From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932343AbVL0OzA (ORCPT ); Tue, 27 Dec 2005 09:55:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932344AbVL0OzA (ORCPT ); Tue, 27 Dec 2005 09:55:00 -0500 Received: from a34-mta02.direcpc.com ([66.82.4.91]:61802 "EHLO a34-mta02.direcway.com") by vger.kernel.org with ESMTP id S932343AbVL0Oy7 (ORCPT ); Tue, 27 Dec 2005 09:54:59 -0500 Date: Tue, 27 Dec 2005 09:54:45 -0500 From: Ben Collins Subject: Re: something about jiffies wraparound overflow In-reply-to: <7cd5d4b40512262046w6f7a8161jfaf1e618e5722b4@mail.gmail.com> To: jeff shia Cc: linux-kernel@vger.kernel.org Message-id: <1135695285.31669.2.camel@localhost.localdomain> Organization: Ubuntu Linux MIME-version: 1.0 X-Mailer: Evolution 2.5.3 Content-type: text/plain Content-transfer-encoding: 7BIT References: <7cd5d4b40512262046w6f7a8161jfaf1e618e5722b4@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2005-12-27 at 12:46 +0800, jeff shia wrote: > 1.why the macros of time_after can solve the jiffies wraparound problem? Basically it assumes that the two values you are comparing will never be more than MAX_ULONG/2 apart. Which for jiffies means 270 some odd days on 32-bit platforms. -- Ben Collins Developer Ubuntu Linux