From: Jens Axboe <axboe@kernel.dk>
To: Dexuan Cui <decui@microsoft.com>,
"'ming.lei@redhat.com'" <ming.lei@redhat.com>,
'Christoph Hellwig' <hch@lst.de>,
"'linux-block@vger.kernel.org'" <linux-block@vger.kernel.org>
Cc: Long Li <longli@microsoft.com>,
"Michael Kelley (LINUX)" <mikelley@microsoft.com>,
"'linux-kernel@vger.kernel.org'" <linux-kernel@vger.kernel.org>
Subject: Re: Random high CPU utilization in blk-mq with the none scheduler
Date: Mon, 13 Dec 2021 11:43:02 -0700 [thread overview]
Message-ID: <bb696622-38ee-c582-ce70-5bfa632f8989@kernel.dk> (raw)
In-Reply-To: <BYAPR21MB1270C642C3200EC4E65C586EBF729@BYAPR21MB1270.namprd21.prod.outlook.com>
On 12/11/21 11:54 AM, Dexuan Cui wrote:
>> From: Jens Axboe <axboe@kernel.dk>
>> Sent: Saturday, December 11, 2021 6:21 AM
>>
>> Sorry, can you do:
>>
>> # perf report -g --no-children
>>
>> instead?
>
> Attached.
I wonder if this will help, SCSI artifact making us hit the
mod delayed work path all the time. Might be a race in there,
but should be fine for testing.
diff --git a/block/blk-core.c b/block/blk-core.c
index 4d8f5fe91588..cb2f4d604bad 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1625,7 +1625,9 @@ EXPORT_SYMBOL(kblockd_schedule_work);
int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork,
unsigned long delay)
{
- return mod_delayed_work_on(cpu, kblockd_workqueue, dwork, delay);
+ if (!work_pending(&dwork->work))
+ return mod_delayed_work_on(cpu, kblockd_workqueue, dwork, delay);
+ return true;
}
EXPORT_SYMBOL(kblockd_mod_delayed_work_on);
--
Jens Axboe
next prev parent reply other threads:[~2021-12-13 18:43 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-10 3:30 Random high CPU utilization in blk-mq with the none scheduler Dexuan Cui
2021-12-11 1:29 ` Dexuan Cui
2021-12-11 2:04 ` Jens Axboe
2021-12-11 3:10 ` Dexuan Cui
2021-12-11 3:15 ` Jens Axboe
2021-12-11 3:44 ` Dexuan Cui
2021-12-11 7:09 ` Dexuan Cui
2021-12-11 14:21 ` Jens Axboe
2021-12-11 18:54 ` Dexuan Cui
2021-12-13 18:43 ` Jens Axboe [this message]
2021-12-14 0:43 ` Dexuan Cui
2021-12-13 3:23 ` Ming Lei
2021-12-13 4:20 ` Dexuan Cui
2021-12-13 7:38 ` Ming Lei
2021-12-14 0:31 ` Dexuan Cui
2021-12-14 0:53 ` Ming Lei
2021-12-14 3:09 ` Dexuan Cui
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