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-rw-r--r--block/cfq-iosched.c22
1 files changed, 21 insertions, 1 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 4e5978426ee7..d227ad633242 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -141,7 +141,7 @@ struct cfq_queue {
/* io prio of this group */
unsigned short ioprio, org_ioprio;
- unsigned short ioprio_class;
+ unsigned short ioprio_class, org_ioprio_class;
pid_t pid;
@@ -3700,6 +3700,7 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq, struct cfq_io_cq *cic)
* elevate the priority of this queue
*/
cfqq->org_ioprio = cfqq->ioprio;
+ cfqq->org_ioprio_class = cfqq->ioprio_class;
cfq_clear_cfqq_prio_changed(cfqq);
}
@@ -4295,6 +4296,24 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
cfq_schedule_dispatch(cfqd);
}
+static void cfqq_boost_on_prio(struct cfq_queue *cfqq, int op_flags)
+{
+ /*
+ * If REQ_PRIO is set, boost class and prio level, if it's below
+ * BE/NORM. If prio is not set, restore the potentially boosted
+ * class/prio level.
+ */
+ if (!(op_flags & REQ_PRIO)) {
+ cfqq->ioprio_class = cfqq->org_ioprio_class;
+ cfqq->ioprio = cfqq->org_ioprio;
+ } else {
+ if (cfq_class_idle(cfqq))
+ cfqq->ioprio_class = IOPRIO_CLASS_BE;
+ if (cfqq->ioprio > IOPRIO_NORM)
+ cfqq->ioprio = IOPRIO_NORM;
+ }
+}
+
static inline int __cfq_may_queue(struct cfq_queue *cfqq)
{
if (cfq_cfqq_wait_request(cfqq) && !cfq_cfqq_must_alloc_slice(cfqq)) {
@@ -4325,6 +4344,7 @@ static int cfq_may_queue(struct request_queue *q, int op, int op_flags)
cfqq = cic_to_cfqq(cic, rw_is_sync(op, op_flags));
if (cfqq) {
cfq_init_prio_data(cfqq, cic);
+ cfqq_boost_on_prio(cfqq, op_flags);
return __cfq_may_queue(cfqq);
}