From: Tejun Heo <tj@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <jaxboe@fusionio.com>,
Ric Wheeler <rwheeler@redhat.com>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
"linux-ide@vger.kernel.org" <linux-ide@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-raid@vger.kernel.org" <linux-raid@vger.kernel.org>,
"James.Bottomley@suse.de" <James.Bottomley@suse.de>,
"tytso@mit.edu" <tytso@mit.edu>,
"chris.mason@oracle.com" <chris.mason@oracle.com>,
"swhiteho@redhat.com" <swhiteho@redhat.com>,
"konishi.ryusuke@lab.ntt.co.jp" <konishi.ryusuke@lab.ntt.co.jp>,
"dm-devel@redhat.com" <dm-devel@redhat.com>,
"vst@vlnb.net" <vst@vlnb.net>, "jack@suse.cz" <jack@suse.cz>,
"hare@suse.de" <hare@suse.de>
Subject: Re: [PATCHSET block#for-2.6.36-post] block: replace barrier with sequenced flush
Date: Mon, 23 Aug 2010 16:13:36 +0200 [thread overview]
Message-ID: <4C728210.6040605@kernel.org> (raw)
In-Reply-To: <20100823140823.GA23490@lst.de>
Hello,
On 08/23/2010 04:08 PM, Christoph Hellwig wrote:
> On Mon, Aug 23, 2010 at 04:01:15PM +0200, Jens Axboe wrote:
>> The problem purely exists on arrays that report write back cache enabled
>> AND don't implement SYNC_CACHE as a noop. Do any of them exist, or are
>> they purely urban legend?
>
> I haven't seen it. I don't care particularly about this case, but once
> it a while people want to disable flushing for testing or because they
> really don't care.
>
> What about adding a sysfs attribue to every request_queue that allows
> disabling the cache flushing feature? Compared to the barrier option
> this controls the feature at the right level and makes it available
> to everyone instead of beeing duplicated. After a while we can then
> simply ignore the barrier/nobarrier options.
Yeah, that sounds reasonable. blk_queue_flush() can be called anytime
without locking anyway, so it should be really easy to implement too.
Thanks.
--
tejun
next prev parent reply other threads:[~2010-08-23 14:13 UTC|newest]
Thread overview: 109+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-12 12:41 [PATCHSET block#for-2.6.36-post] block: replace barrier with sequenced flush Tejun Heo
2010-08-12 12:41 ` [PATCH 01/11] block/loop: queue ordered mode should be DRAIN_FLUSH Tejun Heo
2010-08-12 12:41 ` [PATCH 02/11] block: kill QUEUE_ORDERED_BY_TAG Tejun Heo
2010-08-13 12:56 ` Vladislav Bolkhovitin
2010-08-13 13:06 ` Christoph Hellwig
2010-08-12 12:41 ` [PATCH 03/11] block: deprecate barrier and replace blk_queue_ordered() with blk_queue_flush() Tejun Heo
2010-08-14 1:07 ` Jeremy Fitzhardinge
2010-08-14 9:42 ` hch
2010-08-16 20:38 ` Jeremy Fitzhardinge
2010-08-12 12:41 ` [PATCH 04/11] block: remove spurious uses of REQ_HARDBARRIER Tejun Heo
2010-08-12 12:41 ` [PATCH 05/11] block: misc cleanups in barrier code Tejun Heo
2010-08-12 12:41 ` [PATCH 06/11] block: drop barrier ordering by queue draining Tejun Heo
2010-08-12 12:41 ` [PATCH 07/11] block: rename blk-barrier.c to blk-flush.c Tejun Heo
2010-08-12 12:41 ` [PATCH 08/11] block: rename barrier/ordered to flush Tejun Heo
2010-08-17 13:26 ` Christoph Hellwig
2010-08-17 16:23 ` Tejun Heo
2010-08-17 17:08 ` Christoph Hellwig
2010-08-18 6:23 ` Tejun Heo
2010-08-12 12:41 ` [PATCH 09/11] block: implement REQ_FLUSH/FUA based interface for FLUSH/FUA requests Tejun Heo
2010-08-12 12:41 ` [PATCH 10/11] fs, block: propagate REQ_FLUSH/FUA interface to upper layers Tejun Heo
2010-08-12 21:24 ` Jan Kara
2010-08-13 7:19 ` Tejun Heo
2010-08-13 7:47 ` Christoph Hellwig
2010-08-16 16:33 ` [PATCH UPDATED " Tejun Heo
2010-08-12 12:41 ` [PATCH 11/11] block: use REQ_FLUSH in blkdev_issue_flush() Tejun Heo
