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-rw-r--r--block/blk-cgroup.c15
-rw-r--r--block/blk-cgroup.h5
-rw-r--r--block/cfq-iosched.c33
3 files changed, 27 insertions, 26 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 83930f65016a..af42efbb0c1d 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -213,7 +213,7 @@ void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg)
}
EXPORT_SYMBOL_GPL(blkiocg_update_avg_queue_size_stats);
-void blkiocg_set_start_empty_time(struct blkio_group *blkg, bool ignore)
+void blkiocg_set_start_empty_time(struct blkio_group *blkg)
{
unsigned long flags;
struct blkio_group_stats *stats;
@@ -228,12 +228,15 @@ void blkiocg_set_start_empty_time(struct blkio_group *blkg, bool ignore)
}
/*
- * If ignore is set, we do not panic on the empty flag being set
- * already. This is to avoid cases where there are superfluous timeslice
- * complete events (for eg., forced_dispatch in CFQ) when no IOs are
- * served which could result in triggering the empty check incorrectly.
+ * group is already marked empty. This can happen if cfqq got new
+ * request in parent group and moved to this group while being added
+ * to service tree. Just ignore the event and move on.
*/
- BUG_ON(!ignore && blkio_blkg_empty(stats));
+ if(blkio_blkg_empty(stats)) {
+ spin_unlock_irqrestore(&blkg->stats_lock, flags);
+ return;
+ }
+
stats->start_empty_time = sched_clock();
blkio_mark_blkg_empty(stats);
spin_unlock_irqrestore(&blkg->stats_lock, flags);
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 2c956a06339a..a491a6d56ecf 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -174,7 +174,7 @@ void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
unsigned long dequeue);
void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
void blkiocg_update_idle_time_stats(struct blkio_group *blkg);
-void blkiocg_set_start_empty_time(struct blkio_group *blkg, bool ignore);
+void blkiocg_set_start_empty_time(struct blkio_group *blkg);
#define BLKG_FLAG_FNS(name) \
static inline void blkio_mark_blkg_##name( \
@@ -205,8 +205,7 @@ static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
{}
static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {}
-static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg,
- bool ignore) {}
+static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
#endif
#if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index d5927b53020e..002a5b621653 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -888,7 +888,7 @@ static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq)
}
static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg,
- struct cfq_queue *cfqq, bool forced)
+ struct cfq_queue *cfqq)
{
struct cfq_rb_root *st = &cfqd->grp_service_tree;
unsigned int used_sl, charge_sl;
@@ -918,7 +918,7 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg,
cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime,
st->min_vdisktime);
blkiocg_update_timeslice_used(&cfqg->blkg, used_sl);
- blkiocg_set_start_empty_time(&cfqg->blkg, forced);
+ blkiocg_set_start_empty_time(&cfqg->blkg);
}
#ifdef CONFIG_CFQ_GROUP_IOSCHED
@@ -1582,7 +1582,7 @@ static void __cfq_set_active_queue(struct cfq_data *cfqd,
*/
static void
__cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq,
- bool timed_out, bool forced)
+ bool timed_out)
{
cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out);
@@ -1609,7 +1609,7 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq,
cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid);
}
- cfq_group_served(cfqd, cfqq->cfqg, cfqq, forced);
+ cfq_group_served(cfqd, cfqq->cfqg, cfqq);
if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list))
cfq_del_cfqq_rr(cfqd, cfqq);
@@ -1628,13 +1628,12 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq,
}
}
-static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out,
- bool forced)
+static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out)
{
struct cfq_queue *cfqq = cfqd->active_queue;
if (cfqq)
- __cfq_slice_expired(cfqd, cfqq, timed_out, forced);
+ __cfq_slice_expired(cfqd, cfqq, timed_out);
}
/*
@@ -2202,7 +2201,7 @@ static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd)
}
expire:
- cfq_slice_expired(cfqd, 0, false);
+ cfq_slice_expired(cfqd, 0);
new_queue:
/*
* Current queue expired. Check if we have to switch to a new
@@ -2228,7 +2227,7 @@ static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq)
BUG_ON(!list_empty(&cfqq->fifo));
/* By default cfqq is not expired if it is empty. Do it explicitly */
- __cfq_slice_expired(cfqq->cfqd, cfqq, 0, true);
+ __cfq_slice_expired(cfqq->cfqd, cfqq, 0);
return dispatched;
}
@@ -2242,7 +2241,7 @@ static int cfq_forced_dispatch(struct cfq_data *cfqd)
int dispatched = 0;
/* Expire the timeslice of the current active queue first */
- cfq_slice_expired(cfqd, 0, true);
+ cfq_slice_expired(cfqd, 0);
while ((cfqq = cfq_get_next_queue_forced(cfqd)) != NULL) {
__cfq_set_active_queue(cfqd, cfqq);
dispatched += __cfq_forced_dispatch_cfqq(cfqq);
@@ -2411,7 +2410,7 @@ static int cfq_dispatch_requests(struct request_queue *q, int force)
cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) ||
cfq_class_idle(cfqq))) {
cfqq->slice_end = jiffies + 1;
- cfq_slice_expired(cfqd, 0, false);
+ cfq_slice_expired(cfqd, 0);
}
cfq_log_cfqq(cfqd, cfqq, "dispatched a request");
@@ -2442,7 +2441,7 @@ static void cfq_put_queue(struct cfq_queue *cfqq)
orig_cfqg = cfqq->orig_cfqg;
if (unlikely(cfqd->active_queue == cfqq)) {
- __cfq_slice_expired(cfqd, cfqq, 0, false);
+ __cfq_slice_expired(cfqd, cfqq, 0);
cfq_schedule_dispatch(cfqd);
}
@@ -2543,7 +2542,7 @@ static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
struct cfq_queue *__cfqq, *next;
if (unlikely(cfqq == cfqd->active_queue)) {
- __cfq_slice_expired(cfqd, cfqq, 0, false);
+ __cfq_slice_expired(cfqd, cfqq, 0);
cfq_schedule_dispatch(cfqd);
}
@@ -3172,7 +3171,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
cfq_log_cfqq(cfqd, cfqq, "preempt");
- cfq_slice_expired(cfqd, 1, false);
+ cfq_slice_expired(cfqd, 1);
/*
* Put the new queue at the front of the of the current list,
@@ -3383,7 +3382,7 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
* - when there is a close cooperator
*/
if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq))
- cfq_slice_expired(cfqd, 1, false);
+ cfq_slice_expired(cfqd, 1);
else if (sync && cfqq_empty &&
!cfq_close_cooperator(cfqd, cfqq)) {
cfqd->noidle_tree_requires_idle |= !rq_noidle(rq);
@@ -3648,7 +3647,7 @@ static void cfq_idle_slice_timer(unsigned long data)
cfq_clear_cfqq_deep(cfqq);
}
expire:
- cfq_slice_expired(cfqd, timed_out, false);
+ cfq_slice_expired(cfqd, timed_out);
out_kick:
cfq_schedule_dispatch(cfqd);
out_cont:
@@ -3691,7 +3690,7 @@ static void cfq_exit_queue(struct elevator_queue *e)
spin_lock_irq(q->queue_lock);
if (cfqd->active_queue)
- __cfq_slice_expired(cfqd, cfqd->active_queue, 0, false);
+ __cfq_slice_expired(cfqd, cfqd->active_queue, 0);
while (!list_empty(&cfqd->cic_list)) {
struct cfq_io_context *cic = list_entry(cfqd->cic_list.next,