Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753460Ab2BVPv2 (ORCPT ); Wed, 22 Feb 2012 10:51:28 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:57379 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751042Ab2BVPv0 (ORCPT ); Wed, 22 Feb 2012 10:51:26 -0500 Date: Wed, 22 Feb 2012 16:51:10 +0100 From: Ingo Molnar To: "H. Peter Anvin" Cc: Steven Rostedt , Jason Baron , a.p.zijlstra@chello.nl, mathieu.desnoyers@efficios.com, davem@davemloft.net, ddaney.cavm@gmail.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, Linus Torvalds Subject: Re: [PATCH 00/10] jump label: introduce very_[un]likely + cleanups + docs Message-ID: <20120222155110.GB28314@elte.hu> References: <4F43F9F0.4000605@zytor.com> <20120221202019.GB2381@redhat.com> <1329856745.25686.72.camel@gandalf.stny.rr.com> <20120222073251.GB17291@elte.hu> <20120222075334.GA25053@elte.hu> <7479958c-1932-4ced-a7a4-53ac6ea3a38e@email.android.com> <20120222081855.GB25318@elte.hu> <4F45050B.4080001@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4F45050B.4080001@zytor.com> 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 Content-Length: 1061 Lines: 40 * H. Peter Anvin wrote: > On 02/22/2012 12:18 AM, Ingo Molnar wrote: > > > > For example could you tell *at a glance* what this does: > > > > + if (!static_branch_def_false(&perf_sched_events.key)) > > > > ? > > Yes. [...] You have specially built eyes I guess - congrats, you are member of the 1% :-) > [...] Unlike > > > + if (very_unlikely(&perf_sched_events.key)) > > ... which is actively misleading. Misleading in what way? It clearly conveys that the slowpath that follows is a slowpath, that what follows is 'very unlikely'. This is how all current kernel code is using these facilities. If you have a new usecase (CPU feature flags) then you should outline that, instead of expecting something of current usecases that they are clearly not ... Thanks, Ingo -- 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/