linux-kernel - Re: [PATCH] workqueue: Guarantee work function memory ordering

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20140222154135.GH12830@htj.dyndns.org>
Date:	Sat, 22 Feb 2014 10:41:35 -0500
From:	Tejun Heo <tj@...nel.org>
To:	Peter Hurley <peter@...leysoftware.com>
Cc:	Lai Jiangshan <laijs@...fujitsu.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] workqueue: Guarantee work function memory ordering

Hello, Peter.

On Sat, Feb 22, 2014 at 10:05:53AM -0500, Peter Hurley wrote:
> Given your concerns about the performance impact, maybe we should
> ask Fengguang to run this change through his automated test suites
> to find out what the perf delta is?

It should be fine.  It's more like I just didn't like the idea of it.
Workqueue execution path isn't really light enough for an addition of
single smp_rmb() per work item execution makes any noticeable
difference.  No harm in measuring perf delta but I'm highly skeptical
that there will be any difference which can be measured.

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/