Re: [RFC PATCH 0/3] block: Fix fsync slowness with CFQ cgroups

From: Konstantin Khlebnikov
Date: Tue Jun 28 2011 - 07:03:38 EST


Vivek Goyal wrote:
This patch series seems to be working for me. I did testing for ext4 only.
This series is based on for-3.1/core branch of Jen's block tree.
Konstantin, can you please give it a try and see if it fixes your
issue.

It works for me too, for ext3 and ext4, on top 3.0-rc5, after these trivial fixes:

--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1511,7 +1519,7 @@ static void cfq_add_rq_rb(struct request *rq)
* if that happens, put the alias on the dispatch list
*/
while ((__alias = elv_rb_add(&cfqq->sort_list, rq)) != NULL)
- cfq_dispatch_insert(cfqd->queue, __alias);
+ cfq_dispatch_insert(cfqd->queue, __alias, false);

if (!cfq_cfqq_on_rr(cfqq))
cfq_add_cfqq_rr(cfqd, cfqq);
@@ -3797,12 +3797,11 @@ cfq_set_depends_on_task(struct request_queue *q, struct task_struct *tsk)
*/
rcu_read_lock();
if (task_blkio_cgroup(current) == task_blkio_cgroup(tsk))
- return;
- rcu_read_unlock();
+ goto out_unlock_rcu;

cic = cfq_cic_lookup(cfqd, current->io_context);
if (!cic)
- return;
+ goto out_unlock_rcu;

task_lock(tsk);
spin_lock_irq(q->queue_lock);
@@ -3847,6 +3846,8 @@ cfq_set_depends_on_task(struct request_queue *q, struct task_struct *tsk)
out_unlock:
spin_unlock_irq(q->queue_lock);
task_unlock(tsk);
+out_unlock_rcu:
+ rcu_read_unlock();
}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/