From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755341Ab1IFXTQ (ORCPT ); Tue, 6 Sep 2011 19:19:16 -0400 Received: from www.linutronix.de ([62.245.132.108]:58667 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754830Ab1IFXTI (ORCPT ); Tue, 6 Sep 2011 19:19:08 -0400 Date: Wed, 7 Sep 2011 01:19:06 +0200 (CEST) From: Thomas Gleixner To: Andi Kleen cc: Andi Kleen , linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] clockevents: Use an atomic RCU notifier for clockevents In-Reply-To: <20110906224228.GA5534@alboin.fm.intel.com> Message-ID: References: <1314652136-11350-1-git-send-email-andi@firstfloor.org> <20110906203338.GL7761@one.firstfloor.org> <20110906224228.GA5534@alboin.fm.intel.com> User-Agent: Alpine 2.02 (LFD 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 6 Sep 2011, Andi Kleen wrote: > > The idle code, at least the one in drivers/idle/intel_idle.c, does > > _NOT_ call into that code at all when a reliable lapic timer is > > available: > > But the ACPI idle doesn't check that, so it still has a scalability problem. > > Hmm ok so could add that check into acpi idle too I guess, but then ACPI > idle doesn't normally know anything about CPUs. > > > Either you are using different code or your machine does not have that > > ARAT flag set. > > The second test was using ACPI idle. And as I said in that very same mail: > > Same applies for drivers/acpi/processor_idle.c lapic_timer_check_state() { if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT)) return; .... WTF are you talking about? Thanks, tglx