RE: [PATCH] workqueue: doc change for ST behavior on NUMA systems

From: Alexei Potashnik
Date: Tue Jul 18 2017 - 17:32:41 EST


target has a bug in TMR handling.

dev->tmr_wq = alloc_workqueue("tmr-%s", WQ_MEM_RECLAIM |
WQ_UNBOUND, 1,
dev->transport->name);

LUN_RESET can race with TASK_ABORT in different sessions.
Will send a patch to target list.

-----Original Message-----
From: Christoph Hellwig [mailto:hch@xxxxxxxxxxxxx]
Sent: Tuesday, July 18, 2017 12:18 PM
To: Alexei Potashnik <alexei@xxxxxxxxxxxxxxx>
Cc: tj@xxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Subject: Re: [PATCH] workqueue: doc change for ST behavior on NUMA systems

On Tue, Jul 18, 2017 at 11:12:53AM -0700, Alexei Potashnik wrote:
> NUMA rework of workqueue made the combination of max_active of 1 and
> WQ_UNBOUND insufficient to guarantee ST behavior system wide.
>
> alloc_ordered_queue should now be used instead.

Eww. And how many existing users might be broken by that?