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From: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
To: Vivek Goyal <vgoyal@redhat.com>, Jens Axboe <axboe@kernel.dk>
Cc: lkml <linux-kernel@vger.kernel.org>
Subject: [PATCH] cfq-iosched: Fix update_vdisktime logic
Date: Tue, 25 Jan 2011 11:27:19 +0800	[thread overview]
Message-ID: <4D3E4317.80406@cn.fujitsu.com> (raw)

The update_vdisktime logic is broken since commit b54ce60eb7f61f8e314b8b241b0469eda3bb1d42,
st->min_vdisktime never makes a progress. Fix it.

Thanks Vivek for pointing it out.

Signed-off-by: Gui Jianfeng <guijianfen@cn.fujitsu.com>
---
 block/cfq-iosched.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index f083bda..8c28f56 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -558,15 +558,13 @@ static inline u64 min_vdisktime(u64 min_vdisktime, u64 vdisktime)
 
 static void update_min_vdisktime(struct cfq_rb_root *st)
 {
-	u64 vdisktime = st->min_vdisktime;
 	struct cfq_group *cfqg;
 
 	if (st->left) {
 		cfqg = rb_entry_cfqg(st->left);
-		vdisktime = min_vdisktime(vdisktime, cfqg->vdisktime);
+		st->min_vdisktime = max_vdisktime(st->min_vdisktime,
+						  cfqg->vdisktime);
 	}
-
-	st->min_vdisktime = max_vdisktime(st->min_vdisktime, vdisktime);
 }
 
 /*
-- 
1.7.1


             reply	other threads:[~2011-01-25  3:27 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-25  3:27 Gui Jianfeng [this message]
2011-01-25 21:26 ` [PATCH] cfq-iosched: Fix update_vdisktime logic Vivek Goyal
2011-03-07  1:35   ` Gui Jianfeng
2011-03-07  8:28     ` Jens Axboe

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