From 7749a8d423c483a51983b666613acda1a4dd9c1b Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 13 Dec 2006 13:02:26 +0100 Subject: [PATCH] Propagate down request sync flag We need to do this, otherwise the io schedulers don't get access to the sync flag. Then they cannot tell the difference between a regular write and an O_DIRECT write, which can cause a performance loss. Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'block/cfq-iosched.c') diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 78c6b312bd3..533a2938ffd 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -219,9 +219,12 @@ static int cfq_queue_empty(request_queue_t *q) return !cfqd->busy_queues; } -static inline pid_t cfq_queue_pid(struct task_struct *task, int rw) +static inline pid_t cfq_queue_pid(struct task_struct *task, int rw, int is_sync) { - if (rw == READ || rw == WRITE_SYNC) + /* + * Use the per-process queue, for read requests and syncronous writes + */ + if (!(rw & REQ_RW) || is_sync) return task->pid; return CFQ_KEY_ASYNC; @@ -473,7 +476,7 @@ static struct request * cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio) { struct task_struct *tsk = current; - pid_t key = cfq_queue_pid(tsk, bio_data_dir(bio)); + pid_t key = cfq_queue_pid(tsk, bio_data_dir(bio), bio_sync(bio)); struct cfq_queue *cfqq; cfqq = cfq_find_cfq_hash(cfqd, key, tsk->ioprio); @@ -1748,6 +1751,9 @@ static int cfq_may_queue(request_queue_t *q, int rw) struct cfq_data *cfqd = q->elevator->elevator_data; struct task_struct *tsk = current; struct cfq_queue *cfqq; + unsigned int key; + + key = cfq_queue_pid(tsk, rw, rw & REQ_RW_SYNC); /* * don't force setup of a queue from here, as a call to may_queue @@ -1755,7 +1761,7 @@ static int cfq_may_queue(request_queue_t *q, int rw) * so just lookup a possibly existing queue, or return 'may queue' * if that fails */ - cfqq = cfq_find_cfq_hash(cfqd, cfq_queue_pid(tsk, rw), tsk->ioprio); + cfqq = cfq_find_cfq_hash(cfqd, key, tsk->ioprio); if (cfqq) { cfq_init_prio_data(cfqq); cfq_prio_boost(cfqq); @@ -1798,10 +1804,10 @@ cfq_set_request(request_queue_t *q, struct request *rq, gfp_t gfp_mask) struct task_struct *tsk = current; struct cfq_io_context *cic; const int rw = rq_data_dir(rq); - pid_t key = cfq_queue_pid(tsk, rw); + const int is_sync = rq_is_sync(rq); + pid_t key = cfq_queue_pid(tsk, rw, is_sync); struct cfq_queue *cfqq; unsigned long flags; - int is_sync = key != CFQ_KEY_ASYNC; might_sleep_if(gfp_mask & __GFP_WAIT); -- cgit v1.2.3