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authorJens Axboe <axboe@suse.de>2006-06-13 08:26:10 +0200
committerJens Axboe <axboe@nelson.home.kernel.dk>2006-06-23 17:10:39 +0200
commitb31dc66a54ad986b6b73bdc49c8efc17cbad1833 (patch)
tree5591383c1cbffe11512da889c971f899333f1a44 /include/linux/blkdev.h
parent271f18f102c789f59644bb6c53a69da1df72b2f4 (diff)
downloadop-kernel-dev-b31dc66a54ad986b6b73bdc49c8efc17cbad1833.zip
op-kernel-dev-b31dc66a54ad986b6b73bdc49c8efc17cbad1833.tar.gz
[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>
Diffstat (limited to 'include/linux/blkdev.h')
-rw-r--r--include/linux/blkdev.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 3457e7b..482a21d 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -241,6 +241,7 @@ enum rq_flag_bits {
__REQ_PM_RESUME, /* resume request */
__REQ_PM_SHUTDOWN, /* shutdown request */
__REQ_ORDERED_COLOR, /* is before or after barrier */
+ __REQ_RW_SYNC, /* request is sync (O_DIRECT) */
__REQ_NR_BITS, /* stops here */
};
@@ -270,6 +271,7 @@ enum rq_flag_bits {
#define REQ_PM_RESUME (1 << __REQ_PM_RESUME)
#define REQ_PM_SHUTDOWN (1 << __REQ_PM_SHUTDOWN)
#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
+#define REQ_RW_SYNC (1 << __REQ_RW_SYNC)
/*
* State information carried for REQ_PM_SUSPEND and REQ_PM_RESUME
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