From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031551Ab2CWAua (ORCPT ); Thu, 22 Mar 2012 20:50:30 -0400 Received: from mga14.intel.com ([143.182.124.37]:45710 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756413Ab2CWAu3 (ORCPT ); Thu, 22 Mar 2012 20:50:29 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="80647252" Subject: Re: [patch] x86, tlb: switch cr3 in leave_mm() only when needed From: Suresh Siddha Reply-To: Suresh Siddha To: Linus Torvalds Cc: "H. Peter Anvin" , Ingo Molnar , Len Brown , LKML Date: Thu, 22 Mar 2012 17:51:39 -0700 In-Reply-To: References: <1332459220.16101.144.camel@sbsiddha-desk.sc.intel.com> <1332460885.16101.147.camel@sbsiddha-desk.sc.intel.com> <4F6BC1C4.6050502@zytor.com> Organization: Intel Corp Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.0.3 (3.0.3-1.fc15) Content-Transfer-Encoding: 7bit Message-ID: <1332463899.16101.158.camel@sbsiddha-desk.sc.intel.com> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2012-03-22 at 17:37 -0700, Linus Torvalds wrote: > On Thu, Mar 22, 2012 at 5:20 PM, H. Peter Anvin wrote: > > > > Looks great to me. Linus, do you want this one later in the window if > > it tests out OK between now and then, or is it too late? > > It's small and trivial, so it's fine. I *would* like to hear whether > it actually makes any real difference, though. I do see "intel_idle()" > as a big cost in idle profiles, and I assume that translates to power > use too, but if you guys have some actual numbers, that would be even > better. I was reviewing this code in some other context and thought this optimization makes sense. Unless someone beats me, I can collect some data on Monday. thanks, suresh