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=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 18917C3A5AB for ; Thu, 5 Sep 2019 11:40:26 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E96B221848 for ; Thu, 5 Sep 2019 11:40:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E96B221848 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7F84F6B0290; Thu, 5 Sep 2019 07:40:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7A7D36B0292; Thu, 5 Sep 2019 07:40:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6BCCA6B0293; Thu, 5 Sep 2019 07:40:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0232.hostedemail.com [216.40.44.232]) by kanga.kvack.org (Postfix) with ESMTP id 45D2C6B0290 for ; Thu, 5 Sep 2019 07:40:25 -0400 (EDT) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id E19DA82437C9 for ; Thu, 5 Sep 2019 11:40:24 +0000 (UTC) X-FDA: 75900673968.13.gold48_5ae390929cf55 X-HE-Tag: gold48_5ae390929cf55 X-Filterd-Recvd-Size: 1744 Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) by imf08.hostedemail.com (Postfix) with ESMTP for ; Thu, 5 Sep 2019 11:40:24 +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 329E9AF05; Thu, 5 Sep 2019 11:40:23 +0000 (UTC) Date: Thu, 5 Sep 2019 13:40:22 +0200 From: Michal Hocko To: Stefan Priebe - Profihost AG Cc: "linux-mm@kvack.org" , l.roehrs@profihost.ag, cgroups@vger.kernel.org, Johannes Weiner Subject: Re: lot of MemAvailable but falling cache and raising PSI Message-ID: <20190905114022.GH3838@dhcp22.suse.cz> References: <4b4ba042-3741-7b16-2292-198c569da2aa@profihost.ag> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4b4ba042-3741-7b16-2292-198c569da2aa@profihost.ag> User-Agent: Mutt/1.10.1 (2018-07-13) 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 Thu 05-09-19 13:27:10, Stefan Priebe - Profihost AG wrote: > Hello all, > > i hope you can help me again to understand the current MemAvailable > value in the linux kernel. I'm running a 4.19.52 kernel + psi patches in > this case. > > I'm seeing the following behaviour i don't understand and ask for help. > > While MemAvailable shows 5G the kernel starts to drop cache from 4G down > to 1G while the apache spawns some PHP processes. After that the PSI > mem.some value rises and the kernel tries to reclaim memory but > MemAvailable stays at 5G. > > Any ideas? Can you collect /proc/vmstat (every second or so) and post it while this is the case please? -- Michal Hocko SUSE Labs