From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from hera.kernel.org (hera.kernel.org [140.211.167.34]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id CDC86686B7 for ; Tue, 8 Nov 2005 02:28:13 +1100 (EST) Date: Mon, 7 Nov 2005 08:27:19 -0200 From: Marcelo Tosatti To: Dan Malek Message-ID: <20051107102719.GB15522@logos.cnet> References: <200510302203.25390.pantelis.antoniou@gmail.com> <20051107084431.GA15180@logos.cnet> <6564e160d322329703e5ab866d98618b@embeddedalley.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <6564e160d322329703e5ab866d98618b@embeddedalley.com> Cc: linuxppc-embedded@ozlabs.org Subject: Re: [PATCH 2.6.14] mm: 8xx MM fix for List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Nov 07, 2005 at 09:35:59AM -0500, Dan Malek wrote: > > On Nov 7, 2005, at 3:44 AM, Marcelo Tosatti wrote: > > >Dan, I wonder why we just don't go back to v2.4 behaviour. It is not > >very > >clear to me that "two exception" speedup offsets the additional code > >required > >for "one exception" version. Have you actually done any measurements? > > No, and I didn't actually make these changes, either :-) Ahh, ok. sorry. I remember you arguing that it was faster this way (less code). > I'm working on some 8xx debugging right now, so let's experiment > with some changes. I don't understand why other processors, especially > G2 cores like 82xx, aren't finding the same problems we are having > with 8xx. Logically, we are all doing the same thing, unless there are > some tlb invalidates on these other processors that I'm forgetting > about. I really dont know how the 82xx TLB works, so... > We just seem to be running into stale entries, and we have to fix it. Right - the issue Joakim noted would be one reason for the "two exception" approach.