Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754334AbbDUITu (ORCPT ); Tue, 21 Apr 2015 04:19:50 -0400 Received: from mga02.intel.com ([134.134.136.20]:34551 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753056AbbDUITq convert rfc822-to-8bit (ORCPT ); Tue, 21 Apr 2015 04:19:46 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.11,614,1422950400"; d="scan'208";a="698436929" From: "Wang, Xiaoming" To: Tejun Heo , Alexey Dobriyan CC: Linux Kernel , Mel Gorman , Andrew Morton , "Zhang, Dongxing" Subject: RE: [PATCH] proc: move the adding option Ngid to the end of proc/PID/status Thread-Topic: [PATCH] proc: move the adding option Ngid to the end of proc/PID/status Thread-Index: AQHQeRG8iNcmFn2F5EmN3jO2vltknZ1QvKCAgAALIYCAAAH5gIAGWZpA Date: Tue, 21 Apr 2015 08:19:40 +0000 Message-ID: References: <20150417142605.GA1954@htj.duckdns.org> <20150417151259.GA16743@htj.duckdns.org> In-Reply-To: <20150417151259.GA16743@htj.duckdns.org> Accept-Language: zh-CN, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1886 Lines: 48 Dear tejun > -----Original Message----- > From: Tejun Heo [mailto:htejun@gmail.com] On Behalf Of Tejun Heo > Sent: Friday, April 17, 2015 11:13 PM > To: Alexey Dobriyan > Cc: Wang, Xiaoming; Linux Kernel; Mel Gorman; Andrew Morton > Subject: Re: [PATCH] proc: move the adding option Ngid to the end of > proc/PID/status > > On Fri, Apr 17, 2015 at 06:05:55PM +0300, Alexey Dobriyan wrote: > > Moving Ngid to the end of file minimizes risk of breakage. > > Hmmm... how so? The only reason for changing the position is because there's > this specific breakage. The goal should be working around that specific case > while keeping the impact minimum on everyone else. > It doesn't matter whether the initial change was good or bad, the kernel w/ the > new layout is already out in the wild and it has been out there for a while. How > is risking changing offsets on most of the fields on those kernels a good idea? > Mimize the changes to work around the specific case. > Do you mean we should to update the every application under this new order? > > Correctly written code doesn't care. > > Code which hardcodes layout won't notice. > > Huh? Code which hardcodes layout since 1.5 years ago will definitely notice. > As I mentioned before not all user update the kernel so frequently. They will met this issue, if update to the 3.13, The application failed to use which may run well previously. > > It would be OK argument if gentlemen from Intel send "let's > > futureproof and move Ngid because someone might depend on exact > position" patch. > > > > Primum non nocere. > > ajlkjaeligjlakd lakjeilgjal flekjfa. > > -- > tejun -- 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/