From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755186AbZBTSXe (ORCPT ); Fri, 20 Feb 2009 13:23:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751237AbZBTSXW (ORCPT ); Fri, 20 Feb 2009 13:23:22 -0500 Received: from smtp-outbound-2.vmware.com ([65.115.85.73]:56279 "EHLO smtp-outbound-2.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751838AbZBTSXV (ORCPT ); Fri, 20 Feb 2009 13:23:21 -0500 Subject: Re: x86, vmi: TSC going backwards check in vmi clocksource From: Alok Kataria Reply-To: akataria@vmware.com To: Ingo Molnar Cc: the arch/x86 maintainers , LKML , Zach Amsden , Andrew Morton In-Reply-To: <20090220175841.GQ24538@elte.hu> References: <1234989235.7991.2.camel@alok-dev1> <20090220175841.GQ24538@elte.hu> Content-Type: text/plain Organization: VMware INC. Date: Fri, 20 Feb 2009 10:23:18 -0800 Message-Id: <1235154198.1547.3.camel@alok-dev1> Mime-Version: 1.0 X-Mailer: Evolution 2.8.0 (2.8.0-40.el5_1.1) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2009-02-20 at 09:58 -0800, Ingo Molnar wrote: > * Alok Kataria wrote: > > > static cycle_t read_real_cycles(void) > > { > > - return vmi_timer_ops.get_cycle_counter(VMI_CYCLES_REAL); > > + cycle_t ret = (cycle_t)vmi_timer_ops.get_cycle_counter(VMI_CYCLES_REAL); > > + return ret >= clocksource_vmi.cycle_last ? > > + ret : clocksource_vmi.cycle_last; > > btw., could you please clean this up to use max()? Please find it below, on top of current tip/master. -- cleanup vmi_read_cycles to use max() Signed-off-by: Alok N Kataria --- arch/x86/kernel/vmiclock_32.c | 3 +-- 1 files changed, 1 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/vmiclock_32.c b/arch/x86/kernel/vmiclock_32.c index 9cd28c0..b77ad57 100644 --- a/arch/x86/kernel/vmiclock_32.c +++ b/arch/x86/kernel/vmiclock_32.c @@ -288,8 +288,7 @@ static struct clocksource clocksource_vmi; static cycle_t read_real_cycles(void) { cycle_t ret = (cycle_t)vmi_timer_ops.get_cycle_counter(VMI_CYCLES_REAL); - return ret >= clocksource_vmi.cycle_last ? - ret : clocksource_vmi.cycle_last; + return max(ret, clocksource_vmi.cycle_last); } static struct clocksource clocksource_vmi = {