---

yaml
---
r: 172975
b: refs/heads/master
c: 76280af
h: refs/heads/master
i:
  172973: 1f764c0
  172971: c680783
  172967: e2fecbe
  172959: 6685012
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e4a229196a7c676514c78f6783f8994f64bf681c
+refs/heads/master: 76280aff1c7e9ae761cac4b48591c43cd7d69159

trunk/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);