From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans Reiser Subject: Re: reiser4: first impression (vs xfs and jfs) Date: Fri, 09 Jun 2006 01:05:39 -0700 Message-ID: <44892BD3.5090604@namesys.com> References: <20060523155102.GB25889@zero> <20060606134459.GA18513@zero> <1149604706.6389.40.camel@tribesman.namesys.com> <20060606153035.GF10672@HAL_5000D> <4485D69B.1090608@namesys.com> <20060608140653.GA5851@zero> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: <20060608140653.GA5851@zero> List-Id: Content-Type: text/plain; charset="us-ascii" To: Tom Vier Cc: reiserfs-list@namesys.com Make both XFS or both reiser4, and speed will likely increase. Please try and report the result if you could. Tom Vier wrote: >On Tue, Jun 06, 2006 at 12:25:15PM -0700, Hans Reiser wrote: > > >>Maybe I should ask the following: is the slow drive using reiser4? If >> >> > >No, it was ext2. > > > >>reiser4, was the slow drive image created by copying from a reiser4 >>image or an ext3 image? (Standard benchmarking mistake: creating an >>image for a test from a filesystem not the one that is being tested. >>readdir order matters.) >> >> > >Would that really make much difference? > >I think the problem here is a general problem with delayed allocation, >regardless of which fs impliments it. The fs'es need to stream out writes. >If it's possible (i don't know if fs'es are allowed this info from the vfs), >i think after a short timeout of a file no longer being open for writing, it >should be written. Maybe have a longer delay for smaller files, so they pack >better. Past a certain size threshold, once a file is closed (or only opened >read-only) i think it should be flushes without much delay. Especially if >the blk dev is idle (but knowing that at the fs level may well be impossible >w/o modding the vfs api). I think linux (and other os'es) are in need of >more intelligent io scheduling (higher level than just sector elevators). > >One problem with my suggestion is that apps don't always close or reopen >read-only after they write a file. > > >