From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758528Ab2CFH54 (ORCPT ); Tue, 6 Mar 2012 02:57:56 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:32877 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758329Ab2CFH5z (ORCPT ); Tue, 6 Mar 2012 02:57:55 -0500 Date: Tue, 6 Mar 2012 08:57:40 +0100 From: Ingo Molnar To: Andrew Morton Cc: tglx@linutronix.de, hpa@zytor.com, alex.shi@intel.com, cl@gentwo.org, sfr@canb.auug.org.au, tj@kernel.org, linux-kernel@vger.kernel.org, Linus Torvalds , Peter Zijlstra Subject: Re: [patch 5/8] x86: use this_cpu_xxx to replace percpu_xxx funcs Message-ID: <20120306075740.GF23669@elte.hu> References: <20120305230515.A9238A02AE@akpm.mtv.corp.google.com> <20120306074601.GD23669@elte.hu> <20120305235532.28f407bf.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120305235532.28f407bf.akpm@linux-foundation.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andrew Morton wrote: > On Tue, 6 Mar 2012 08:46:01 +0100 Ingo Molnar wrote: > > > Will percpu_write() be removed altogether? If so then the > > changelog should say *that*, and explain that on x86 this is a > > simple renaming of the API, not a long explanation about > > scenarios that don't actually matter. > > > > If percpu_write() is not being removed then I don't see how this > > patch is an improvement: it's supposed to result in the same > > instructions being emitted, and __this_cpu_write() et al are > > distinctly longer to write ... > > > > So what's the plan here? > > All percpu_xxx() functions get removed. Fair enough - then please see my namespace comments for the other patch, before we start spreading these APIs to hundreds of places ... Also, IMHO the lack of debugging API is troubling as well. Thomas found a couple of really, really hairy this_cpu related bugs. Thanks, Ingo