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-rw-r--r--block/blk-throttle.c10
-rw-r--r--block/cfq-iosched.c10
2 files changed, 16 insertions, 4 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 381b09bb562..a89043a3caa 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -168,7 +168,15 @@ static struct throtl_grp * throtl_find_alloc_tg(struct throtl_data *td,
* tree of blkg (instead of traversing through hash list all
* the time.
*/
- tg = tg_of_blkg(blkiocg_lookup_group(blkcg, key));
+
+ /*
+ * This is the common case when there are no blkio cgroups.
+ * Avoid lookup in this case
+ */
+ if (blkcg == &blkio_root_cgroup)
+ tg = &td->root_tg;
+ else
+ tg = tg_of_blkg(blkiocg_lookup_group(blkcg, key));
/* Fill in device details for root group */
if (tg && !tg->blkg.dev && bdi->dev && dev_name(bdi->dev)) {
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 501ffdf0399..7be4c795962 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -599,7 +599,7 @@ cfq_group_slice(struct cfq_data *cfqd, struct cfq_group *cfqg)
}
static inline unsigned
-cfq_scaled_group_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+cfq_scaled_cfqq_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
unsigned slice = cfq_prio_to_slice(cfqd, cfqq);
if (cfqd->cfq_latency) {
@@ -631,7 +631,7 @@ cfq_scaled_group_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
static inline void
cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
- unsigned slice = cfq_scaled_group_slice(cfqd, cfqq);
+ unsigned slice = cfq_scaled_cfqq_slice(cfqd, cfqq);
cfqq->slice_start = jiffies;
cfqq->slice_end = jiffies + slice;
@@ -1671,7 +1671,7 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq,
*/
if (timed_out) {
if (cfq_cfqq_slice_new(cfqq))
- cfqq->slice_resid = cfq_scaled_group_slice(cfqd, cfqq);
+ cfqq->slice_resid = cfq_scaled_cfqq_slice(cfqd, cfqq);
else
cfqq->slice_resid = cfqq->slice_end - jiffies;
cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid);
@@ -3432,6 +3432,10 @@ static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
struct cfq_io_context *cic = cfqd->active_cic;
+ /* If the queue already has requests, don't wait */
+ if (!RB_EMPTY_ROOT(&cfqq->sort_list))
+ return false;
+
/* If there are other queues in the group, don't wait */
if (cfqq->cfqg->nr_cfqq > 1)
return false;