From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761257AbYDYJLm (ORCPT ); Fri, 25 Apr 2008 05:11:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758505AbYDYJLe (ORCPT ); Fri, 25 Apr 2008 05:11:34 -0400 Received: from fg-out-1718.google.com ([72.14.220.156]:41990 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758267AbYDYJLc (ORCPT ); Fri, 25 Apr 2008 05:11:32 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject:references:in-reply-to:content-type:content-transfer-encoding; b=rb7tu2MI9M71y2BKRPqDJspXB4nK+AKA7NfaSlewn6/5w5u5vzszESN+z+YZj7+bJ12HyXrmVyh/o1Sp1jzFMsFwhQs5DyphKbbePwEA460EDEtkBcNs/6Yd3Ok+wx0ee0dz0ZbM6p3wsPzUMoJNn0NmzIaAJ0IizOsHuvyNggI= Message-ID: <4811A03A.7010109@googlemail.com> Date: Fri, 25 Apr 2008 11:11:22 +0200 From: Gabriel C User-Agent: Thunderbird 2.0.0.12 (X11/20080227) MIME-Version: 1.0 To: Ingo Molnar CC: Priit Laes , linux-kernel , Jack Steiner Subject: Re: [REGRESSION] x86: support for new UV apic References: <1209098600.3707.13.camel@localhost> <20080425064405.GA23043@elte.hu> In-Reply-To: <20080425064405.GA23043@elte.hu> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ingo Molnar wrote: > * Priit Laes wrote: > >> Hey, >> >> I am getting two following warnings (probable one per each CPU core) >> using the latest Linus's git: >> >> WARNING: at arch/x86/kernel/genapic_64.c:86 read_apic_id+0x30/0x62() >> Modules linked in: >> Pid: 1, comm: swapper Not tainted 2.6.25-03563-gf7288b1 #20 > > thanks - could you check the patch below, does it fix the warnings? Hi Ingo , I got the same warning on my Core2Quad Q9300 box , your patch fixes the warning for me. > > Ingo > > ---------------> > Subject: x86: disable preemption in native_smp_prepare_cpus > From: Ingo Molnar > Date: Fri Apr 18 11:07:10 CEST 2008 > > Priit Laes reported the following warning: > > Call Trace: > [] warn_on_slowpath+0x51/0x63 > [] sys_ioctl+0x2d/0x5d > [] _spin_lock+0xe/0x24 > [] task_rq_lock+0x3d/0x73 > [] set_cpu_sibling_map+0x336/0x350 > [] read_apic_id+0x30/0x62 > [] verify_local_APIC+0x90/0x138 > [] native_smp_prepare_cpus+0x1f9/0x305 > [] kernel_init+0x59/0x2d9 > [] _spin_unlock_irq+0x11/0x2b > [] child_rip+0xa/0x12 > [] kernel_init+0x0/0x2d9 > [] child_rip+0x0/0x12 > > fix this by generally disabling preemption in native_smp_prepare_cpus(). > > Reported-and-bisected-by: Priit Laes > Signed-off-by: Ingo Molnar > Signed-off-by: Thomas Gleixner > --- > arch/x86/kernel/smpboot.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > Index: linux-x86.q/arch/x86/kernel/smpboot.c > =================================================================== > --- linux-x86.q.orig/arch/x86/kernel/smpboot.c > +++ linux-x86.q/arch/x86/kernel/smpboot.c > @@ -1181,6 +1181,7 @@ static void __init smp_cpu_index_default > */ > void __init native_smp_prepare_cpus(unsigned int max_cpus) > { > + preempt_disable(); > nmi_watchdog_default(); > smp_cpu_index_default(); > current_cpu_data = boot_cpu_data; > @@ -1197,7 +1198,7 @@ void __init native_smp_prepare_cpus(unsi > if (smp_sanity_check(max_cpus) < 0) { > printk(KERN_INFO "SMP disabled\n"); > disable_smp(); > - return; > + goto out; > } > > preempt_disable(); > @@ -1237,6 +1238,8 @@ void __init native_smp_prepare_cpus(unsi > printk(KERN_INFO "CPU%d: ", 0); > print_cpu_info(&cpu_data(0)); > setup_boot_clock(); > +out: > + preempt_enable(); > } > /* > * Early setup to make printk work. Regards, Gabriel