linux-kernel - Re: [PATCH] virtio_balloon: Convert "vballon" kthread into a workqueue

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sun, 28 Sep 2014 08:43:18 -0400
From:	Tejun Heo <tj@...nel.org>
To:	Petr Mladek <pmladek@...e.cz>
Cc:	Rusty Russell <rusty@...tcorp.com.au>,
	"Michael S. Tsirkin" <mst@...hat.com>,
	Jiri Kosina <jkosina@...e.cz>,
	virtualization@...ts.linux-foundation.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] virtio_balloon: Convert "vballon" kthread into a
 workqueue

On Thu, Sep 25, 2014 at 06:20:41PM +0200, Petr Mladek wrote:
...
>     1st create_freezable_workqueue("vballoon_wq");

All create_*workqueue() interfaces are deprecated.  Please don't
create new usages.  They map to alloc_*workqueue() anyway.

>     2nd alloc_workqueue("vballoon_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM, 0);

Is WQ_MEM_RECLAIM necessary here?  Does virtio_balloon depended upon
from memory allocation path?

...
> The 2nd way to create the workqueue has about the same results as kthread.
> This is why it is used in the patch.

You're testing WQ_UNBOUND vs. !WQ_UNBOUND and yes for most use cases,
!WQ_UNBOUND will be more efficient.  The right thing to do in most
cases is using alloc_workqueue() w/ as minimum extra flags as
possible.

Thanks!

-- 
tejun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/