From owner-freebsd-geom@FreeBSD.ORG Wed Jul 5 17:50:20 2006 Return-Path: X-Original-To: freebsd-geom@freebsd.org Delivered-To: freebsd-geom@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 303F116A505 for ; Wed, 5 Jul 2006 17:50:20 +0000 (UTC) (envelope-from anderson@centtech.com) Received: from mh2.centtech.com (moat3.centtech.com [207.200.51.50]) by mx1.FreeBSD.org (Postfix) with ESMTP id 714D243D5E for ; Wed, 5 Jul 2006 17:50:11 +0000 (GMT) (envelope-from anderson@centtech.com) Received: from [10.177.171.220] (neutrino.centtech.com [10.177.171.220]) by mh2.centtech.com (8.13.1/8.13.1) with ESMTP id k65HoAok095917; Wed, 5 Jul 2006 12:50:10 -0500 (CDT) (envelope-from anderson@centtech.com) Message-ID: <44ABFBD5.5020705@centtech.com> Date: Wed, 05 Jul 2006 12:50:13 -0500 From: Eric Anderson User-Agent: Thunderbird 1.5.0.4 (X11/20060612) MIME-Version: 1.0 To: "R. B. Riddick" References: <20060704200124.25467.qmail@web30301.mail.mud.yahoo.com> In-Reply-To: <20060704200124.25467.qmail@web30301.mail.mud.yahoo.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: ClamAV 0.87.1/1585/Tue Jul 4 15:39:34 2006 on mh2.centtech.com X-Virus-Status: Clean Cc: freebsd-geom@freebsd.org Subject: Re: new class / geom_cache / request for comments X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 05 Jul 2006 17:50:20 -0000 R. B. Riddick wrote: > Hiho! > > I just wrote a new(?) GEOM class: > geom_cache > > It is my very first GEOM class and my first larger kernel code... > I took it mostly from geom_concat... :-) > It was quite easy to change the behaviour of geom_concat... > > The advantage of geom_cache is, that (even if we have a hard disc with a cache) > we can avoid reading the same area twice. I cared for segmentation of the cache > space a little bit by using a stripe size. The cache is always clean > (hopefully), so that it should not be dangerous to use geom_cache (if I did > everything right enough). > > I attached a bzip'ed tar file although it is about 15KB large. > > I would be glad, > 1. if somebody tells me, what I did wrong (especially that license stuff and > the man page (I dont know man page language) might be wrong) > and > 2. if somebody can use it. > > I plan to use it for my next GEOM class (geom_raid5), where it might be useful > in case of sequential read from a degraded provider (or is there a smarter way > to do it?). > > Bye > Arne Hi Arne! Just curious, how is this different/better than the regular buffer cache? Eric -- ------------------------------------------------------------------------ Eric Anderson Sr. Systems Administrator Centaur Technology Anything that works is better than anything that doesn't. ------------------------------------------------------------------------