From: Tejun Heo <tj@kernel.org>
To: Jens Axboe <axboe@kernel.dk>
Cc: Hugh Dickins <hughd@google.com>,
Shaohua Li <shaohua.li@intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Stephen Rothwell <sfr@canb.auug.org.au>,
linux-next@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org,
x86@kernel.org
Subject: Re: [PATCH block/for-3.3/core] block: an exiting task should be allowed to create io_context
Date: Wed, 4 Jan 2012 17:24:45 -0800 [thread overview]
Message-ID: <20120105012445.GP31746@google.com> (raw)
In-Reply-To: <20120103223505.GI31746@google.com>
Hello, again.
On Tue, Jan 03, 2012 at 02:35:05PM -0800, Tejun Heo wrote:
> > Hmmm... I disabled cfqq merge logic (commented out
> > cfq_close_cooperator() and the following cfq_setup_merge() calls) in
> > cfq_select_queue() and neither is triggering for quite a while now.
> > Maybe cfqq refcnt is getting borked over cfqq merging / splitting? It
> > would also explain the low frequency of the issue too. I'll try to
> > further isolate it but It would be awesome if someone more familiar
> > with the logic can go over that part.
>
> Scrap that. It triggered and yeah cfq_get_next_queue() is retrieving
> empty cfqq from the service tree.
Update: I've been running with ELEVATOR_INSERT_SORT_MERGE disabled and
none of the issues triggered for about three hours now. It usually
triggers under an hour.
Hugh, can you please verify whether the patch appended at the end
makes the problem go away?
Thanks.
diff --git a/block/elevator.c b/block/elevator.c
index 99838f4..2e172d2 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -644,6 +644,9 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where)
rq->q = q;
+ if (where == ELEVATOR_INSERT_SORT_MERGE)
+ where = ELEVATOR_INSERT_SORT;
+
if (rq->cmd_flags & REQ_SOFTBARRIER) {
/* barriers are scheduling boundary, update end_sector */
if (rq->cmd_type == REQ_TYPE_FS ||
next prev parent reply other threads:[~2012-01-05 1:24 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-21 6:47 linux-next: Tree for Dec 21 Stephen Rothwell
2011-12-21 20:11 ` linux-next: Tree for Dec 21 (xen) Randy Dunlap
2011-12-21 19:30 ` Konrad Rzeszutek Wilk
2011-12-21 20:32 ` [PATCH] usb: fix renesas mod_gadget printk format warning Randy Dunlap
2011-12-21 21:16 ` Felipe Balbi
2011-12-21 22:19 ` Randy Dunlap
2011-12-21 21:24 ` Greg KH
2011-12-21 23:15 ` linux-next: Tree for Dec 21 Andrew Morton
2011-12-22 23:08 ` Andrew Morton
2011-12-22 23:20 ` Tejun Heo
2011-12-22 23:24 ` Andrew Morton
2011-12-22 23:38 ` Tejun Heo
2011-12-22 23:44 ` Andrew Morton
2011-12-22 23:46 ` Tejun Heo
2011-12-23 0:42 ` Tejun Heo
2011-12-24 5:13 ` Hugh Dickins
2011-12-25 1:02 ` [PATCH block/for-3.3/core] block: an exiting task should be allowed to create io_context Tejun Heo
2011-12-25 13:29 ` Jens Axboe
2011-12-27 22:07 ` Andrew Morton
2011-12-28 8:33 ` Hugh Dickins
2011-12-28 16:48 ` Tejun Heo
2011-12-28 17:50 ` Hugh Dickins
2011-12-28 17:55 ` Tejun Heo
2011-12-28 21:19 ` Tejun Heo
2012-01-03 17:35 ` Tejun Heo
2012-01-03 17:59 ` Tejun Heo
2012-01-03 20:09 ` Tejun Heo
2012-01-03 20:20 ` Jens Axboe
2012-01-03 22:13 ` Tejun Heo
2012-01-03 22:35 ` Tejun Heo
2012-01-05 1:24 ` Tejun Heo [this message]
2012-01-05 18:36 ` Hugh Dickins
2012-01-05 18:38 ` Tejun Heo
2012-01-06 2:17 ` [PATCH block:for-3.3/core] cfq: merged request shouldn't jump to a different cfqq Tejun Heo
2012-01-06 2:36 ` Tejun Heo
2012-01-06 3:14 ` Shaohua Li
2012-01-06 3:04 ` Tejun Heo
2012-01-06 3:30 ` Tejun Heo
2012-01-06 3:52 ` [PATCH block:for-3.3/core] block: disable ELEVATOR_INSERT_SORT_MERGE Tejun Heo
2012-01-06 4:19 ` Shaohua Li
2012-01-06 4:38 ` Tejun Heo
2012-01-06 8:15 ` Shaohua Li
2012-01-06 15:34 ` Tejun Heo
2012-01-06 3:34 ` [PATCH block:for-3.3/core] cfq: merged request shouldn't jump to a different cfqq Shaohua Li
2012-01-06 3:22 ` Tejun Heo
2012-01-06 4:15 ` Shaohua Li
2012-01-06 4:40 ` Tejun Heo
2012-01-06 2:47 ` Shaohua Li
2011-12-25 16:08 ` linux-next: Tree for Dec 21 Sedat Dilek
2011-12-25 23:55 ` Stephen Rothwell
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