lkml.org 
[lkml]   [2009]   [Jul]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 2/2] cfq-iosched: Do not disable idling for seeky processes if "fairness" is set
Date
o CFQ provides fair access to disk in terms of disk time used to processes.
Fairness is provided for the applications which have their think time with
in slice_idle (8ms default) limit.

o CFQ currently disables idling for seeky processes. So even if a process
has think time with-in slice_idle limits, it will still not get fair share
of disk. Disabling idling for a seeky process seems good from throughput
perspective but not necessarily from fairness perspecitve.

0 Do not disable idling based on seek pattern of process if a user has set
/sys/block/<disk>/queue/iosched/fairness = 1.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
block/cfq-iosched.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 658ea7b..9de8046 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1964,7 +1964,7 @@ cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq,
enable_idle = old_idle = cfq_cfqq_idle_window(cfqq);

if (!atomic_read(&cic->ioc->nr_tasks) || !cfqd->cfq_slice_idle ||
- (cfqd->hw_tag && CIC_SEEKY(cic)))
+ (!cfqd->cfq_fairness && cfqd->hw_tag && CIC_SEEKY(cic)))
enable_idle = 0;
else if (sample_valid(cic->ttime_samples)) {
if (cic->ttime_mean > cfqd->cfq_slice_idle)
--
1.6.0.6


\
 
 \ /
  Last update: 2009-07-12 21:01    [W:0.063 / U:0.176 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site