path: root/block
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authorVivek Goyal <vgoyal@redhat.com>2009-12-03 12:59:56 -0500
committerJens Axboe <jens.axboe@oracle.com>2009-12-03 19:28:53 +0100
commitc04645e592d4dd60c58def40c913699d4c806727 (patch)
tree61e2b6fac3c9dd0f211c07f024fe5cb17ff5d3cf /block
parentae30c286553c91c49af5cbc0265a05a6543d0c52 (diff)
blkio: Wait on sync-noidle queue even if rq_noidle = 1
o rq_noidle() is supposed to tell cfq that do not expect a request after this one, hence don't idle. But this does not seem to work very well. For example for direct random readers, rq_noidle = 1 but there is next request coming after this. Not idling, leads to a group not getting its share even if group_isolation=1. o The right solution for this issue is to scan the higher layers and set right flag (WRITE_SYNC or WRITE_ODIRECT). For the time being, this single line fix helps. This should not have any significant impact when we are not using cgroups. I will later figure out IO paths in higher layer and fix it. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block')
1 files changed, 2 insertions, 1 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 063dcbb714e7..08b057b1b3b2 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -3314,7 +3314,8 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
* only if we processed at least one !rq_noidle request
if (cfqd->serving_type == SYNC_WORKLOAD
- || cfqd->noidle_tree_requires_idle)
+ || cfqd->noidle_tree_requires_idle
+ || cfqq->cfqg->nr_cfqq == 1)