From 9ede209e83693cf3f6b64f61ab4b65f2f809cb50 Mon Sep 17 00:00:00 2001 From: Jens Axboe <jens.axboe@oracle.com> Date: Fri, 19 Jan 2007 12:11:44 +1100 Subject: [PATCH] cfq-iosched: improve continue or break logic in cfq_dispatch This improves performance considerably for sync requests when you have command queuing enabled. Signed-off-by: Jens Axboe <jens.axboe@oracle.com> --- block/cfq-iosched.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 6aa5523f514cc..b6491c020f26e 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -1057,6 +1057,14 @@ cfq_dispatch_requests(request_queue_t *q, int force) if (prev_cfqq == cfqq) break; + /* + * So we have dispatched before in this round, if the + * next queue has idling enabled (must be sync), don't + * allow it service until the previous have continued. + */ + if (cfqd->rq_in_driver && cfq_cfqq_idle_window(cfqq)) + break; + cfq_clear_cfqq_must_dispatch(cfqq); cfq_clear_cfqq_wait_request(cfqq); del_timer(&cfqd->idle_slice_timer); @@ -1066,14 +1074,6 @@ cfq_dispatch_requests(request_queue_t *q, int force) max_dispatch = 1; dispatched += __cfq_dispatch_requests(cfqd, cfqq, max_dispatch); - - /* - * If the dispatch cfqq has idling enabled and is still - * the active queue, break out. - */ - if (cfq_cfqq_idle_window(cfqq) && cfqd->active_queue) - break; - prev_cfqq = cfqq; } -- 2.30.2