From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans Reiser Subject: Re: short term task list for Reiser4 Date: Tue, 11 Jul 2006 16:11:21 -0700 Message-ID: <44B43019.9010402@namesys.com> References: <44B42064.4070802@namesys.com> <20060711222903.GG9220@HAL_5000D.tc.ph.cox.net> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20060711222903.GG9220@HAL_5000D.tc.ph.cox.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: Content-Type: text/plain; charset="us-ascii" To: Clay Barnes Cc: Reiserfs mail-list , LKML , Alexander Lyamin aka FLX Clay Barnes wrote: >On 15:04 Tue 11 Jul , Hans Reiser wrote: > > >> >>6) optimize fsync --- substantive task which requires using fixed area >>for write twice logging, and using write twice logging for fsync'd >>data. It might require creating mount options to choose whether to >>optimize for serialized sequential fsyncs vs. lazy fsyncs. >> >> >With the serialized sequential fsync, is that essentially what I was >talking about earlier with slowly streaming dirty writes to disk when >the HDD is idle? If that's the case, I don't see the advantage in having >lazy fsyncs > if you are optimizing throughput rather than latency, then you let things get to disk whenever they get there, and you let the app hang while it waits. A mailer processing many requests in parallel might find 30 seconds of latency to be just fine but a database might find 3 seconds of latency to be too much. (I make up these examples, mailer programmers please correct me.) > except in situations where you want to keep the HDD spun down >as much as possible. > No, that is not when you do it. >I've been meaning to hose my laptop (assuming I fix one problem with my >desktop), so I am willing to help write Gentoo install docs (or possibly >Arch Linux). I can also test exsiting instructions. > > That would be way cool.