From owner-freebsd-current@FreeBSD.ORG Wed Nov 7 22:23:13 2007 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3B11B16A417 for ; Wed, 7 Nov 2007 22:23:13 +0000 (UTC) (envelope-from arne_woerner@yahoo.com) Received: from web30309.mail.mud.yahoo.com (web30309.mail.mud.yahoo.com [209.191.69.71]) by mx1.freebsd.org (Postfix) with SMTP id D5E8713C4A5 for ; Wed, 7 Nov 2007 22:23:11 +0000 (UTC) (envelope-from arne_woerner@yahoo.com) Received: (qmail 34547 invoked by uid 60001); 7 Nov 2007 22:16:20 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding:Message-ID; b=ttB7Jq5m/n2mZSraHBX4g2Hu+kMeOuvLcW0u9GB3+nhC1XsgKZFxOSOJlFk841n2Ov/R7DqJBKJm9+frecTHv49MrYfdOdN1gu18sX/gHx1/dcMipSj2NTv8yyYN6IUiDnloqubFTs4mRr13Qv9KwOgI+A5kn/CBP1zG9piaNwg=; X-YMail-OSG: yCdck3YVM1mFIE8Cx3UGiS8bf4N5sk10z5FdMeGFKM8GfQq5znBfXsAnmIP5fyzlQvczwl.e5PGl145WtMTS9.k8RoV47gnukuyeTw7kI8B2sW_H_FI5TGOybg-- Received: from [84.141.120.234] by web30309.mail.mud.yahoo.com via HTTP; Wed, 07 Nov 2007 14:16:20 PST Date: Wed, 7 Nov 2007 14:16:20 -0800 (PST) From: Arne "Wörner" To: Ulf Lilleengen , Arne@stud.ntnu.no, W@stud.ntnu.no In-Reply-To: <20071107210635.GA12736@stud.ntnu.no> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Message-ID: <613458.33465.qm@web30309.mail.mud.yahoo.com> Cc: John Nielsen , freebsd-current@freebsd.org, "fluffles.net" Subject: Re: geom_raid5 inclusion in HEAD? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 07 Nov 2007 22:23:13 -0000 --- Ulf Lilleengen wrote: > - Parantheses around return values: > Hmm... OK... I can do that, although "return" is no function... It feels more like an operator for me (like "=" or "++")... But if we want to do it that way, it is OK... > - Proper indenting when breaking a line, should be 4 spaces etc. > Ohoh... I always tried to use tabs... > All of this can be found in the style(9) manpage, so I'd rather just suggest > to go through it and make sure it's satisfied. > Hmm... Ooch... > I've only looked at TOS so far, but I'll look at PP as well to see how it is. > I have uploaded a PP version now, that has some explanations for each function or group of similar functions respectively... > > Hmm... if I understood correctly, FreeBSD's kernel memory suffers under > > fragmentation, if many big mem areas r needed... There might be even a dead > > lock, if UFS uses 64kb block size... So I thought it would be a good idea > to > > avoid those sleeps but "hamster-ing" the big chunks... :) But I am not sure > > anymore, that it improved performance (but performance was the reason for > > it)... > Hmm, I'm not sure what you mean about this dead lock, but sounds like a weird > thing to having to deadlock because of your filesystem. Maybe this could be > solved in another way, or is this not a graid5-thing at all? > It seems to be general problem with kernel and/or VFS memory... U can provoke it with heavy UFS access with several bonnie processes and UFS-block-size of 64kB... > The general thing is that I don't think one should start optimizing for > performance before everything works correctly and having made sure that it > improves performance statistically. (I know this isn't a completely new > project, but still). > Yup... And it's a little bit selfish to hamster memory... > First of all, disk I/O is generally much slower than CPU anyway, so I would > doubt that having to use one thread would decrease performance noticeably. > In my ears, this is a good argument for using one thread only. But then > again, this might not be a big deal if it's already there and it's correct. > Hmm... Yup... But reducing short delays (like for bcopy) increased throughput significantly (IIRC)... > I'm starting to get busier and busier with exams coming up now, but I'll try > take a look when I can, but don't expect to much :) Also, as I said, I've > only looked at TOS so far. > OK - I cannot spend so much time for this, too... I have a backlog of more than 10 hours of "important" TV series... :-) -Arne __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com