From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc MERLIN Subject: Re: echo dev > /sys/fs/bcache/register gives page allocation failure: order:4, mode:0x2040d0 Date: Mon, 15 Feb 2016 07:32:36 -0800 Message-ID: <20160215153236.GI4115@merlins.org> References: <20160215060410.GA30802@merlins.org> <20160215121104.GA30514@kmo-pixel> <20160215060410.GA30802@merlins.org> <20160215120255.GE18134@c203.arch.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from magic.merlins.org ([209.81.13.136]:49154 "EHLO mail1.merlins.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751821AbcBOPc5 (ORCPT ); Mon, 15 Feb 2016 10:32:57 -0500 Content-Disposition: inline In-Reply-To: <20160215121104.GA30514@kmo-pixel> <20160215120255.GE18134@c203.arch.suse.de> Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: Johannes Thumshirn , Kent Overstreet Cc: linux-bcache@vger.kernel.org On Mon, Feb 15, 2016 at 01:02:55PM +0100, Johannes Thumshirn wrote: > > So I did > > make-bcache -B /dev/md5 > > echo /dev/md5 > /sys/fs/bcache/register > > > > and it fails: > > bash: page allocation failure: order:4, mode:0x2040d0 > > Is this system under some kind of memory preassure? Did this happen right > after boot or when the system was already running for quite some time? Uptime 17 days, it's a server that does a lot of I/O, but free shows I have 6GB available for buffer cache out of 8, so that shouldn't be too bad. Seems like I'm hitting an issue with memory fragmentation or a specific kind of memory not being available? (but I don't have any other kernel processes complaining about memory allocation failure, at least not consistently like here) On Mon, Feb 15, 2016 at 03:11:04AM -0900, Kent Overstreet wrote: > > and it fails: > > bash: page allocation failure: order:4, mode:0x2040d0 > > You want CONFIG_COMPACTION=y Good suggestion, but I already have it: gargamel:~# grep CONFIG_COMPACTION /boot/config-4.3.3-amd64-i915-volpreempt-20150421 CONFIG_COMPACTION=y Thanks for the replies, Marc -- "A mouse is a device used to point at the xterm you want to type in" - A.S.R. Microsoft is to operating systems .... .... what McDonalds is to gourmet cooking Home page: http://marc.merlins.org/