From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: 3c59x (was Route cache performance under stress) Date: Tue, 10 Jun 2003 12:23:42 -0400 Sender: netdev-bounce@oss.sgi.com Message-ID: <20030610162342.GB1959@gtf.org> References: <20030610.085342.41654796.davem@redhat.com> <20030610162029.GA8168@wotan.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Bogdan Costescu , "David S. Miller" , hadi@shell.cyberus.ca, ralph+d@istop.com, xerox@foonet.net, sim@netnation.com, fw@deneb.enyo.de, netdev@oss.sgi.com, linux-net@vger.kernel.org Return-path: To: Andi Kleen Content-Disposition: inline In-Reply-To: <20030610162029.GA8168@wotan.suse.de> Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org On Tue, Jun 10, 2003 at 06:20:29PM +0200, Andi Kleen wrote: > Can't you just wrap it in a few macros and offer a config for those > who want the best performance and a runtime test for the others? > Then switch between PIO and mmio dynamically. > > Even runtime test should be pretty painless these days, the CPU normally > can execute hundreds or even thousands of tests in the time it takes to > wait for an mmio or even PIO. I prefer a compile-time test. But yes, this is what several other net drivers do: offer a config option for MMIO (or PIO), and the default is MMIO unless that is known to be unsafe on certain boards (which, unfortunately, it is). Jeff