From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756756AbYECXkg (ORCPT ); Sat, 3 May 2008 19:40:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754990AbYECXk3 (ORCPT ); Sat, 3 May 2008 19:40:29 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:46971 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754988AbYECXk2 (ORCPT ); Sat, 3 May 2008 19:40:28 -0400 Date: Sat, 03 May 2008 16:40:24 -0700 (PDT) Message-Id: <20080503.164024.265682957.davem@davemloft.net> To: mingo@elte.hu Cc: benh@kernel.crashing.org, a.p.zijlstra@chello.nl, efault@gmx.de, elendil@planet.nl, parag.warudkar@gmail.com, linux-kernel@vger.kernel.org, guichaz@yahoo.fr, andi@firstfloor.org Subject: Re: 'global' rq->clock From: David Miller In-Reply-To: <20080503233825.GB30600@elte.hu> References: <20080503.160408.238581868.davem@davemloft.net> <20080503.163600.93588714.davem@davemloft.net> <20080503233825.GB30600@elte.hu> X-Mailer: Mew version 5.2 on Emacs 22.1 / Mule 5.0 (SAKAKI) 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 From: Ingo Molnar Date: Sun, 4 May 2008 01:38:25 +0200 > ah, good! It really looks like unnecessary overhead for the "simple > IPIs". But ... i'm wondering ... what about softirq processing? Do these > IPIs process softirqs on the way out? In that case the non-processed > jiffies might be a problem. > > it's all a bit messy. I wish we could start turning jiffies into a > function (which would just read GTOD and estimate jiffies from there), > but i fear we are not there yet ... I think Peter Z. made a good point that we probably need to keep it there for smp_call_function() receivers, so that the called functions can test the context they are in accurately.