From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753562AbbCaJNd (ORCPT ); Tue, 31 Mar 2015 05:13:33 -0400 Received: from mail-wi0-f179.google.com ([209.85.212.179]:36341 "EHLO mail-wi0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752372AbbCaJN3 (ORCPT ); Tue, 31 Mar 2015 05:13:29 -0400 Date: Tue, 31 Mar 2015 11:13:24 +0200 From: Ingo Molnar To: Peter Zijlstra Cc: Mike Galbraith , David Ahern , linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH] sched: Add cpu based entries to debugfs Message-ID: <20150331091324.GA16810@gmail.com> References: <1427681613-98163-1-git-send-email-david.ahern@oracle.com> <20150330074452.GM23123@twins.programming.kicks-ass.net> <1427703963.7560.3.camel@gmx.de> <20150330082812.GP23123@twins.programming.kicks-ass.net> <1427704994.7560.14.camel@gmx.de> <20150330091841.GR23123@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150330091841.GR23123@twins.programming.kicks-ass.net> 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 * Peter Zijlstra wrote: > On Mon, Mar 30, 2015 at 10:43:14AM +0200, Mike Galbraith wrote: > > > I think it would be a good thing if we can get away with it, but I > > also think you could safely bet your life that somebody will > > squeak. > > The thing I worry most about is that squeaking only happening 5 > years later :/ So lets start by keeping the sysctl thing with the very scheduler-internal names, but all zeroes and no effect of any change - i.e. a dead API in all but appearance. I don't think there's any legitimate use of those, beyond debugging, as we could change the internal implementation anymore and moot many of those flags. So lets trigger the squeaking that way. If any complaint comes in beyond 1-2 kernel releases then I don't think it's a regression, it turns into a feature request ... Thanks, Ingo