From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752016AbbKZMLW (ORCPT ); Thu, 26 Nov 2015 07:11:22 -0500 Received: from szxga01-in.huawei.com ([58.251.152.64]:56292 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751565AbbKZMLT (ORCPT ); Thu, 26 Nov 2015 07:11:19 -0500 Subject: Re: [PATCH] cpuset: Replace all instances of time_t with time64_t To: Tejun Heo , Arnd Bergmann References: <2798266.9VZu01a7d1@wuerfel> <20151125190150.GA14240@htj.duckdns.org> CC: , Heena Sirwani , , , , John Stultz From: Zefan Li Message-ID: <5656F64A.609@huawei.com> Date: Thu, 26 Nov 2015 20:08:42 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: <20151125190150.GA14240@htj.duckdns.org> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.19.236] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020201.5656F6DF.0040,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 68006a29289d0a2c8a72135cc9b89868 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2015/11/26 3:01, Tejun Heo wrote: > On Wed, Nov 25, 2015 at 04:16:55PM +0100, Arnd Bergmann wrote: >> The following patch replaces all instances of time_t with time64_t i.e. >> change the type used for representing time from 32-bit to 64-bit. All >> 32-bit kernels to date use a signed 32-bit time_t type, which can only >> represent time until January 2038. Since embedded systems running 32-bit >> Linux are going to survive beyond that date, we have to change all >> current uses, in a backwards compatible way. >> >> The patch also changes the function get_seconds() that returns a 32-bit >> integer to ktime_get_seconds() that returns seconds as 64-bit integer. >> >> The patch changes the type of ticks from time_t to u32. We keep ticks as >> 32-bits as the function uses 32-bit arithmetic which would prove less >> expensive than 64-bit arithmetic and the function is expected to be >> called atleast once every 32 seconds. >> >> Signed-off-by: Heena Sirwani >> Reviewed-by: Arnd Bergmann >> Signed-off-by: Arnd Bergmann > > Applied to cgroup/for-4.5. > Acked