From: Mike Galbraith Subject: Re: v4.9, 4.4-final: 28 bioset threads on small notebook, 36 threads on cellphone Date: Wed, 08 Feb 2017 07:57:04 +0100 Message-ID: <1486537024.4387.4.camel@gmx.de> References: <20151211104937.GA23165@amd> <20151211140841.GA22873@redhat.com> <20160220174035.GA16459@amd> <20160220184258.GA3753@amd> <20160220195136.GA27149@redhat.com> <20160220200432.GB22120@amd> <20170206125309.GA29395@amd> <20170207014724.74tb37jj7u66lww3@moria.home.lan> <20170207024906.4oswyuvxfnqkvbhr@moria.home.lan> <20170207203911.GA16980@amd> <20170207204510.qr2l2rg42ez2hobh@moria.home.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170207204510.qr2l2rg42ez2hobh@moria.home.lan> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Kent Overstreet , Pavel Machek Cc: oleg.drokin@intel.com, ming.l@ssi.samsung.com, andreas.dilger@intel.com, Mike Snitzer , martin.petersen@oracle.com, minchan@kernel.org, jkosina@suse.cz, ming.lei@canonical.com, kernel list , jim@jtan.com, pjk1939@linux.vnet.ibm.com, axboe@fb.com, geoff@infradead.org, dm-devel@redhat.com, dpark@posteo.net, ngupta@vflare.org, hch@lst.de, agk@redhat.com List-Id: dm-devel.ids On Tue, 2017-02-07 at 19:58 -0900, Kent Overstreet wrote: > On Tue, Feb 07, 2017 at 09:39:11PM +0100, Pavel Machek wrote: > > On Mon 2017-02-06 17:49:06, Kent Overstreet wrote: > > > On Mon, Feb 06, 2017 at 04:47:24PM -0900, Kent Overstreet wrote: > > > > On Mon, Feb 06, 2017 at 01:53:09PM +0100, Pavel Machek wrote: > > > > > Still there on v4.9, 36 threads on nokia n900 cellphone. > > > > > > > > > > So.. what needs to be done there? > > > > > > > But, I just got an idea for how to handle this that might be halfway sane, maybe > > > > I'll try and come up with a patch... > > > > > > Ok, here's such a patch, only lightly tested: > > > > I guess it would be nice for me to test it... but what it is against? > > I tried after v4.10-rc5 and linux-next, but got rejects in both cases. > > Sorry, I forgot I had a few other patches in my branch that touch > mempool/biosets code. > > Also, after thinking about it more and looking at the relevant code, I'm pretty > sure we don't need rescuer threads for block devices that just split bios - i.e. > most of them, so I changed my patch to do that. > > Tested it by ripping out the current->bio_list checks/workarounds from the > bcache code, appears to work: Patch killed every last one of them, but.. homer:/root # dmesg|grep WARNING [ 11.701447] WARNING: CPU: 4 PID: 801 at block/bio.c:388 bio_alloc_bioset+0x1a7/0x240 [ 11.711027] WARNING: CPU: 4 PID: 801 at block/blk-core.c:2013 generic_make_request+0x191/0x1f0 [ 19.728989] WARNING: CPU: 0 PID: 717 at block/bio.c:388 bio_alloc_bioset+0x1a7/0x240 [ 19.737020] WARNING: CPU: 0 PID: 717 at block/blk-core.c:2013 generic_make_request+0x191/0x1f0 [ 19.746173] WARNING: CPU: 0 PID: 717 at block/bio.c:388 bio_alloc_bioset+0x1a7/0x240 [ 19.755260] WARNING: CPU: 0 PID: 717 at block/blk-core.c:2013 generic_make_request+0x191/0x1f0 [ 19.763837] WARNING: CPU: 0 PID: 717 at block/bio.c:388 bio_alloc_bioset+0x1a7/0x240 [ 19.772526] WARNING: CPU: 0 PID: 717 at block/blk-core.c:2013 generic_make_request+0x191/0x1f0