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authorJens Axboe <axboe@suse.de>2006-06-13 10:26:10 +0400
committerJens Axboe <axboe@nelson.home.kernel.dk>2006-06-23 19:10:39 +0400
commitb31dc66a54ad986b6b73bdc49c8efc17cbad1833 (patch)
tree5591383c1cbffe11512da889c971f899333f1a44 /block/ll_rw_blk.c
parent271f18f102c789f59644bb6c53a69da1df72b2f4 (diff)
downloadlinux-b31dc66a54ad986b6b73bdc49c8efc17cbad1833.tar.xz
[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 'block/ll_rw_blk.c')
-rw-r--r--block/ll_rw_blk.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 17c42ddd31db..2270bb451385 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -2827,6 +2827,9 @@ static void init_request_from_bio(struct request *req, struct bio *bio)
if (unlikely(bio_barrier(bio)))
req->flags |= (REQ_HARDBARRIER | REQ_NOMERGE);
+ if (bio_sync(bio))
+ req->flags |= REQ_RW_SYNC;
+
req->errors = 0;
req->hard_sector = req->sector = bio->bi_sector;
req->hard_nr_sectors = req->nr_sectors = bio_sectors(bio);