1 files changed, 12 insertions, 1 deletions

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 2c1086acddfa..15f7238f527f 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -260,6 +260,7 @@ enum cfqq_state_flags {
         CFQ_CFQQ_FLAG_slice_new,        /* no requests dispatched in slice */
         CFQ_CFQQ_FLAG_sync,             /* synchronous queue */
         CFQ_CFQQ_FLAG_coop,             /* cfqq is shared */
+        CFQ_CFQQ_FLAG_deep,             /* sync cfqq experienced large depth */
 };
 
 #define CFQ_CFQQ_FNS(name)                                              \
@@ -286,6 +287,7 @@ CFQ_CFQQ_FNS(prio_changed);
 CFQ_CFQQ_FNS(slice_new);
 CFQ_CFQQ_FNS(sync);
 CFQ_CFQQ_FNS(coop);
+CFQ_CFQQ_FNS(deep);
 #undef CFQ_CFQQ_FNS
 
 #define cfq_log_cfqq(cfqd, cfqq, fmt, args...)  \
@@ -2350,8 +2352,12 @@ cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 
         enable_idle = old_idle = cfq_cfqq_idle_window(cfqq);
 
+        if (cfqq->queued[0] + cfqq->queued[1] >= 4)
+                cfq_mark_cfqq_deep(cfqq);
+
         if (!atomic_read(&cic->ioc->nr_tasks) || !cfqd->cfq_slice_idle ||
-            (sample_valid(cfqq->seek_samples) && CFQQ_SEEKY(cfqq)))
+            (!cfq_cfqq_deep(cfqq) && sample_valid(cfqq->seek_samples)
+             && CFQQ_SEEKY(cfqq)))
                 enable_idle = 0;
         else if (sample_valid(cic->ttime_samples)) {
                 if (cic->ttime_mean > cfqd->cfq_slice_idle)
@@ -2849,6 +2855,11 @@ static void cfq_idle_slice_timer(unsigned long data)
                  */
                 if (!RB_EMPTY_ROOT(&cfqq->sort_list))
                         goto out_kick;
+
+                /*
+                 * Queue depth flag is reset only when the idle didn't succeed
+                 */
+                cfq_clear_cfqq_deep(cfqq);
         }
 expire:
         cfq_slice_expired(cfqd, timed_out);