008; Mon, 9 Sep 2019 08:21:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A0AE26B000A; Mon, 9 Sep 2019 08:21:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0221.hostedemail.com [216.40.44.221]) by kanga.kvack.org (Postfix) with ESMTP id 837F46B0007 for ; Mon, 9 Sep 2019 08:21:13 -0400 (EDT) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id 27864180AD801 for ; Mon, 9 Sep 2019 12:21:13 +0000 (UTC) X-FDA: 75915292026.03.spot38_61e345a00695f X-HE-Tag: spot38_61e345a00695f X-Filterd-Recvd-Size: 3215 Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) by imf45.hostedemail.com (Postfix) with ESMTP for ; Mon, 9 Sep 2019 12:21:12 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 5AC8DAF38; Mon, 9 Sep 2019 12:21:11 +0000 (UTC) Subject: Re: lot of MemAvailable but falling cache and raising PSI To: Stefan Priebe - Profihost AG , Michal Hocko Cc: "linux-mm@kvack.org" , l.roehrs@profihost.ag, cgroups@vger.kernel.org, Johannes Weiner References: <4b4ba042-3741-7b16-2292-198c569da2aa@profihost.ag> <20190905114022.GH3838@dhcp22.suse.cz> <7a3d23f2-b5fe-b4c0-41cd-e79070637bd9@profihost.ag> <20190909082732.GC27159@dhcp22.suse.cz> <1d9ee19a-98c9-cd78-1e5b-21d9d6e36792@profihost.ag> <3ca34a49-6327-e6fd-2754-9b0700d87785@profihost.ag> From: Vlastimil Babka Message-ID: Date: Mon, 9 Sep 2019 14:21:10 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <3ca34a49-6327-e6fd-2754-9b0700d87785@profihost.ag> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US 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: On 9/9/19 2:09 PM, Stefan Priebe - Profihost AG wrote: >=20 > Am 09.09.19 um 13:49 schrieb Vlastimil Babka: >> On 9/9/19 10:54 AM, Stefan Priebe - Profihost AG wrote: >>>> Do you have more snapshots of /proc/vmstat as suggested by Vlastimil= and >>>> me earlier in this thread? Seeing the overall progress would tell us >>>> much more than before and after. Or have I missed this data? >>> >>> I needed to wait until today to grab again such a situation but from >>> what i know it is very clear that MemFree is low and than the kernel >>> starts to drop the chaches. >>> >>> Attached you'll find two log files. >> >> Thanks, what about my other requests/suggestions from earlier? >=20 > Sorry i missed your email. >=20 >> 1. How does /proc/pagetypeinfo look like? >=20 > # cat /proc/pagetypeinfo > Page block order: 9 > Pages per block: 512 Looks like it might be fragmented, but was that snapshot taken in the=20 situation where there's free memory and the system still drops cache? >> 2. Could you also try if the bad trend stops after you execute: >> =C2=A0echo never > /sys/kernel/mm/transparent_hugepage/defrag >> and report the result? >=20 > it's pretty difficult to catch those moments. Is it OK so set the value > now and monitor if it happens again? Well if it doesn't happen again after changing that setting, it would=20 definitely point at THP interactions. > Just to let you know: > I've now also some more servers where memfree show 10-20Gb but cache > drops suddently and memory PSI raises. You mean those are in that state right now? So how does=20 /proc/pagetypeinfo look there, and would changing the defrag setting help= ? > Greets, > Stefan >=20