From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754783AbYFUVze (ORCPT ); Sat, 21 Jun 2008 17:55:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753479AbYFUVz1 (ORCPT ); Sat, 21 Jun 2008 17:55:27 -0400 Received: from ug-out-1314.google.com ([66.249.92.173]:49287 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752513AbYFUVz0 (ORCPT ); Sat, 21 Jun 2008 17:55:26 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:to:cc:subject:message-id:mime-version:content-type :content-disposition:in-reply-to:user-agent:from; b=WscpXVW1HacRtpA+KicaXKl7dGb+fbh12q18h6hZC+8ERueNnibS6J8moWqztBI4Cg 0sixeLke4Rw5+1g0rAgoUoBWCnfvXm6G7zqOMQSTuwIRmQ6hmqS/fl1pmRkBJEbd7jPr isdxQVRYQSrqs++JbDrvKWW1gjFMn4rbieiLo= Date: Sat, 21 Jun 2008 23:55:18 +0200 To: Ingo Molnar , Philippe Elie Cc: oprofile-list@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: [PATCH] x86/oprofile: disable preemption in nmi_shutdown Message-ID: <20080621215518.GA5715@damson.getinternet.no> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080621182805.GA27417@damson.getinternet.no> User-Agent: Mutt/1.5.17 (2007-11-01) From: Vegard Nossum Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Does this look correct? I didn't really play with preemption before, but as far as I can tell, this is the right thing to do. I don't really get why model->shutdown(msrs) is done only for one of the CPUs, but my patch assumes that this is correct. (If that had been done from inside nmi_shutdown() for each CPU, we wouldn't have had to get the cpu var, and not needed to disable preemption.) Please comment :-) Vegard From: Vegard Nossum Date: Sat, 21 Jun 2008 23:44:19 +0200 Subject: [PATCH] x86/oprofile: disable preemption in nmi_shutdown BUG: using smp_processor_id() in preemptible [00000000] code: oprofiled/27301 caller is nmi_shutdown+0x11/0x60 Pid: 27301, comm: oprofiled Not tainted 2.6.26-rc7 #25 [] debug_smp_processor_id+0xbd/0xc0 [] nmi_shutdown+0x11/0x60 [] oprofile_shutdown+0x2a/0x60 Note that we don't need this for the other functions, since they are all called with on_each_cpu() (which disables preemption for us anyway). Signed-off-by: Vegard Nossum --- arch/x86/oprofile/nmi_int.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-) diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c index cc48d3f..4a177b4 100644 --- a/arch/x86/oprofile/nmi_int.c +++ b/arch/x86/oprofile/nmi_int.c @@ -269,12 +269,16 @@ static void nmi_cpu_shutdown(void *dummy) static void nmi_shutdown(void) { - struct op_msrs *msrs = &__get_cpu_var(cpu_msrs); + struct op_msrs *msrs; + + preempt_disable(); + msrs = &__get_cpu_var(cpu_msrs); nmi_enabled = 0; on_each_cpu(nmi_cpu_shutdown, NULL, 0, 1); unregister_die_notifier(&profile_exceptions_nb); model->shutdown(msrs); free_msrs(); + preempt_enable(); } static void nmi_cpu_start(void *dummy) -- 1.5.4.1