Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264094AbTEGP7n (ORCPT ); Wed, 7 May 2003 11:59:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264095AbTEGP7n (ORCPT ); Wed, 7 May 2003 11:59:43 -0400 Received: from h-68-165-86-241.DLLATX37.covad.net ([68.165.86.241]:49457 "EHLO sol.microgate.com") by vger.kernel.org with ESMTP id S264094AbTEGP7k (ORCPT ); Wed, 7 May 2003 11:59:40 -0400 Subject: 2.5.69 Interrupt Latency From: Paul Fulghum To: "linux-kernel@vger.kernel.org" Content-Type: text/plain Organization: Message-Id: <1052323940.2360.7.camel@diemos> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.2.2 (1.2.2-4) Date: 07 May 2003 11:12:20 -0500 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1057 Lines: 32 Starting with kernel version 2.5.69, I am encountering what appears to be increased interrupt latency or spikes in interrupt latency. I noticed this on two serial drivers that use programmed I/O with FIFOs. On 2.5.68, no problems. On 2.5.69 plenty of underruns. Inspecting the driver tracing, it does not look like lost interrupts. I see this on 2 different machines (one SMP server and one laptop). There were changes involving the return type of interrupt handlers (from void to irqreturn_t) in 2.5.69. Could this be related? Has anyone else seen similar results? If I can get time, I'll try and hook up a scope to measure the latencies precisely. I want to check to see if this is a known problems before doing so. -- Paul Fulghum, paulkf@microgate.com Microgate Corporation, http://www.microgate.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/