From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760719AbYDYIbP (ORCPT ); Fri, 25 Apr 2008 04:31:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750766AbYDYIbB (ORCPT ); Fri, 25 Apr 2008 04:31:01 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:54043 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752152AbYDYIa7 (ORCPT ); Fri, 25 Apr 2008 04:30:59 -0400 Date: Fri, 25 Apr 2008 01:30:59 -0700 (PDT) Message-Id: <20080425.013059.252814513.davem@davemloft.net> To: a.p.zijlstra@chello.nl Cc: mingo@elte.hu, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, viro@zeniv.linux.org.uk, alan@lxorguk.ukuu.org.uk, tglx@linutronix.de Subject: Re: [git pull] scheduler/misc fixes From: David Miller In-Reply-To: <1209111858.7115.405.camel@twins> References: <1209109710.7115.400.camel@twins> <20080425.005738.114887644.davem@davemloft.net> <1209111858.7115.405.camel@twins> 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: Peter Zijlstra Date: Fri, 25 Apr 2008 10:24:18 +0200 > FWIW I do think this is a valid 'bug' fix in that the called user func() > can now see its from interrupt context. in_interrupt() would have > reported false due to the missing irq_enter()/irq_exit() - not sure if > any smp_call_function() relies on it though. Understood. I thought a bit and I remember that I did notice long ago that x86 did these irq_enter() calls in SMP call function processing, but it seemed like pure overhead at the time and wasn't actually needed. Anyways, Peter can you give your state machine thing another shot? Maybe it will help us see what is wrong either in the sparc64 code or in the NOHZ/sched bits.