linux-kernel - Re: [RFC PATCHSET] workqueue: implement concurrency managed 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:	Fri, 02 Oct 2009 20:44:58 +0900
From:	Tejun Heo <tj@...nel.org>
To:	David Howells <dhowells@...hat.com>
CC:	jeff@...zik.org, mingo@...e.hu, linux-kernel@...r.kernel.org,
	akpm@...ux-foundation.org, jens.axboe@...cle.com,
	rusty@...tcorp.com.au, cl@...ux-foundation.org,
	arjan@...ux.intel.com
Subject: Re: [RFC PATCHSET] workqueue: implement concurrency managed workqueue

Hello, David Howells.

David Howells wrote:
> Sounds interesting as a replacement for slow-work.  Some thoughts for you:
> 
> The most important features of slow-work are:
> 
>  (1) Work items are not re-entered whilst they are executing.
> 
>  (2) The slow-work facility keeps references on its work items by asking the
>      client to get and put on the client's refcount.
> 
>  (3) The slow-work facility can create a lot more threads than the number of
>      CPUs on a system, and the system doesn't grind to a halt if they're all
>      taken up with long term I/O (performing several mkdirs for example).
> 
> I think you have (1) and (3) covered, but I'm unsure about (2).

Given that slow-work isn't being used too extensively yet, I was
thinking whether that part could be pushed down to the caller.  Or, we
can also wrap work and export an interface which supports the get/put
reference.

> Also, does it actually make sense to bind threads that are
> performing long-term I/O to particular CPUs?  Threads that are going
> to spend a lot more time sleeping on disk I/O than actually running
> on a CPU?

Binding is usually beneficial and doesn't matter for IO intensive
ones, so...

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/