From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nix Subject: Re: batched write Date: Sun, 18 Jun 2006 12:20:00 +0100 Message-ID: <87ac8an21r.fsf@hades.wkstn.nix> References: <44736D3E.8090808@namesys.com> <20060524175312.GA3579@zero> <44749E24.40203@namesys.com> <20060608110044.GA5207@suse.de> <1149766000.6336.29.camel@tribesman.namesys.com> <20060608121006.GA8474@infradead.org> <1150322912.6322.129.camel@tribesman.namesys.com> <20060617100458.0be18073.akpm@osdl.org> <4494411B.4010706@namesys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andrew Morton , "Vladimir V. Saveliev" , hch@infradead.org, Reiserfs-Dev@namesys.com, Linux-Kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Return-path: Received: from 41-052.adsl.zetnet.co.uk ([194.247.41.52]:40708 "EHLO mail.esperi.org.uk") by vger.kernel.org with ESMTP id S1751147AbWFRLUp (ORCPT ); Sun, 18 Jun 2006 07:20:45 -0400 To: Hans Reiser In-Reply-To: <4494411B.4010706@namesys.com> (Hans Reiser's message of "17 Jun 2006 18:51:46 +0100") Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On 17 Jun 2006, Hans Reiser prattled cheerily: > If the FS is called per page, then it turns out that 3) costs more than > 1) and 2) for sophisticated filesystems. As we develop fancier and > fancier plugins this will just get more and more true. It decreases CPU > usage by 2x to use per sys_write calls into reiser4 rather than per page > calls into reiser4. This seems to me to be something that FUSE filesystems might well like, too: I know one I'm working on would like to know the real size of the original write request (so that it can optimize layout appropriately for things frequently written in large chunks; the assumption being that if it's written in large chunks it's likely to be read in large chunks too). -- `Voting for any American political party is fundamentally incomprehensible.' --- Vadik