Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760517AbYJISke (ORCPT ); Thu, 9 Oct 2008 14:40:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754742AbYJISkY (ORCPT ); Thu, 9 Oct 2008 14:40:24 -0400 Received: from mx2.redhat.com ([66.187.237.31]:37904 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754721AbYJISkX (ORCPT ); Thu, 9 Oct 2008 14:40:23 -0400 Message-ID: <48EE4FC4.7070902@redhat.com> Date: Thu, 09 Oct 2008 14:39:00 -0400 From: Chris Snook User-Agent: Thunderbird 2.0.0.17 (Macintosh/20080914) MIME-Version: 1.0 To: Thomas Gleixner CC: Jeff Hansen , torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, mingo@elte.hu Subject: Re: [PATCH] Re: x86_32 tsc/pit and hrtimers References: <48ECFEDC.90305@redhat.com> <48ED1728.5060708@redhat.com> <48ED2A89.3000902@redhat.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1214 Lines: 32 Thomas Gleixner wrote: > On Wed, 8 Oct 2008, Jeff Hansen wrote: > >> [HRTIMER]: Add highres=noverify option to bypass clocksource verification >> >> This disregards the CLOCK_SOURCE_MUST_VERIFY flag on all clocksources. >> This is particularly useful on legacy x86_32 systems that have no ACPI, >> LAPIC, or HPET timers, where only TSC and PIT are available. > > While I agree in principle, adding this to highres is the wrong thing > to do. This is a property of clocksources and not of high resolution > timer support. > > The affected clocksource is TSC and it should go there as a command > line option e.g. tsc=stable, which in turn clears the > CLOCK_SOURCE_MUST_VERIFY flag in the tsc clocksource. > > Thanks, > > tglx Fair enough, but do you think it's worthwhile to have an option to disable CLOCK_SOURCE_MUST_VERIFY checking for all timers, or should we implement this on a case-by-case basis when there's legitimate cause, like with TSC? -- Chris -- 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/