diff options
| -rw-r--r-- | block/cfq-iosched.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index cba8a5d91bf..56e9d8503cf 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -1903,10 +1903,17 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, * Remember that we saw a request from this process, but * don't start queuing just yet. Otherwise we risk seeing lots * of tiny requests, because we disrupt the normal plugging - * and merging. + * and merging. If the request is already larger than a single + * page, let it rip immediately. For that case we assume that + * merging is already done. */ - if (cfq_cfqq_wait_request(cfqq)) + if (cfq_cfqq_wait_request(cfqq)) { + if (blk_rq_bytes(rq) > PAGE_CACHE_SIZE) { + del_timer(&cfqd->idle_slice_timer); + blk_start_queueing(cfqd->queue); + } cfq_mark_cfqq_must_dispatch(cfqq); + } } else if (cfq_should_preempt(cfqd, cfqq, rq)) { /* * not the active queue - expire current slice if it is |