Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753137Ab2BVPQB (ORCPT ); Wed, 22 Feb 2012 10:16:01 -0500 Received: from terminus.zytor.com ([198.137.202.10]:50726 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751921Ab2BVPQA (ORCPT ); Wed, 22 Feb 2012 10:16:00 -0500 Message-ID: <4F450696.6010409@zytor.com> Date: Wed, 22 Feb 2012 07:15:34 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0) Gecko/20120131 Thunderbird/10.0 MIME-Version: 1.0 To: Steven Rostedt CC: Ingo Molnar , 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 References: <20120222065016.GA16923@elte.hu> <4F44934B.2000808@zytor.com> <20120222072538.GA17291@elte.hu> <4F449ACF.3040807@zytor.com> <20120222074839.GA24890@elte.hu> <20120222080659.GA25318@elte.hu> <1329916920.25686.79.camel@gandalf.stny.rr.com> <20120222133404.GA14085@elte.hu> <1329918881.25686.92.camel@gandalf.stny.rr.com> <20120222145614.GA2491@elte.hu> <1329923533.25686.106.camel@gandalf.stny.rr.com> In-Reply-To: <1329923533.25686.106.camel@gandalf.stny.rr.com> X-Enigmail-Version: 1.3.5 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1137 Lines: 32 On 02/22/2012 07:12 AM, Steven Rostedt wrote: > On Wed, 2012-02-22 at 15:56 +0100, Ingo Molnar wrote: > >>> Because it really just looks like a stronger "unlikely()" and >>> fundamentally it really isn't. [...] >> >> Well, the fact is that right now it *is* a stronger unlikely() >> on architectures that have jump-labels and it's mapped to >> unlikely() on others. >> > > Has gcc been fix to make it truly an unlikely case and remove the "jmp; > jmp" problem of before? I'm still using gcc 4.6.0 which has the > following code for a tracepoint (example is the > trace_sched_migrate_task(). > No, the jmp jmp problem still exists... I have discussed it with the gcc folks and they have an idea for how to fix it, but I haven't even gotten around to filing a formal RFE. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- 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/