path: root/block
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authorDivyesh Shah <dpshah@google.com>2010-03-25 15:45:57 +0100
committerJens Axboe <jens.axboe@oracle.com>2010-03-25 15:46:38 +0100
commit39c01b219fd30c74869b6fc8749f7900f04e9ef6 (patch)
tree7ce59210c28e2b53daf2957174d3ae164701b181 /block
parentcfq-iosched: Add additional blktrace log messages in CFQ for easier debugging (diff)
cfq-iosched: Do not merge queues of BE and IDLE classes
Even if they are found to be co-operating. The prio_trees do not have any IDLE cfqqs on them. cfq_close_cooperator() is called from cfq_select_queue() and cfq_completed_request(). The latter ensures that the close cooperator code does not get invoked if the current cfqq is of class IDLE but the former doesn't seem to have any such checks. So an IDLE cfqq may get merged with a BE cfqq from the same group which should be avoided. Signed-off-by: Divyesh Shah<dpshah@google.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block')
1 files changed, 2 insertions, 0 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 2f91c5351949..2c7a0f4f3cd7 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1723,6 +1723,8 @@ static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd,
struct cfq_queue *cfqq;
+ if (cfq_class_idle(cur_cfqq))
+ return NULL;
if (!cfq_cfqq_sync(cur_cfqq))
return NULL;
if (CFQQ_SEEKY(cur_cfqq))