From b31dc66a54ad986b6b73bdc49c8efc17cbad1833 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 13 Jun 2006 08:26:10 +0200 Subject: [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 --- block/as-iosched.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'block/as-iosched.c') 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; -- cgit v1.2.3