From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754696Ab1IFTYC (ORCPT ); Tue, 6 Sep 2011 15:24:02 -0400 Received: from www.linutronix.de ([62.245.132.108]:51769 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754378Ab1IFTX4 (ORCPT ); Tue, 6 Sep 2011 15:23:56 -0400 Date: Tue, 6 Sep 2011 21:23:55 +0200 (CEST) From: Thomas Gleixner To: Andi Kleen cc: linux-kernel@vger.kernel.org, Andi Kleen Subject: Re: [PATCH 1/3] clockevents: Use an atomic RCU notifier for clockevents In-Reply-To: <1314652136-11350-1-git-send-email-andi@firstfloor.org> Message-ID: References: <1314652136-11350-1-git-send-email-andi@firstfloor.org> 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 Mon, 29 Aug 2011, Andi Kleen wrote: > From: Andi Kleen > > Use an atomic_notifier instead of a raw_notifier for the clockevents > notification. > > This avoids a global lock in the idle path, is a scalability > problem. With this patch we don't have a global lock anymore > at least on systems with an always running timer. And why is that code called on a system with an always running local apic timer at all? The broadcast horror is explicitely only for those systems with wreckaged hardware. Either the patch makes no sense or the changelog or both. Thanks, tglx