diff options
Diffstat (limited to 'block/cfq-iosched.c')
| -rw-r--r-- | block/cfq-iosched.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 141104835952..6dbee46240c5 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -141,6 +141,8 @@ struct cfq_queue { int queued[2]; /* currently allocated requests */ int allocated[2]; + /* pending metadata requests */ + int meta_pending; /* fifo list of requests in sort_list */ struct list_head fifo; @@ -248,6 +250,10 @@ cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2) return rq1; else if (rq_is_sync(rq2) && !rq_is_sync(rq1)) return rq2; + if (rq_is_meta(rq1) && !rq_is_meta(rq2)) + return rq1; + else if (rq_is_meta(rq2) && !rq_is_meta(rq1)) + return rq2; s1 = rq1->sector; s2 = rq2->sector; @@ -510,6 +516,11 @@ static void cfq_remove_request(struct request *rq) list_del_init(&rq->queuelist); cfq_del_rq_rb(rq); + + if (rq_is_meta(rq)) { + WARN_ON(!cfqq->meta_pending); + cfqq->meta_pending--; + } } static int @@ -1527,8 +1538,18 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, */ if (new_cfqq->slice_left < cfqd->cfq_slice_idle) return 0; + /* + * if the new request is sync, but the currently running queue is + * not, let the sync request have priority. + */ if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq)) return 1; + /* + * So both queues are sync. Let the new request get disk time if + * it's a metadata request and the current queue is doing regular IO. + */ + if (rq_is_meta(rq) && !cfqq->meta_pending) + return 1; return 0; } @@ -1564,6 +1585,9 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, { struct cfq_io_context *cic = RQ_CIC(rq); + if (rq_is_meta(rq)) + cfqq->meta_pending++; + /* * check if this request is a better next-serve candidate)) { */ |