[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <200910072315.42047.czoccolo@gmail.com>
Date: Wed, 7 Oct 2009 23:15:41 +0200
From: Corrado Zoccolo <czoccolo@...il.com>
To: Jens Axboe <jens.axboe@...cle.com>
Cc: "Linux-Kernel" <linux-kernel@...r.kernel.org>,
Jeff Moyer <jmoyer@...hat.com>
Subject: [PATCH v2] cfq-iosched: avoid probable slice overrun when idling
Idle timer is not armed if remaining slice is less than average think
time.
Signed-off-by: Corrado Zoccolo <czoccolo@...il.com>
---
block/cfq-iosched.c | 8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index b35cc56..af1d621 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1099,6 +1099,14 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd)
if (!cic || !atomic_read(&cic->ioc->nr_tasks))
return;
+ /*
+ * think time is greater than remaining time slice
+ * don't idle, to avoid overrunnig the time slice
+ */
+ if (sample_valid(cic->ttime_samples) &&
+ (cfqq->slice_end - jiffies < cic->ttime_mean))
+ return;
+
cfq_mark_cfqq_wait_request(cfqq);
/*
--
1.6.2.5
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists