From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:42434 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932597AbeFFIqB (ORCPT ); Wed, 6 Jun 2018 04:46:01 -0400 Date: Wed, 6 Jun 2018 10:45:59 +0200 From: Michal Hocko To: Andrew Morton Cc: Chris Mason , Tetsuo Handa , bugzilla-daemon@bugzilla.kernel.org, bugzilla.kernel.org@plan9.de, linux-btrfs@vger.kernel.org, linux-mm@kvack.org, Jan Kara Subject: Re: [Bug 199931] New: systemd/rtorrent file data corruption when using echo 3 >/proc/sys/vm/drop_caches Message-ID: <20180606084559.GD32433@dhcp22.suse.cz> References: <20180605130329.f7069e01c5faacc08a10996c@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20180605130329.f7069e01c5faacc08a10996c@linux-foundation.org> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Tue 05-06-18 13:03:29, Andrew Morton wrote: [...] > > As for why we would do something silly as dropping the caches every hour (in a > > cronjob), we started doing this recently because after kernel 4.4, we got > > frequent OOM kills despite having gigabytes of available memory (e.g. 12GB in > > use, 20GB page cache and 16GB empty swap and bang, mysql gets killed). We found > > that that the debian 4.9 kernel is unusable, and 4.14 works, *iff* we use the > > above as an hourly cron job, so we did that, and afterwards run into > > rtorrent/journald corruption issues. Without the echo in place, mysql usually > > gets oom-killed after a few days of uptime. Do you have any oom reports to share? -- Michal Hocko SUSE Labs