Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755099AbbDUPL0 (ORCPT ); Tue, 21 Apr 2015 11:11:26 -0400 Received: from mail-qg0-f48.google.com ([209.85.192.48]:33230 "EHLO mail-qg0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754819AbbDUPLY (ORCPT ); Tue, 21 Apr 2015 11:11:24 -0400 Date: Tue, 21 Apr 2015 11:11:19 -0400 From: Tejun Heo To: Alexey Dobriyan Cc: xiaoming.wang@intel.com, Linux Kernel , Mel Gorman , Andrew Morton Subject: Re: [PATCH] proc: move the adding option Ngid to the end of proc/PID/status Message-ID: <20150421151119.GB9455@htj.duckdns.org> References: <20150417142605.GA1954@htj.duckdns.org> <20150417151259.GA16743@htj.duckdns.org> <20150421140007.GA22502@p183.telecom.by> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150421140007.GA22502@p183.telecom.by> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1535 Lines: 32 On Tue, Apr 21, 2015 at 05:00:07PM +0300, Alexey Dobriyan wrote: > > 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. > > If there are TWO incorrect parsers, one for TracerPid, another for Ngid, > you CAN'T workaround it. And if you can't workaround you choose code > which was written first, namely, TracerPid one. Not when the code has been out for 1.5 years. Minimizing the disturbance is the better course of action. Look at the file. If you move ngid to the end now, it's gonna shift most of the file content, which is what caused the problem in the first place. We don't know what's out there which again was the same problem which triggered this thread in the first place. Why would you take the same amount of risk when you can fix the known issue with less amount of changes? Just put ngid after tracerpid. That way, we can fix the known problems while changing the offsets of only four fields. At this point, no change to the file layout is "right". Such thing isn't defined regardless of who came first. The only thing we can do is working around the known cases while minimizing possible impacts. Thanks. -- 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/