2010-08-13 11:48 ` [PATCHSET block#for-2.6.36-post] block: replace barrier with sequenced flush Christoph Hellwig
2010-08-13 13:48 ` Tejun Heo
2010-08-13 14:38 ` Christoph Hellwig
2010-08-13 14:51 ` Tejun Heo
2010-08-14 10:36 ` Christoph Hellwig
2010-08-17 9:59 ` Tejun Heo
2010-08-17 13:19 ` Christoph Hellwig
2010-08-17 16:41 ` Tejun Heo
2010-08-17 16:59 ` Christoph Hellwig
2010-08-18 6:35 ` Tejun Heo
2010-08-18 8:11 ` Tejun Heo
2010-08-20 8:26 ` Kiyoshi Ueda
2010-08-23 12:14 ` Tejun Heo
2010-08-23 14:17 ` Mike Snitzer
2010-08-24 10:24 ` Kiyoshi Ueda
2010-08-24 16:59 ` Tejun Heo
2010-08-24 17:52 ` Mike Snitzer
2010-08-24 18:14 ` Tejun Heo
2010-08-25 8:00 ` Kiyoshi Ueda
2010-08-25 15:28 ` Mike Snitzer
2010-08-27 9:47 ` Kiyoshi Ueda
2010-08-27 13:49 ` Mike Snitzer
2010-08-30 6:13 ` Kiyoshi Ueda
2010-09-01 0:55 ` safety of retrying SYNCHRONIZE CACHE [was: Re: [PATCHSET block#for-2.6.36-post] block: replace barrier with sequenced flush] Mike Snitzer
2010-09-01 7:32 ` Hannes Reinecke
2010-09-01 7:38 ` Hannes Reinecke
2010-08-25 15:59 ` [RFC] training mpath to discern between SCSI errors (was: Re: [PATCHSET block#for-2.6.36-post] block: replace barrier with sequenced flush) Mike Snitzer
2010-08-25 19:15 ` [RFC] training mpath to discern between SCSI errors Mike Christie
2010-08-30 11:38 ` Hannes Reinecke
2010-08-30 12:07 ` Sergei Shtylyov
2010-08-30 12:39 ` Hannes Reinecke
2010-08-30 14:52 ` [dm-devel] " Hannes Reinecke
2010-10-18 8:09 ` Jun'ichi Nomura
2010-10-18 11:55 ` Hannes Reinecke
2010-10-19 4:03 ` Jun'ichi Nomura
2010-11-19 3:11 ` [dm-devel] " Malahal Naineni
2010-11-30 22:59 ` Mike Snitzer
2010-12-07 23:16 ` [RFC PATCH 0/3] differentiate between I/O errors Mike Snitzer
2010-12-07 23:16 ` [RFC PATCH v2 1/3] scsi: Detailed " Mike Snitzer
2010-12-07 23:16 ` [RFC PATCH v2 2/3] dm mpath: propagate target errors immediately Mike Snitzer
2010-12-07 23:16 ` [RFC PATCH 3/3] block: improve detail in I/O error messages Mike Snitzer
2010-12-08 11:28 ` Sergei Shtylyov
2010-12-08 15:05 ` [PATCH v2 " Mike Snitzer
2010-12-10 23:40 ` [RFC PATCH 0/3] differentiate between I/O errors Malahal Naineni
2011-01-14 1:15 ` Mike Snitzer
2010-12-17 9:47 ` training mpath to discern between SCSI errors Hannes Reinecke
2010-12-17 14:06 ` Mike Snitzer
2011-01-14 1:09 ` Mike Snitzer
2011-01-14 7:45 ` Hannes Reinecke
2011-01-14 13:59 ` Mike Snitzer
2010-08-24 17:11 ` [PATCHSET block#for-2.6.36-post] block: replace barrier with sequenced flush Vladislav Bolkhovitin
2010-08-24 23:14 ` Alan Cox
2010-08-13 12:55 ` Vladislav Bolkhovitin
2010-08-13 13:17 ` Christoph Hellwig
2010-08-18 19:29 ` Vladislav Bolkhovitin
2010-08-13 13:21 ` Tejun Heo
2010-08-18 19:30 ` Vladislav Bolkhovitin
2010-08-19 9:51 ` Tejun Heo
2010-08-30 9:54 ` Hannes Reinecke
2010-08-30 20:34 ` Vladislav Bolkhovitin
2010-08-18 9:46 ` Christoph Hellwig
2010-08-19 9:57 ` Tejun Heo
2010-08-19 10:20 ` Christoph Hellwig
2010-08-19 10:22 ` Tejun Heo
2010-08-20 13:22 ` Christoph Hellwig
2010-08-20 15:18 ` Ric Wheeler
2010-08-20 16:00 ` Chris Mason
2010-08-20 16:02 ` Ric Wheeler
2010-08-23 12:30 ` Tejun Heo
2010-08-23 12:48 ` Christoph Hellwig
2010-08-23 13:58 ` Ric Wheeler
2010-08-23 14:01 ` Jens Axboe
2010-08-23 14:08 ` Christoph Hellwig
2010-08-23 14:13 ` Tejun Heo [this message]
2010-08-23 14:19 ` Christoph Hellwig
2010-08-25 11:31 ` Jens Axboe
2010-08-30 10:04 ` Hannes Reinecke
2010-08-23 15:19 ` Ric Wheeler
2010-08-23 16:45 ` Sergey Vlasov
2010-08-23 16:49 ` [dm-devel] " Ric Wheeler
2010-08-23 12:36 ` Tejun Heo
2010-08-23 14:05 ` Christoph Hellwig
2010-08-23 14:15 ` [PATCH] block: simplify queue_next_fseq Christoph Hellwig
2010-08-23 16:28 ` OT grammar nit " John Robinson
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