[PATCH] cfq-iosched: fix think time allowed for seekers

From: Corrado Zoccolo
Date: Wed Oct 07 2009 - 05:01:46 EST


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@xxxxxxxxx>
---
block/cfq-iosched.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 55bb8ca..4c795a2 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1997,7 +1997,10 @@ 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;
--
1.6.2.5


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