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| author | Jens Axboe <jens.axboe@oracle.com> | 2007-01-19 12:11:44 +1100 |
|---|---|---|
| committer | Jens Axboe <axboe@carl.home.kernel.dk> | 2007-02-11 23:14:45 +0100 |
| commit | 9ede209e83693cf3f6b64f61ab4b65f2f809cb50 (patch) | |
| tree | a91ad6e7fd1b8589ecf4c8e5e027a397d89ccd6f /block | |
| parent | 28f95cbc3ec01f2c7d248e1a4a384f37e9c2ab16 (diff) | |
| download | lwn-9ede209e83693cf3f6b64f61ab4b65f2f809cb50.tar.gz lwn-9ede209e83693cf3f6b64f61ab4b65f2f809cb50.zip | |
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>
Diffstat (limited to 'block')
| -rw-r--r-- | block/cfq-iosched.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 6aa5523f514c..b6491c020f26 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; } |