path: root/block
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authorCorrado Zoccolo <czoccolo@gmail.com>2009-11-26 09:41:21 +0100
committerJens Axboe <jens.axboe@oracle.com>2009-11-26 09:46:46 +0100
commitc16632bab1a17e357cec66920ceb3f0630009360 (patch)
tree6937755404314252f0bf2c46eec374c32c12f8b1 /block
parent2d4dc890b5c8fabd818a8586607e6843c4375e62 (diff)
cfq-iosched: cleanup unreachable code
cfq_should_idle returns false for no-idle queues that are not the last, so the control flow will never reach the removed code in a state that satisfies the if condition. The unreachable code was added to emulate previous cfq behaviour for non-NCQ rotational devices. My tests show that even without it, the performances and fairness are comparable with previous cfq, thanks to the fact that all seeky queues are grouped together, and that we idle at the end of the tree. Signed-off-by: Corrado Zoccolo <czoccolo@gmail.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block')
1 files changed, 0 insertions, 13 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 467981e19d7a..c2ef5d17608c 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1269,19 +1269,6 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd)
sl = cfqd->cfq_slice_idle;
- /* are we servicing noidle tree, and there are more queues?
- * non-rotational or NCQ: no idle
- * non-NCQ rotational : very small idle, to allow
- * fair distribution of slice time for a process doing back-to-back
- * seeks.
- */
- if (cfqd->serving_type == SYNC_NOIDLE_WORKLOAD &&
- service_tree_for(cfqd->serving_prio, SYNC_NOIDLE_WORKLOAD, cfqd)
- ->count > 0) {
- if (blk_queue_nonrot(cfqd->queue) || cfqd->hw_tag)
- return;
- sl = min(sl, msecs_to_jiffies(CFQ_MIN_TT));
- }
mod_timer(&cfqd->idle_slice_timer, jiffies + sl);
cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu", sl);