From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751813Ab0JLWMd (ORCPT ); Tue, 12 Oct 2010 18:12:33 -0400 Received: from mga09.intel.com ([134.134.136.24]:32396 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751641Ab0JLWMc (ORCPT ); Tue, 12 Oct 2010 18:12:32 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.57,322,1283756400"; d="scan'208";a="563320420" Date: Tue, 12 Oct 2010 15:12:30 -0700 From: Jacob Pan To: Thomas Gleixner Cc: linux-kernel@vger.kernel.org, mingo@redhat.com, hpa@zytor.com, mingo@elte.hu, linux-tip-commits@vger.kernel.org Subject: Re: [tip:irq/core] x86: Sanitize apb timer interrupt handling Message-ID: <20101012151230.00000402@unknown> In-Reply-To: References: <20101012142000.00001358@unknown> Organization: Intel OTC X-Mailer: Claws Mail 3.7.4cvs1 (GTK+ 2.16.0; i586-pc-mingw32msvc) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thomas Gleixner Tue, 12 Oct 2010 23:28:19 +0200 (CEST) >On Tue, 12 Oct 2010, Jacob Pan wrote: > >> >> >x86: Sanitize apb timer interrupt handling >> > >> >Disable the interrupt in CPU_DEAD where it belongs. >> My main concern is the performance cost. The power management code for >> Moorestown system make use of the cpu hotplug code (disable_nonboot_cpus) >> but much more frequently. The system low power states are call S0 idle >> state (s0ix). >> >> Leaving the irq enabled at the chip and desc level between S0ix states >> might give some performance benefit. That was my original thought. >> Will it cause problems? > >Errm. I merily moved it to the place where it should be. You do the >disable/enable dance already today. > I think I only do disable/enable at the timer HW level today during cpu hp notification, not calling disable_irq(). Am i missing something? Thanks, Jacob