From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754593Ab0JRMsc (ORCPT ); Mon, 18 Oct 2010 08:48:32 -0400 Received: from mail.openrapids.net ([64.15.138.104]:53703 "EHLO blackscsi.openrapids.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753509Ab0JRMsb (ORCPT ); Mon, 18 Oct 2010 08:48:31 -0400 Date: Mon, 18 Oct 2010 08:48:28 -0400 From: Mathieu Desnoyers To: Peter Zijlstra Cc: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, rostedt@goodmis.org, tglx@linutronix.de, jbaron@redhat.com, linux-tip-commits@vger.kernel.org Subject: Re: [tip:perf/core] jump label: x86 support Message-ID: <20101018124828.GB25148@Krystal> References: <1287400675.29097.1550.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1287400675.29097.1550.camel@twins> X-Editor: vi X-Info: http://www.efficios.com X-Operating-System: Linux/2.6.26-2-686 (i686) X-Uptime: 08:41:05 up 25 days, 16:43, 1 user, load average: 0.11, 0.15, 0.28 User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Peter Zijlstra (peterz@infradead.org) wrote: > On Fri, 2010-09-24 at 09:01 +0000, tip-bot for Jason Baron wrote: > > +void arch_jump_label_transform(struct jump_entry *entry, > > + enum jump_label_type type) > > +{ > > + union jump_code_union code; > > + > > + if (type == JUMP_LABEL_ENABLE) { > > + code.jump = 0xe9; > > + code.offset = entry->target - > > + (entry->code + JUMP_LABEL_NOP_SIZE); > > + } else > > + memcpy(&code, ideal_nop5, JUMP_LABEL_NOP_SIZE); > > + get_online_cpus(); > > + mutex_lock(&text_mutex); > > + text_poke_smp((void *)entry->code, &code, JUMP_LABEL_NOP_SIZE); > > + mutex_unlock(&text_mutex); > > + put_online_cpus(); > > +} > > hpa, mathieu, what's the status of stop_machine less text poking? > Because the above basically means we have to disable architecture > jump_label support for -rt. hpa got an unofficial answer from Intel OTC, that states the stop_machine-less text poking procedure is valid. http://lkml.org/lkml/2010/1/12/300 We are still waiting for the "official" blessing though. Thanks, Mathieu -- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com