From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Liu Subject: Re: [Xen-devel] [PATCH net] xen-netback: add the scenario which now beyond the range time_after_eq(). Date: Thu, 17 Oct 2013 15:06:11 +0100 Message-ID: <20131017140611.GM16371@zion.uk.xensource.com> References: <1381944167-24918-1-git-send-email-jianhai.luan@oracle.com> <525FBB4F02000078000FBB30@nat28.tlf.novell.com> <525FA79F.8060601@oracle.com> <525FAABE.5080806@citrix.com> <525FB9BC.9010608@oracle.com> <525FBC7F.9040800@citrix.com> <525FED42.4040608@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: David Vrabel , Jan Beulich , , , , , To: jianhai luan Return-path: Received: from smtp02.citrix.com ([66.165.176.63]:65366 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755902Ab3JQOGM (ORCPT ); Thu, 17 Oct 2013 10:06:12 -0400 Content-Disposition: inline In-Reply-To: <525FED42.4040608@oracle.com> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Oct 17, 2013 at 09:59:30PM +0800, jianhai luan wrote: [...] > >>>>If use time_after_eq64(), expire ,next_credit and other member will must > >>>>be u64. > >>>Yes, you'll need to store next_credit as a u64 in vif instead of > >>>calculating it in tx_credit_exceeded from expires (which is only an > >>>unsigned long). > >>I know that. Even we use u64, time_after_eq() will also do wrong judge > >>in theory (not in reality because need long long time). > >If jiffies_64 has millisecond resolution that would be more than > >500,000,000 years. > > Yes, I agree the fact. > > > >>I think the two better fixed way is below: > >> - By time_before() to judge if now beyond MAX_ULONG/2 > >This is broken, so no. > > Where is broken? would you like to help me point it out. I think David means you didn't actually fix the problem. Your solution is merely a workaround. > > > >David