From: Jan Kara <jack@suse.cz>
To: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Jan Kara <jack@suse.cz>, "Darrick J. Wong" <djwong@us.ibm.com>,
Theodore Tso <tytso@mit.edu>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Jens Axboe <axboe@kernel.dk>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Jeff Layton <jlayton@redhat.com>,
Dave Chinner <david@fromorbit.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
Dave Hansen <dave@linux.vnet.ibm.com>,
Christoph Hellwig <hch@infradead.org>,
linux-mm@kvack.org, Chris Mason <chris.mason@oracle.com>,
Joel Becker <jlbec@evilplan.org>,
linux-scsi <linux-scsi@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
linux-ext4@vger.kernel.org, Mingming Cao <mcao@us.ibm.com>
Subject: Re: [PATCHSET v3.1 0/7] data integrity: Stabilize pages during writeback for various fses
Date: Tue, 10 May 2011 18:22:37 +0200 [thread overview]
Message-ID: <20110510162237.GM4402@quack.suse.cz> (raw)
In-Reply-To: <87zkmupmaq.fsf@devron.myhome.or.jp>
On Wed 11-05-11 01:12:13, OGAWA Hirofumi wrote:
> Jan Kara <jack@suse.cz> writes:
>
> >> Did you already consider, to copy only if page was writeback (like
> >> copy-on-write)? I.e. if page is on I/O, copy, then switch the page for
> >> writing new data.
> > Yes, that was considered as well. We'd have to essentially migrate the
> > page that is under writeback and should be written to. You are going to pay
> > the cost of page allocation, copy, increased memory & cache pressure.
> > Depending on your backing storage and workload this may or may not be better
> > than waiting for IO...
>
> Maybe possible, but you really think on usual case just blocking is
> better?
Define usual case... As Christoph noted, we don't currently have a real
practical case where blocking would matter (since frequent rewrites are
rather rare). So defining what is usual when we don't have a single real
case is kind of tough ;)
Honza
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR
next prev parent reply other threads:[~2011-05-10 16:22 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-09 23:03 [PATCHSET v3.1 0/7] data integrity: Stabilize pages during writeback for various fses Darrick J. Wong
2011-05-09 23:03 ` [PATCH 1/7] mm: Wait for writeback when grabbing pages to begin a write Darrick J. Wong
2011-05-09 23:03 ` [PATCH 2/7] fs: block_page_mkwrite should wait for writeback to finish Darrick J. Wong
2011-05-10 12:41 ` Jan Kara
2011-05-10 17:12 ` Darrick J. Wong
2011-05-09 23:03 ` [PATCH 3/7] mm: Provide stub page_mkwrite functionality to stabilize pages during writes Darrick J. Wong
2011-05-09 23:03 ` [PATCH 4/7] ext4: Clean up some wait_on_page_writeback calls Darrick J. Wong
2011-05-18 18:16 ` [4/7] " Ted Ts'o
2011-05-09 23:03 ` [PATCH 5/7] ext4: Wait for writeback to complete while making pages writable Darrick J. Wong
2011-05-18 18:17 ` [5/7] " Ted Ts'o
2011-05-09 23:04 ` [PATCH 6/7] ext2: Lock buffer_head during metadata update Darrick J. Wong
2011-05-09 23:04 ` [PATCH 7/7] fat: Lock buffer_head during metadata updates Darrick J. Wong
2011-05-10 0:06 ` [PATCHSET v3.1 0/7] data integrity: Stabilize pages during writeback for various fses Dave Chinner
2011-05-10 1:59 ` OGAWA Hirofumi
2011-05-10 12:38 ` Jan Kara
2011-05-10 13:12 ` OGAWA Hirofumi
2011-05-10 13:29 ` Jan Kara
2011-05-10 13:46 ` OGAWA Hirofumi
2011-05-10 14:05 ` OGAWA Hirofumi
2011-05-10 14:54 ` Jan Kara
2011-05-10 16:12 ` OGAWA Hirofumi
2011-05-10 16:22 ` Jan Kara [this message]
2011-05-10 16:28 ` OGAWA Hirofumi
2011-05-16 18:47 ` Darrick J. Wong
2011-05-16 19:31 ` OGAWA Hirofumi
2011-05-17 1:23 ` Darrick J. Wong
2011-05-17 3:30 ` OGAWA Hirofumi
2011-10-23 16:38 ` Andy Lutomirski
2011-05-10 13:36 ` Christoph Hellwig
2011-05-10 13:52 ` OGAWA Hirofumi
2011-05-10 14:49 ` Jan Kara
2011-05-10 15:24 ` OGAWA Hirofumi
2011-05-10 16:18 ` Jan Kara
2011-05-10 16:29 ` OGAWA Hirofumi
2011-05-10 17:03 ` Jan Kara
2011-05-10 17:03 ` Christoph Hellwig
2011-05-10 20:50 ` OGAWA Hirofumi
2011-05-11 5:55 ` Christoph Hellwig
2011-05-11 9:36 ` OGAWA Hirofumi
2011-05-10 12:51 ` Jan Kara
2011-05-10 16:24 ` Chris Mason
2011-05-11 18:19 ` Darrick J. Wong
2011-05-12 9:42 ` Jan Kara
2011-05-16 18:49 ` Darrick J. Wong
2011-05-16 18:59 ` Jan Kara
2011-05-16 19:09 ` Darrick J. Wong
2011-05-16 19:04 ` Darrick J. Wong
2011-05-16 20:27 ` Christoph Hellwig
2011-05-16 20:55 ` Darrick J. Wong
2011-05-17 14:01 ` Christoph Hellwig
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