From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756676Ab0JUSQ5 (ORCPT ); Thu, 21 Oct 2010 14:16:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46239 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753982Ab0JUSQ4 (ORCPT ); Thu, 21 Oct 2010 14:16:56 -0400 Date: Thu, 21 Oct 2010 20:12:20 +0200 From: Oleg Nesterov To: Brian Behlendorf Cc: LKML , Andrew Morton Subject: Re: [PATCH] Make div64_u64() precise on 32bit platforms Message-ID: <20101021181220.GA8827@redhat.com> References: <201010121227.05735.behlendorf1@llnl.gov> <20101013213746.GA27248@redhat.com> <20101014121159.GA407@redhat.com> <1287683202.16680.44.camel@pip> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1287683202.16680.44.camel@pip> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andrew, please drop lib-div64c-document-that-div64_u64-is-not-precise-on-32bit-platforms.patch On 10/21, Brian Behlendorf wrote: > > I think we should use your simpler version. There's no good reason to > make this more complicated than it needs to be. I haven't been able to > find a test case where your changes get the wrong result. Great! > From: Brian Behlendorf > Date: Thu, 5 Aug 2010 14:59:11 -0700 > Subject: [PATCH] Fix div64_u64 for 32bit platforms > > The current implementation of div64_u64 for 32bit systems returns > an approximately correct result when the divisor exceeds 32bits. > Since doing 64bit division using 32bit hardware is a long since > solved problem we just use one of the existing proven methods. Brian, you forgot to add your sob. Hopefully Andrew can add Signed-off-by: Brian Behlendorf Signed-off-by: Oleg Nesterov