From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f69.google.com (mail-wm0-f69.google.com [74.125.82.69]) by kanga.kvack.org (Postfix) with ESMTP id F34B96B0005 for ; Wed, 6 Jun 2018 04:46:02 -0400 (EDT) Received: by mail-wm0-f69.google.com with SMTP id g73-v6so2740840wmc.5 for ; Wed, 06 Jun 2018 01:46:02 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id i56-v6si608054ede.173.2018.06.06.01.46.01 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 06 Jun 2018 01:46:01 -0700 (PDT) Date: Wed, 6 Jun 2018 10:45:59 +0200 From: Michal Hocko 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 Content-Disposition: inline In-Reply-To: <20180605130329.f7069e01c5faacc08a10996c@linux-foundation.org> Sender: owner-linux-mm@kvack.org List-ID: 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 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