From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2992708AbcB1A5f (ORCPT ); Sat, 27 Feb 2016 19:57:35 -0500 Received: from mail-ig0-f194.google.com ([209.85.213.194]:36341 "EHLO mail-ig0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756866AbcB1A5e (ORCPT ); Sat, 27 Feb 2016 19:57:34 -0500 MIME-Version: 1.0 In-Reply-To: <1082926946.10326.1456619994590.JavaMail.zimbra@efficios.com> References: <1456270120-7560-1-git-send-email-mathieu.desnoyers@efficios.com> <1150363257.9781.1456533630895.JavaMail.zimbra@efficios.com> <56D14132.5050100@zytor.com> <2053850250.10158.1456582501604.JavaMail.zimbra@efficios.com> <20160227145809.GD6356@twins.programming.kicks-ass.net> <1401667361.10273.1456617236327.JavaMail.zimbra@efficios.com> <1082926946.10326.1456619994590.JavaMail.zimbra@efficios.com> Date: Sat, 27 Feb 2016 16:57:32 -0800 X-Google-Sender-Auth: NV1mYneH0F9yIv-pPsgbUkdZ6lQ Message-ID: Subject: Re: [PATCH v4 1/5] getcpu_cache system call: cache CPU number of running thread From: Linus Torvalds To: Mathieu Desnoyers Cc: Ben Maurer , Thomas Gleixner , Ingo Molnar , Russell King , linux-api , Andrew Morton , Michael Kerrisk , Dave Watson , rostedt , Andy Lutomirski , Will Deacon , "Paul E. McKenney" , Chris Lameter , Andi Kleen , Josh Triplett , Paul Turner , Linux Kernel Mailing List , Catalin Marinas , Andrew Hunter , "H. Peter Anvin" , Peter Zijlstra Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Feb 27, 2016 at 4:39 PM, Mathieu Desnoyers wrote: > > > I'm particularly interested to know what are the best practices to > deal with an extensible bitfield (the features mask). cpu_set_t > and sigmask each seem to do their own thing. Quite frankly, why would the kernel ever touch anything else? And if the kernel doesn't touch anything else, why make it part of the ABI? I don't see why the kernel would ever want to have a more complex interface. Explain. Linus