From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans Reiser Subject: Re: batched write Date: Mon, 19 Jun 2006 09:39:43 -0700 Message-ID: <4496D34F.4010007@namesys.com> 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> <87ac8an21r.fsf@hades.wkstn.nix> <449668D1.1050200@namesys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: nix@esperi.org.uk, akpm@osdl.org, vs@namesys.com, hch@infradead.org, Reiserfs-Dev@namesys.com, Linux-Kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, drepper@redhat.com Return-path: Received: from rwcrmhc14.comcast.net ([204.127.192.84]:40680 "EHLO rwcrmhc14.comcast.net") by vger.kernel.org with ESMTP id S964791AbWFSQjr (ORCPT ); Mon, 19 Jun 2006 12:39:47 -0400 To: Miklos Szeredi In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Miklos Szeredi wrote: >>Forgive myn utter ignorance of fuse, but does it currently context >>switch to user space for every 4k written through VFS? >> >> > >Yes, unfortunately it does, so fuse would benefit from batched writing >as well, with some constraint on the number of locked pages to avoid >DoS against the page cache. > >Miklos > > > > I would think that batched write is pretty essential then to FUSE performance. If we could then get the glibc authors to not sabotage the using of a large block size to indicate that we like large IOs (see thread on fseek implementation), reiser4 and FUSE would be all set for improved performance. Even without glibc developer cooperation, we will get a lot of benefits.