From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.ebshome.net (gate.ebshome.net [208.106.21.240]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "gate.ebshome.net", Issuer "gate.ebshome.net" (not verified)) by ozlabs.org (Postfix) with ESMTP id 91912DE03D for ; Sat, 12 Jan 2008 04:48:25 +1100 (EST) Date: Fri, 11 Jan 2008 09:48:22 -0800 From: Eugene Surovegin To: Stefan Roese Subject: Re: [PATCH] ibm_newemac: Increase number of default rx-/tx-buffers Message-ID: <20080111174822.GB17240@gate.ebshome.net> References: <1199526609-12290-1-git-send-email-sr@denx.de> <1199528388.7291.55.camel@pasglop> <200801051338.17957.sr@denx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <200801051338.17957.sr@denx.de> Cc: linuxppc-dev@ozlabs.org, netdev@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Sat, Jan 05, 2008 at 01:38:17PM +0100, Stefan Roese wrote: > On Saturday 05 January 2008, Benjamin Herrenschmidt wrote: > > On Sat, 2008-01-05 at 10:50 +0100, Stefan Roese wrote: > > > Performance tests done by AMCC have shown that 256 buffer increase the > > > performance of the Linux EMAC driver. So let's update the default > > > values to match this setup. > > > > > > Signed-off-by: Stefan Roese > > > --- > > > > Do we have the numbers ? Did they also measure latency ? > > I hoped this question would not come. ;) No, unfortunately I don't have any > numbers. Just the recommendation from AMCC to always use 256 buffers. This cannot be true for all chips. Default numbers I selected weren't random. In particular, 256 for Tx doesn't make a lot of sense for 405. You just gonna waste memory. I'd be quite reluctant to follow such advices from AMCC without actual details. -- Eugene