[PATCH] Kill PF_SYNCWRITE flag
commitb31dc66a54ad986b6b73bdc49c8efc17cbad1833
authorJens Axboe <axboe@suse.de>
Tue, 13 Jun 2006 06:26:10 +0000 (13 08:26 +0200)
committerJens Axboe <axboe@nelson.home.kernel.dk>
Fri, 23 Jun 2006 15:10:39 +0000 (23 17:10 +0200)
tree5591383c1cbffe11512da889c971f899333f1a44
parent271f18f102c789f59644bb6c53a69da1df72b2f4
[PATCH] Kill PF_SYNCWRITE flag

A process flag to indicate whether we are doing sync io is incredibly
ugly. It also causes performance problems when one does a lot of async
io and then proceeds to sync it. Part of the io will go out as async,
and the other part as sync. This causes a disconnect between the
previously submitted io and the synced io. For io schedulers such as CFQ,
this will cause us lost merges and suboptimal behaviour in scheduling.

Remove PF_SYNCWRITE completely from the fsync/msync paths, and let
the O_DIRECT path just directly indicate that the writes are sync
by using WRITE_SYNC instead.

Signed-off-by: Jens Axboe <axboe@suse.de>
block/as-iosched.c
block/cfq-iosched.c
block/ll_rw_blk.c
drivers/usb/gadget/file_storage.c
fs/buffer.c
fs/direct-io.c
fs/fs-writeback.c
include/linux/blkdev.h
include/linux/sched.h
mm/msync.c