From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261463AbVGLO2p (ORCPT ); Tue, 12 Jul 2005 10:28:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261462AbVGLO0n (ORCPT ); Tue, 12 Jul 2005 10:26:43 -0400 Received: from gateway-1237.mvista.com ([12.44.186.158]:32758 "EHLO av.mvista.com") by vger.kernel.org with ESMTP id S261463AbVGLOZo (ORCPT ); Tue, 12 Jul 2005 10:25:44 -0400 Subject: Re: Real-Time Preemption, -RT-2.6.12-final-V0.7.50-24 From: Daniel Walker To: Ingo Molnar Cc: Karsten Wiese , linux-kernel@vger.kernel.org In-Reply-To: <20050712140251.GB18296@elte.hu> References: <200507121223.10704.annabellesgarden@yahoo.de> <20050712140251.GB18296@elte.hu> Content-Type: text/plain Date: Tue, 12 Jul 2005 07:25:38 -0700 Message-Id: <1121178339.10199.8.camel@c-67-188-6-232.hsd1.ca.comcast.net> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 (2.0.4-4) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2005-07-12 at 16:02 +0200, Ingo Molnar wrote: > * Karsten Wiese wrote: > > > Hi Ingo > > > > I've refined io_apic.c a little more: > > great. I've applied these changes and have released the -28 patch. (note > that the last chunk of your patch was malformed, have applied it by > hand.) > > i'm wondering what your thoughts are about IOAPIC_POSTFLUSH - i had to > turn it on unconditionally again, to get rid of spurious interrupts and > outright interrupt storms (and resulting lockups) on some systems. > IOAPIC_POSTFLUSH is now causing much of the IO-APIC related IRQ handling > overhead. I observed a situation on a dual xeon where IOAPIC_POSTFLUSH , if on, would actually cause spurious interrupts. It was odd cause it's suppose to stop them .. If there was a lot of interrupt traffic on one IRQ , it would cause interrupt traffic on another IRQ. This would result in "nobody cared" messages , and the storming IRQ line would get shutdown. This would only happen in PREEMPT_RT . Daniel