Messages in this thread Patch in this message | | | Date | Tue, 08 Dec 2009 15:43:41 +0800 | From | Gui Jianfeng <> | Subject | [PATCH] cfq: Optimization for close cooperating queue searching |
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It doesn't make any sense to try to find out a close cooperating queue if current cfqq is the only one in the group.
Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com> --- block/cfq-iosched.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index cfb0b2f..89b5dd9 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -1750,6 +1750,12 @@ static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, return NULL; /* + * Don't search priority tree if it's the only queue in the group. + */ + if (cur_cfqq->cfqg->nr_cfqq == 1) + return NULL; + + /* * We should notice if some of the queues are cooperating, eg * working closely on the same area of the disk. In that case, * we can group them together and don't waste time idling. -- 1.5.4.rc3
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