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author | Justin TerAvest <teravest@google.com> | 2011-03-12 16:54:00 +0100 |
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committer | Jens Axboe <jaxboe@fusionio.com> | 2011-03-12 16:54:00 +0100 |
commit | 167400d34070ebbc408dc0f447c4ddb4bf837360 (patch) | |
tree | 19100b0511a7e3e18f6f61d90a5fe5f1c40f59c4 /block/cfq-iosched.c | |
parent | 1f940bdfc0d03265d178d9dfd840d854819f797d (diff) | |
download | lwn-167400d34070ebbc408dc0f447c4ddb4bf837360.tar.gz lwn-167400d34070ebbc408dc0f447c4ddb4bf837360.zip |
blk-cgroup: Add unaccounted time to timeslice_used.
There are two kind of times that tasks are not charged for: the first
seek and the extra time slice used over the allocated timeslice. Both
of these exported as a new unaccounted_time stat.
I think it would be good to have this reported in 'time' as well, but
that is probably a separate discussion.
Signed-off-by: Justin TerAvest <teravest@google.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'block/cfq-iosched.c')
-rw-r--r-- | block/cfq-iosched.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index c826ef81c679..89e0d1cc14ba 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -899,7 +899,8 @@ cfq_group_service_tree_del(struct cfq_data *cfqd, struct cfq_group *cfqg) cfq_blkiocg_update_dequeue_stats(&cfqg->blkg, 1); } -static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq) +static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq, + unsigned int *unaccounted_time) { unsigned int slice_used; @@ -918,8 +919,13 @@ static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq) 1); } else { slice_used = jiffies - cfqq->slice_start; - if (slice_used > cfqq->allocated_slice) + if (slice_used > cfqq->allocated_slice) { + *unaccounted_time = slice_used - cfqq->allocated_slice; slice_used = cfqq->allocated_slice; + } + if (time_after(cfqq->slice_start, cfqq->dispatch_start)) + *unaccounted_time += cfqq->slice_start - + cfqq->dispatch_start; } return slice_used; @@ -929,12 +935,12 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg, struct cfq_queue *cfqq) { struct cfq_rb_root *st = &cfqd->grp_service_tree; - unsigned int used_sl, charge; + unsigned int used_sl, charge, unaccounted_sl = 0; int nr_sync = cfqg->nr_cfqq - cfqg_busy_async_queues(cfqd, cfqg) - cfqg->service_tree_idle.count; BUG_ON(nr_sync < 0); - used_sl = charge = cfq_cfqq_slice_usage(cfqq); + used_sl = charge = cfq_cfqq_slice_usage(cfqq, &unaccounted_sl); if (iops_mode(cfqd)) charge = cfqq->slice_dispatch; @@ -960,7 +966,8 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg, cfq_log_cfqq(cfqq->cfqd, cfqq, "sl_used=%u disp=%u charge=%u iops=%u" " sect=%u", used_sl, cfqq->slice_dispatch, charge, iops_mode(cfqd), cfqq->nr_sectors); - cfq_blkiocg_update_timeslice_used(&cfqg->blkg, used_sl); + cfq_blkiocg_update_timeslice_used(&cfqg->blkg, used_sl, + unaccounted_sl); cfq_blkiocg_set_start_empty_time(&cfqg->blkg); } @@ -3296,9 +3303,7 @@ static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) BUG_ON(!cfq_cfqq_on_rr(cfqq)); cfq_service_tree_add(cfqd, cfqq, 1); - - cfqq->slice_end = 0; - cfq_mark_cfqq_slice_new(cfqq); + __cfq_set_active_queue(cfqd, cfqq); } /* |