From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 3 Sep 2001 22:32:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 3 Sep 2001 22:31:55 -0400 Received: from penguin.e-mind.com ([195.223.140.120]:7248 "EHLO penguin.e-mind.com") by vger.kernel.org with ESMTP id ; Mon, 3 Sep 2001 22:31:40 -0400 Date: Tue, 4 Sep 2001 04:31:51 +0200 From: Andrea Arcangeli To: Paul Mackerras Cc: Richard Henderson , David Mosberger , torvalds@transmeta.com, linux-kernel@vger.kernel.org, davem@redhat.com Subject: Re: [PATCH] avoid unnecessary cache flushes Message-ID: <20010904043151.H699@athlon.random> In-Reply-To: <15247.29338.3671.548678@cargo.ozlabs.ibm.com> <20010903131436.A16069@twiddle.net> <15251.59286.154267.431231@napali.hpl.hp.com> <20010903134125.B16069@twiddle.net> <15252.13330.652765.959658@cargo.ozlabs.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <15252.13330.652765.959658@cargo.ozlabs.ibm.com>; from paulus@samba.org on Tue, Sep 04, 2001 at 11:53:22AM +1000 X-GnuPG-Key-URL: http://e-mind.com/~andrea/aa.gnupg.asc X-PGP-Key-URL: http://e-mind.com/~andrea/aa.asc Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 04, 2001 at 11:53:22AM +1000, Paul Mackerras wrote: > For alpha, the thing that my patch does that might hurt is the change > from flush_icache_page to flush_icache_range in kernel/ptrace.c. Any > comment on that? For the alpha such change will imply a performance penablity (will throw away the whole icache, not only the one belonging to the ptraced task). We cannot change flush_icache_range to bump the asn because there's no vma in the flush_icache_range API (flush_icache_range in short is for the kernel side, like with vmalloc and kernel modules where a vma/mm/tsk wouldn't make sense anyways). what's the point of such change? The whole point of the patch is to work with pages not with virtual addresses so you can do the bitflag bookeeping on the page structure, so I don't see why would you want to do the opposite change there. Andrea