From: Arjan van de Ven <arjan@infradead.org>
To: Theodore Tso <tytso@mit.edu>
Cc: Jens Axboe <jens.axboe@oracle.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Linux Kernel Developers List <linux-kernel@vger.kernel.org>,
Ext4 Developers List <linux-ext4@vger.kernel.org>
Subject: Re: [GIT PULL] Ext3 latency fixes
Date: Sat, 4 Apr 2009 16:33:49 -0700 [thread overview]
Message-ID: <20090404163349.20df1208@infradead.org> (raw)
In-Reply-To: <20090404232222.GA7480@mit.edu>
On Sat, 4 Apr 2009 19:22:22 -0400
Theodore Tso <tytso@mit.edu> wrote:
>
> However, the full latency fixes all the writes are synchronous, so it
> must be the case that the delays are caused by the fact that queue is
> getting implicitly unplugged after the synchronous write, and the
> problem is no longer the mixing of WRITE and WRITE_SYNC requests as
> posted in the commit log for 78f707bf. If we remove the automatic
> unplug for WRITE_SYNC requests, and add an explicit unplug where it is
> needed, that should fix the performance regression for this particular
> sqlite test case.
removing the unplug is bound to be bad; after all we're waiting on the
IO. But maybe it should be "make the unplug a REALLY short time".
At least for rotating storage. For non-rotating .. I'd never wait.
--
Arjan van de Ven Intel Open Source Technology Centre
For development, discussion and tips for power savings,
visit http://www.lesswatts.org
next prev parent reply other threads:[~2009-04-04 23:32 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-03 7:01 [GIT PULL] Ext3 latency fixes Theodore Ts'o
2009-04-03 7:01 ` [PATCH 1/4] block_write_full_page: Use synchronous writes for WBC_SYNC_ALL writebacks Theodore Ts'o
2009-04-03 7:01 ` [PATCH 2/4] ext3: Use WRITE_SYNC for commits which are caused by fsync() Theodore Ts'o
2009-04-03 7:01 ` [PATCH 3/4] ext3: Add replace-on-truncate hueristics for data=writeback mode Theodore Ts'o
2009-04-03 7:01 ` [PATCH 4/4] ext3: Add replace-on-rename " Theodore Ts'o
2009-04-03 18:24 ` [GIT PULL] Ext3 latency fixes Linus Torvalds
2009-04-03 18:47 ` Jens Axboe
2009-04-03 19:13 ` Theodore Tso
2009-04-03 21:01 ` Chris Mason
2009-04-03 19:02 ` Linus Torvalds
2009-04-03 20:41 ` Linus Torvalds
2009-04-04 13:57 ` Theodore Tso
2009-04-04 15:16 ` Jens Axboe
2009-04-04 15:57 ` Linus Torvalds
2009-04-04 16:06 ` Linus Torvalds
2009-04-04 17:36 ` Jens Axboe
2009-04-04 17:34 ` Jens Axboe
2009-04-04 17:44 ` Linus Torvalds
2009-04-04 18:00 ` Trenton D. Adams
2009-04-04 18:01 ` Jens Axboe
2009-04-04 18:10 ` Linus Torvalds
2009-04-04 23:22 ` Theodore Tso
2009-04-04 23:33 ` Arjan van de Ven [this message]
2009-04-05 0:10 ` Theodore Tso
2009-04-05 15:05 ` Arjan van de Ven
2009-04-05 17:01 ` Linus Torvalds
2009-04-05 17:15 ` Mark Lord
2009-04-05 20:57 ` Jeff Garzik
2009-04-05 23:48 ` Arjan van de Ven
2009-04-06 2:32 ` Mark Lord
2009-04-06 5:47 ` Jeff Garzik
2009-04-07 18:18 ` Linus Torvalds
2009-04-07 18:22 ` Linus Torvalds
2009-04-07 19:40 ` [PATCH libata: add SSD detection hueristic; move SSD setup to ata_dev_configure (was Re: [GIT PULL] Ext3 latency fixes) Jeff Garzik
2009-04-09 18:21 ` Tejun Heo
2009-04-18 3:02 ` George Spelvin
2009-04-06 8:13 ` [GIT PULL] Ext3 latency fixes Jens Axboe
2009-04-05 18:56 ` Arjan van de Ven
2009-04-05 19:34 ` Linus Torvalds
2009-04-05 20:06 ` Arjan van de Ven
2009-04-06 6:25 ` Jens Axboe
2009-04-06 6:05 ` Theodore Tso
2009-04-06 6:23 ` Jens Axboe
2009-04-06 8:16 ` Jens Axboe
2009-04-06 14:48 ` Linus Torvalds
2009-04-06 15:09 ` Jens Axboe
2009-04-06 6:15 ` Jens Axboe
2009-04-04 20:18 ` Ingo Molnar
2009-04-06 21:50 ` Lennart Sorensen
2009-04-07 13:31 ` Mark Lord
2009-04-07 14:48 ` Lennart Sorensen
2009-04-07 19:21 ` Mark Lord
2009-04-07 19:57 ` Lennart Sorensen
2009-04-04 20:56 ` Arjan van de Ven
2009-04-06 7:06 ` Jens Axboe
2009-04-07 15:39 ` Indan Zupancic
2009-04-04 19:18 ` Theodore Tso
2009-04-06 8:12 ` Jens Axboe
2009-04-04 22:13 ` Linus Torvalds
2009-04-04 22:19 ` Linus Torvalds
2009-04-05 0:20 ` Theodore Tso
2009-04-03 19:54 ` Theodore Tso
2009-04-08 23:40 Theodore Ts'o
2009-04-09 15:49 ` Linus Torvalds
2009-04-09 16:23 ` Chris Mason
2009-04-09 17:49 ` Jan Kara
2009-04-09 18:10 ` Chris Mason
2009-04-09 19:04 ` Jan Kara
2009-04-09 17:36 ` Jan Kara
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