From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751904Ab2KQOuA (ORCPT ); Sat, 17 Nov 2012 09:50:00 -0500 Received: from mail.skyhub.de ([78.46.96.112]:53610 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751766Ab2KQOt6 (ORCPT ); Sat, 17 Nov 2012 09:49:58 -0500 Date: Sat, 17 Nov 2012 15:50:15 +0100 From: Borislav Petkov To: Linus Torvalds Cc: Rik van Riel , Alan Cox , Ingo Molnar , Andi Kleen , Michel Lespinasse , Peter Zijlstra , Andrea Arcangeli , Mel Gorman , Johannes Weiner , Thomas Gleixner , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, florian@openwrt.org, Borislav Petkov Subject: Re: [PATCH 2/3] x86,mm: drop TLB flush from ptep_set_access_flags Message-ID: <20121117145015.GF16441@x1.osrc.amd.com> Mail-Followup-To: Borislav Petkov , Linus Torvalds , Rik van Riel , Alan Cox , Ingo Molnar , Andi Kleen , Michel Lespinasse , Peter Zijlstra , Andrea Arcangeli , Mel Gorman , Johannes Weiner , Thomas Gleixner , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, florian@openwrt.org, Borislav Petkov References: <508A8D31.9000106@redhat.com> <20121026132601.GC9886@gmail.com> <20121026144502.6e94643e@dull> <20121026221254.7d32c8bf@pyramind.ukuu.org.uk> <508BE459.2080406@redhat.com> <20121029165705.GA4693@x1.osrc.amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 29, 2012 at 10:06:15AM -0700, Linus Torvalds wrote: > On Mon, Oct 29, 2012 at 9:57 AM, Borislav Petkov wrote: > > > > On current AMD64 processors, > > Can you verify that this is true for older cpu's too (ie the old > pre-64-bit ones, say K6 and original Athlon)? Albeit with a slight delay, the answer is yes: all AMD cpus automatically invalidate cached TLB entries (and intermediate walk results, for that matter) on a #PF. I don't know, however, whether it would be prudent to have some sort of a cheap assertion in the code (cheaper than INVLPG %ADDR, although on older cpus we do MOV CR3) just in case. This should be enabled only with DEBUG_VM on, of course... HTH. -- Regards/Gruss, Boris. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx139.postini.com [74.125.245.139]) by kanga.kvack.org (Postfix) with SMTP id CE6356B004D for ; Sat, 17 Nov 2012 09:49:57 -0500 (EST) Date: Sat, 17 Nov 2012 15:50:15 +0100 From: Borislav Petkov Subject: Re: [PATCH 2/3] x86,mm: drop TLB flush from ptep_set_access_flags Message-ID: <20121117145015.GF16441@x1.osrc.amd.com> References: <508A8D31.9000106@redhat.com> <20121026132601.GC9886@gmail.com> <20121026144502.6e94643e@dull> <20121026221254.7d32c8bf@pyramind.ukuu.org.uk> <508BE459.2080406@redhat.com> <20121029165705.GA4693@x1.osrc.amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Linus Torvalds Cc: Rik van Riel , Alan Cox , Ingo Molnar , Andi Kleen , Michel Lespinasse , Peter Zijlstra , Andrea Arcangeli , Mel Gorman , Johannes Weiner , Thomas Gleixner , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, florian@openwrt.org, Borislav Petkov On Mon, Oct 29, 2012 at 10:06:15AM -0700, Linus Torvalds wrote: > On Mon, Oct 29, 2012 at 9:57 AM, Borislav Petkov wrote: > > > > On current AMD64 processors, > > Can you verify that this is true for older cpu's too (ie the old > pre-64-bit ones, say K6 and original Athlon)? Albeit with a slight delay, the answer is yes: all AMD cpus automatically invalidate cached TLB entries (and intermediate walk results, for that matter) on a #PF. I don't know, however, whether it would be prudent to have some sort of a cheap assertion in the code (cheaper than INVLPG %ADDR, although on older cpus we do MOV CR3) just in case. This should be enabled only with DEBUG_VM on, of course... HTH. -- Regards/Gruss, Boris. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org