linux/include
Darrick J. Wong ffecfd1a72 block: optionally snapshot page contents to provide stable pages during write
This provides a band-aid to provide stable page writes on jbd without
needing to backport the fixed locking and page writeback bit handling
schemes of jbd2.  The band-aid works by using bounce buffers to snapshot
page contents instead of waiting.

For those wondering about the ext3 bandage -- fixing the jbd locking
(which was done as part of ext4dev years ago) is a lot of surgery, and
setting PG_writeback on data pages when we actually hold the page lock
dropped ext3 performance by nearly an order of magnitude.  If we're
going to migrate iscsi and raid to use stable page writes, the
complaints about high latency will likely return.  We might as well
centralize their page snapshotting thing to one place.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-21 17:22:20 -08:00
..
acpi Merge branch 'acpi-cleanup' 2013-02-15 13:58:30 +01:00
asm-generic The common clock framework changes for 3.9 are almost entirely fixes. 2013-02-20 11:02:10 -08:00
clocksource
crypto crypto: cast5/cast6 - move lookup tables to shared module 2012-12-06 17:16:26 +08:00
drm Merge branch 'drm-intel-fixes' of git://people.freedesktop.org/~danvet/drm-intel 2013-01-11 07:52:48 +10:00
keys
linux mm: only enforce stable page writes if the backing device requires it 2013-02-21 17:22:19 -08:00
math-emu
media
memory
misc
net ipv6: fix race condition regarding dst->expires and dst->from. 2013-02-20 15:11:45 -05:00
pcmcia
ras
rdma UAPI: Remove empty Kbuild files 2013-01-02 17:36:10 -08:00
rxrpc
scsi SCSI misc on 20121212 2012-12-13 19:20:31 -08:00
sound Merge remote-tracking branch 'asoc/fix/cs4271' into tmp 2013-01-10 12:22:11 +00:00
target target: Introduce TCM_NO_SENSE 2013-01-10 20:06:08 -08:00
trace ACPI and power management updates for 3.9-rc1 2013-02-20 11:26:56 -08:00
uapi block: optionally snapshot page contents to provide stable pages during write 2013-02-21 17:22:20 -08:00
video video: s3c-fb: fix typo in definition of VIDCON1_VSTATUS_FRONTPORCH value 2013-02-21 17:22:18 -08:00
xen Bugfixes: 2012-12-18 12:26:54 -08:00
Kbuild UAPI: Remove empty Kbuild files 2013-01-02 17:36:10 -08:00