From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266569AbUBEU6d (ORCPT ); Thu, 5 Feb 2004 15:58:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266629AbUBEU6d (ORCPT ); Thu, 5 Feb 2004 15:58:33 -0500 Received: from defout.telus.net ([199.185.220.240]:51628 "EHLO priv-edtnes57.telusplanet.net") by vger.kernel.org with ESMTP id S266569AbUBEU6b (ORCPT ); Thu, 5 Feb 2004 15:58:31 -0500 Subject: Re: [BUG] 2.6.2 crazy mouse under heavy load From: Bob Gill To: Linux Kernel Mailing List Content-Type: text/plain Message-Id: <1076014751.4682.22.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.5 (1.4.5-7) Date: Thu, 05 Feb 2004 13:59:12 -0700 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org The exception seems to be coming from linux-2.6.2/drivers/input/mouse/psmouse-base.c, specifically from if (psmouse->state == PSMOUSE_ACTIVATED && psmouse->pktcnt && time_after(jiffies, psmouse->last + HZ/2)) { printk(KERN_WARNING "psmouse.c: %s at %s lost synchronization, throwing %d bytes away.\n", psmouse->name, psmouse->phys, psmouse->pktcnt); psmouse->pktcnt = 0; } where (for me) HZ is 1804768000, and therefore HZ/2 is 902384000, psmouse->pktcnt is 3, and (I assume) PSMOUSE_ACTIVATED is non-0 after boot. I assume that pktcnt is fed by interrupt, and the problem then is that psmouse->last + HZ/2 blows past the jiffies value, causing the warning message to be issued. When mouse service finally comes back, pktcnt is non-zero (and possibly whatever the maximum is that it will hold), and when it flushes, the mouse pointer goes nuts for a second. The real problem then, is why does the sum of ps->last + HZ/2 grow to beyond the size of jiffies (or what is delaying the mouse service)? This is just a rough guesstimate of what is going on, but seems to fit the facts. Cheers! Bob