From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262559AbVHDPVb (ORCPT ); Thu, 4 Aug 2005 11:21:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262581AbVHDPTU (ORCPT ); Thu, 4 Aug 2005 11:19:20 -0400 Received: from mx1.elte.hu ([157.181.1.137]:42444 "EHLO mx1.elte.hu") by vger.kernel.org with ESMTP id S262577AbVHDPTH (ORCPT ); Thu, 4 Aug 2005 11:19:07 -0400 Date: Thu, 4 Aug 2005 17:19:11 +0200 From: Ingo Molnar To: Karsten Wiese Cc: linux-kernel@vger.kernel.org, discuss@x86-64.org, ak@suse.de Subject: Re: [RFC] AMD64 @ K8T800/VT8237: Doubled IOAPIC-level-interrupt rate Message-ID: <20050804151911.GA20765@elte.hu> References: <200508041625.41296.annabellesgarden@yahoo.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200508041625.41296.annabellesgarden@yahoo.de> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamVersion: MailScanner 4.31.6-itk1 (ELTE 1.2) SpamAssassin 2.63 ClamAV 0.73 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Karsten Wiese wrote: > Hi, > > this should likely be addressed to VIA Taiwan, > but I don't know their engineer's e-mail address and their forum > doesn't work for me. > Maybe somebody here has a clue? > Or maybe this is even motherboard specific? > > To reproduce: > $ aplay -Dhw:0 -fdat /dev/zero > > On a sane system (or here in PIC Mode) you'll see > around 12 Interrupts/s. > Here I see 24. i think this is an effect of the 'POST-flush' symptom: the IO-APIC write of unmasking the IRQ does not reach the chipset before the ACK via the local-APIC does. Does it work fine if you artificially read after the IO-APIC write? Ingo