[PATCH v2] cfq-iosched: convert group idle time to jiffies

From: Alexandru Moise
Date: Tue Dec 29 2015 - 15:17:06 EST


This patch refers to Jens Axboe's change way back in 2006:
7b14e3b52 cfq-iosched: slice expiry fixups

In this patch he fixed a potential timer race condition by delaying
idle_slice_timer by the slice_idle time value.

Today this timer is delayed by either slice_idle or group_idle time
values, which on my system, and according to
Documentation/block/cfq-iosched.txt the default value for group_idle
is 8ms.

Since the time given by group_idle is supposed to be in milliseconds
we should convert that value from milliseconds to jiffies before
adding it to jiffies variable and setting our timer.

Signed-off-by: Alexandru Moise <00moses.alexader00@xxxxxxxxx>
---
V2: slice_idle not in miliseconds, convert only group_idle

block/cfq-iosched.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 1f9093e..088c45d 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -2954,7 +2954,7 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd)
cfq_mark_cfqq_wait_request(cfqq);

if (group_idle)
- sl = cfqd->cfq_group_idle;
+ sl = msecs_to_jiffies(cfqd->cfq_group_idle);
else
sl = cfqd->cfq_slice_idle;

--
1.9.1

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