From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262473AbVGLVn7 (ORCPT ); Tue, 12 Jul 2005 17:43:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262502AbVGLVjX (ORCPT ); Tue, 12 Jul 2005 17:39:23 -0400 Received: from e33.co.us.ibm.com ([32.97.110.131]:40677 "EHLO e33.co.us.ibm.com") by vger.kernel.org with ESMTP id S262491AbVGLVim (ORCPT ); Tue, 12 Jul 2005 17:38:42 -0400 From: Tom Zanussi MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <17108.14426.607378.262959@tut.ibm.com> Date: Tue, 12 Jul 2005 16:38:34 -0500 To: Tom Zanussi Cc: Steven Rostedt , Jason Baron , richardj_moore@uk.ibm.com, varap@us.ibm.com, karim@opersys.com, linux-kernel@vger.kernel.org, akpm@osdl.org Subject: Re: Merging relayfs? In-Reply-To: <17107.63309.475838.635711@tut.ibm.com> References: <17107.6290.734560.231978@tut.ibm.com> <1121183607.6917.47.camel@localhost.localdomain> <17107.60140.948145.153144@tut.ibm.com> <1121185393.6917.59.camel@localhost.localdomain> <17107.61864.621401.440354@tut.ibm.com> <1121186981.6917.67.camel@localhost.localdomain> <17107.63309.475838.635711@tut.ibm.com> X-Mailer: VM 7.19 under 21.4 (patch 15) "Security Through Obscurity" XEmacs Lucid Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Tom Zanussi writes: > Steven Rostedt writes: > > On Tue, 2005-07-12 at 11:36 -0500, Tom Zanussi wrote: > > > > > > > > > > I totally agree that the vmalloc way is faster, but I would also argue > > > > that the accounting to handle the separate pages would not even be > > > > noticeable with the time it takes to do the actual copying into the > > > > buffer. So if the accounting adds 3ns on top of 500ns to complete, I > > > > don't think people will mind. > > > > > > OK, it sounds like something to experiment with - I can play around > > > with it, and later submit a patch to remove vmap if it works out. > > > Does that sound like a good idea? > > > > Sounds good to me, since different approaches to a problem are always > > good, since it allows for comparing the plusses and minuses. Not sure > > if you want to take a crack using my ring buffers, but although they are > > quite confusing, they have been fully tested, since I haven't changed > > the ring buffer for a few years (although logdev itself has gone > through > > I was thinking of something simpler, like just using the page array we > already have in relayfs, but not vmap'ing it and instead writing to > the current page, detecting when to split a record, moving on to the > next page, etc. and seeing how it compares with the vmap version. > Just a clarification - I didn't mean to ignore your ring buffers - it would be good to try both, I think... Tom