From: Corrado Zoccolo <czoccolo@gmail.com>
Date: Wed, 7 Oct 2009 17:51:54 +0000 (+0200)
Subject: cfq-iosched: fix think time allowed for seekers
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=ec60e4f6749daf535329dac571293cf19c627aff;p=deliverable%2Flinux.git

cfq-iosched: fix think time allowed for seekers

CFQ enables idle only for processes that think less than the allowed
idle time. Since idle time is lower for seeky queues, we should use the
correct value in the comparison.

Signed-off-by: Corrado Zoccolo <czoccolo@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 4ab33d8a20b2..b35cc56dfd94 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1995,7 +1995,10 @@ cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 	    (!cfqd->cfq_latency && cfqd->hw_tag && CIC_SEEKY(cic)))
 		enable_idle = 0;
 	else if (sample_valid(cic->ttime_samples)) {
-		if (cic->ttime_mean > cfqd->cfq_slice_idle)
+		unsigned int slice_idle = cfqd->cfq_slice_idle;
+		if (sample_valid(cic->seek_samples) && CIC_SEEKY(cic))
+			slice_idle = msecs_to_jiffies(CFQ_MIN_TT);
+		if (cic->ttime_mean > slice_idle)
 			enable_idle = 0;
 		else
 			enable_idle = 1;