Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752579Ab1BIJVv (ORCPT ); Wed, 9 Feb 2011 04:21:51 -0500 Received: from mail-bw0-f46.google.com ([209.85.214.46]:61970 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751317Ab1BIJVt (ORCPT ); Wed, 9 Feb 2011 04:21:49 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:x-enigmail-version:content-type :content-transfer-encoding; b=qQuG8V+c8hb0kA2J6vJ4GkJeZf6ko2+/mV6GPPmgziS14DCrt8HypTpAEF3/s4n1nM XsywEGsZ8XUDWDUxJQgzvDpOvnSLBCcUG1uvF6iolyo4hs3dwTfaoQqfL2uVloVERb3O W/R2Duqkru8vMI3TU9Pmx1sAwdlreGYE2FT0o= Message-ID: <4D525CA8.60604@suse.cz> Date: Wed, 09 Feb 2011 10:21:44 +0100 From: Jiri Slaby User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; cs-CZ; rv:1.9.2.13) Gecko/20101206 SUSE/3.1.7 Thunderbird/3.1.7 MIME-Version: 1.0 To: Jan Beulich CC: akpm@linux-foundation.org, Linus Torvalds , Tim Deegan , Jeremy Fitzhardinge , linux-kernel@vger.kernel.org Subject: Re: [PATCH] fix jiffy calculations in calibrate_delay_direct to handle overflow References: <4D525EF00200007800030F0F@vpn.id2.novell.com> In-Reply-To: <4D525EF00200007800030F0F@vpn.id2.novell.com> X-Enigmail-Version: 1.1.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1729 Lines: 53 On 02/09/2011 09:31 AM, Jan Beulich wrote: > Fixes a hang when booting as dom0 under Xen, when jiffies can be > quite large by the time the kernel init gets this far. As I wrote this might happen if the boot till this point takes ~ 5 minutes because we start at -5 minutes. That said, is this a candidate for stable? (If so, please CC stable.) > Signed-off-by: Tim Deegan > > !time_after() -> time_before_eq() as per suggestion from Jiri Slaby. > > Signed-off-by: Jan Beulich > Cc: Jiri Slaby > Cc: Jeremy Fitzhardinge > > --- > init/calibrate.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > --- 2.6.38-rc4/init/calibrate.c > +++ 2.6.38-rc4-calibrate-jiffy-overflow/init/calibrate.c > @@ -66,7 +66,7 @@ static unsigned long __cpuinit calibrate > pre_start = 0; > read_current_timer(&start); > start_jiffies = jiffies; > - while (jiffies <= (start_jiffies + 1)) { > + while (time_before_eq(jiffies, start_jiffies + 1)) { > pre_start = start; > read_current_timer(&start); > } > @@ -74,8 +74,8 @@ static unsigned long __cpuinit calibrate > > pre_end = 0; > end = post_start; > - while (jiffies <= > - (start_jiffies + 1 + DELAY_CALIBRATION_TICKS)) { > + while (time_before_eq(jiffies, start_jiffies + 1 + > + DELAY_CALIBRATION_TICKS)) { > pre_end = end; > read_current_timer(&end); > } thanks, -- js suse labs -- 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/