From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030338AbWD1JYl (ORCPT ); Fri, 28 Apr 2006 05:24:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030337AbWD1JYl (ORCPT ); Fri, 28 Apr 2006 05:24:41 -0400 Received: from mtagate2.de.ibm.com ([195.212.29.151]:4100 "EHLO mtagate2.de.ibm.com") by vger.kernel.org with ESMTP id S1030335AbWD1JYk (ORCPT ); Fri, 28 Apr 2006 05:24:40 -0400 Subject: Re: [patch 11/13] s390: instruction processing damage handling. From: Martin Schwidefsky Reply-To: schwidefsky@de.ibm.com To: Heiko Carstens Cc: Josef Sipek , linux-kernel@vger.kernel.org, akpm@osdl.org In-Reply-To: <20060428083903.GA11819@osiris.boeblingen.de.ibm.com> References: <20060424150544.GL15613@skybase> <20060428073358.GA15166@filer.fsl.cs.sunysb.edu> <20060428083903.GA11819@osiris.boeblingen.de.ibm.com> Content-Type: text/plain Organization: IBM Corporation Date: Fri, 28 Apr 2006 11:24:44 +0200 Message-Id: <1146216285.5138.1.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.4.2.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2006-04-28 at 10:39 +0200, Heiko Carstens wrote: > > > +++ linux-2.6-patched/drivers/s390/s390mach.c 2006-04-24 16:47:28.000000000 +0200 > > ... > > > +#define MAX_IPD_TIME (5 * 60 * 100 * 1000) /* 5 minutes */ > > > > I'm no s390 expert, but shouldn't the above use something like HZ? > > Using HZ here feels just wrong to me. MAX_IPD_TIME has nothing to do with the > timer frequency. In this case it's used to tell if there were 30 machine > checks within the last 5 minutes (in a usec granularity). It's just by > accident that this could be expressed using HZ. > (5 * 60 * USEC_PER_SEC) would probably look better... Using HZ would be wrong. The check that uses MAX_IPD_TIME compares it against the result of a get_clock() call. That uses the TOD Clock directly, there is no dependency on HZ. -- blue skies, Martin. Martin Schwidefsky Linux for zSeries Development & Services IBM Deutschland Entwicklung GmbH "Reality continues to ruin my life." - Calvin.