Date: Sat, 22 Feb 2014 10:41:35 -0500
From: Tejun Heo <tj@kernel.org>
To: Peter Hurley <peter@hurleysoftware.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] workqueue: Guarantee work function memory ordering
Message-ID: <20140222154135.GH12830@htj.dyndns.org>
References: <1393071111-5128-1-git-send-email-peter@hurleysoftware.com>
 <20140222144010.GE12830@htj.dyndns.org>
 <5308BCD1.3070204@hurleysoftware.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <5308BCD1.3070204@hurleysoftware.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org

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@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/