From mboxrd@z Thu Jan  1 00:00:00 1970
From: Artem Bityutskiy <dedekind1@gmail.com>
Subject: Re: [PATCHv2 11/11] writeback: prevent unnecessary bdi threads
 wakeups
Date: Thu, 22 Jul 2010 12:24:13 +0300
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Cc: Dave Chinner <david@fromorbit.com>,
	Dave Chinner <dchinner@redhat.com>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	Jens Axboe <axboe@kernel.dk>
To: Christoph Hellwig <hch@infradead.org>
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <20100722090023.GA7692@infradead.org>
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List-Id: linux-fsdevel.vger.kernel.org

On Thu, 2010-07-22 at 05:00 -0400, Christoph Hellwig wrote:
> 	 if (wakeup_bdi) {
> 	 	spin_lock(&bdi->wb_lock);
> 		if (bdi->wb.task) {
> 			trace_writeback_wake_thread(bdi);
> 			wake_up_process(bdi->wb.task);
> 		} else {
> 			trace_writeback_wake_forker_thread(bdi);
> 			wake_up_process(default_backing_dev_info.wb.task);
> 		}
> 		spin_unlock(&bdi->wb_lock);
> 	}

Side note: I've noticed you've made the optimistic "if" condition first=
,
which is better, and I'll also amend this in v3.

--=20
Best Regards,
Artem Bityutskiy (=D0=90=D1=80=D1=82=D1=91=D0=BC =D0=91=D0=B8=D1=82=D1=8E=
=D1=86=D0=BA=D0=B8=D0=B9)