From mboxrd@z Thu Jan 1 00:00:00 1970 From: Artem Bityutskiy Subject: Re: [PATCHv4 12/14] writeback: optimize periodic bdi thread wakeups Date: Sat, 24 Jul 2010 09:00:08 +0300 Message-ID: <1279951208.4655.5.camel@localhost> References: <1279897554-1526-1-git-send-email-dedekind1@gmail.com> <1279897554-1526-13-git-send-email-dedekind1@gmail.com> <20100723162800.GB29633@infradead.org> Reply-To: dedekind1@gmail.com Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Jens Axboe , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org To: Christoph Hellwig Return-path: In-Reply-To: <20100723162800.GB29633@infradead.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Fri, 2010-07-23 at 12:28 -0400, Christoph Hellwig wrote: > I haven't reviewed this in detail, but what ensures the timer is > synchronously removed when the forker goes away? Good point, thanks. > I don't see a > del_timer_sync call anywhere. For now it might be easier to just > skip this patch and leave it for later. Well, my tests showed that with this patch the flushers wake up considerably less. So I'll try to come up with a better patch. I will set-up better testing. Will hack things so that the background dirty writeout timeout is something like 1-3 jiffies and the bdi thread inactive timeout is something like 3-5 jiffies. Then will write a scrip= t which forks many tasks each of each creates a loop-back device, mounts it, does some I/O, unmounts, removes the loop-back device, and so on. I= f run for long time, it should give good stress to the code paths I'm working on. I have a 2-way 4-core (total 8) amd64 testbox to test. --=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)