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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 /block/as-iosched.c
parent271f18f102c789f59644bb6c53a69da1df72b2f4 (diff)
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[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/as-iosched.c')
-rw-r--r--block/as-iosched.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/block/as-iosched.c b/block/as-iosched.c
index 9b13d72ffef..56c99fa037d 100644
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -1339,7 +1339,7 @@ static void as_add_request(request_queue_t *q, struct request *rq)
arq->state = AS_RQ_NEW;
if (rq_data_dir(arq->request) == READ
- || current->flags&PF_SYNCWRITE)
+ || (arq->request->flags & REQ_RW_SYNC))
arq->is_sync = 1;
else
arq->is_sync = 0;