Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752841Ab2BXFmJ (ORCPT ); Fri, 24 Feb 2012 00:42:09 -0500 Received: from mail-wi0-f174.google.com ([209.85.212.174]:49382 "EHLO mail-wi0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751117Ab2BXFmG (ORCPT ); Fri, 24 Feb 2012 00:42:06 -0500 Authentication-Results: mr.google.com; spf=pass (google.com: domain of yong.zhang0@gmail.com designates 10.180.95.1 as permitted sender) smtp.mail=yong.zhang0@gmail.com; dkim=pass header.i=yong.zhang0@gmail.com Date: Fri, 24 Feb 2012 13:41:50 +0800 From: Yong Zhang To: Venki Pallipadi Cc: Peter Zijlstra , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Suresh Siddha , Aaron Durbin , Paul Turner , linux-kernel@vger.kernel.org Subject: Re: [PATCH] Extend mwait idle to optimize away CAL and RES interrupts to an idle CPU -v1 Message-ID: <20120224054150.GA17543@zhy> Reply-To: Yong Zhang References: <1329957415-15239-1-git-send-email-venki@google.com> <1329989454.24994.57.camel@twins> 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 Content-Length: 717 Lines: 18 On Thu, Feb 23, 2012 at 11:34:11AM -0800, Venki Pallipadi wrote: > On Thu, Feb 23, 2012 at 1:30 AM, Peter Zijlstra wrote: > > Why not scheduler_ipi()? > > Was trying to avoid irq_enter/exit. As the work here is done in idle > thread context, I though we could avoid enter/exit. It seems we could not. At least RCU need it, see commit c5d753a55, otherwise we will get warning like 'RCU used illegally from extended quiescent state!' Thanks, Yong -- 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/