Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756260AbYBILQc (ORCPT ); Sat, 9 Feb 2008 06:16:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752195AbYBILQZ (ORCPT ); Sat, 9 Feb 2008 06:16:25 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:40527 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752193AbYBILQY (ORCPT ); Sat, 9 Feb 2008 06:16:24 -0500 Date: Sat, 9 Feb 2008 12:16:12 +0100 From: Ingo Molnar To: Andi Kleen Cc: tglx@linutronix.de, linux-kernel@vger.kernel.org, "H. Peter Anvin" Subject: Re: [PATCH] [1/2] Use standard global TLB flushes in MTRR code v2 Message-ID: <20080209111612.GA5273@elte.hu> References: <20080208122.996401758@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080208122.996401758@suse.de> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 963 Lines: 24 * Andi Kleen wrote: > This is more idiomatic and it does not really make sense for this code > to implement a own TLB flushing variant. > > The control registers will be read/written a few times more, but that > should not really matter for this code. what you do not point out in the changelog, and what i've mentioned to you in past replies but you still ignore it: that the patch changes what the code does - we now keep PGE enabled in cr4 during the MTRR changing. the MTRR code is historically fragile, rarely triggered code, laced with CPU errata. The change brings us absolutely nothing (it in fact increases the code size a bit) and it is just not worth the risk at this stage. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/