From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759181AbZCMTre (ORCPT ); Fri, 13 Mar 2009 15:47:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754173AbZCMTrZ (ORCPT ); Fri, 13 Mar 2009 15:47:25 -0400 Received: from hera.kernel.org ([140.211.167.34]:44164 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752785AbZCMTrY (ORCPT ); Fri, 13 Mar 2009 15:47:24 -0400 Message-ID: <49BAB7FF.4030107@kernel.org> Date: Fri, 13 Mar 2009 12:46:07 -0700 From: Yinghai Lu User-Agent: Thunderbird 2.0.0.19 (X11/20081227) MIME-Version: 1.0 To: Jaswinder Singh Rajput , mingo@elte.hu CC: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, linux-tip-commits@vger.kernel.org Subject: Re: [tip:x86/mtrr] x86: more MTRR debug printouts References: <49B9BA5A.40108@kernel.org> <1236958403.2646.1.camel@ht.satnam> <1236959121.2646.3.camel@ht.satnam> In-Reply-To: <1236959121.2646.3.camel@ht.satnam> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jaswinder Singh Rajput wrote: > On Fri, 2009-03-13 at 21:03 +0530, Jaswinder Singh Rajput wrote: >> On Fri, 2009-03-13 at 02:34 +0000, Yinghai Lu wrote: >>> Commit-ID: 8ad9790588ee2e69118b2b294ddab6f3f0379ad9 >>> Gitweb: http://git.kernel.org/tip/8ad9790588ee2e69118b2b294ddab6f3f0379ad9 >>> Author: Yinghai Lu >>> AuthorDate: Thu, 12 Mar 2009 18:43:54 -0700 >>> Commit: Ingo Molnar >>> CommitDate: Fri, 13 Mar 2009 02:52:18 +0100 >>> >>> x86: more MTRR debug printouts >>> >>> Impact: improve MTRR debugging messages >>> >>> There's still inefficiencies suspected with the MTRR sanitizing >>> code, so make sure we get all the info we need from a dmesg. >>> >>> - Remove unneeded mtrr_show >>> >>> (It will only printout one time by first cpu, so it is no big deal.) >>> >>> - Also print out directly from get_mtrr, because it doesn't update mtrr_state. >>> >>> Signed-off-by: Yinghai Lu >>> LKML-Reference: <49B9BA5A.40108@kernel.org> >>> Signed-off-by: Ingo Molnar >>> >>> >>> *base = 0; >>> @@ -407,6 +410,10 @@ static void generic_get_mtrr(unsigned int reg, unsigned long *base, >>> *size = -mask_lo; >>> *base = base_hi << (32 - PAGE_SHIFT) | base_lo >> PAGE_SHIFT; >>> *type = base_lo & 0xff; >>> + >>> + printk(KERN_DEBUG " get_mtrr: cpu%d reg%02d base=%010lx size=%010lx %s\n", >>> + smp_processor_id(), reg, *base, *size, >>> + mtrr_attrib_to_str(*type & 0xff)); >>> } >>> >> This leads to: >> >> Kernel failure message 1: >> BUG: using smp_processor_id() in preemptible [00000000] code: Xorg/1983 >> caller is generic_get_mtrr+0x12a/0x146 >> Pid: 1983, comm: Xorg Not tainted 2.6.29-rc8-tip #81 SMP PREEMPT Fri Mar >> 13 20:43:36 IST 2009 >> Call Trace: >> [] ? printk+0x14/0x16 >> [] debug_smp_processor_id+0xbb/0xd4 >> [] generic_get_mtrr+0x12a/0x146 >> [] mtrr_add_page+0x154/0x332 >> [] mtrr_file_add+0x72/0x86 >> [] mtrr_ioctl+0x21b/0x309 >> [] proc_reg_unlocked_ioctl+0x67/0xb2 >> [] ? mtrr_ioctl+0x0/0x309 >> [] ? proc_reg_unlocked_ioctl+0x0/0xb2 >> [] vfs_ioctl+0x27/0x6e >> [] do_vfs_ioctl+0x46f/0x4a9 >> [] ? do_mmap_pgoff+0x1e3/0x22e >> [] ? fget_light+0x40/0x130 >> [] sys_ioctl+0x34/0x61 >> [] sysenter_do_call+0x12/0x25 >> please check [PATCH] x86: fix get_mtrr warning about smp_processor_id with preempt Impact: fix warning Jaswinder noticed that there is warning about smp_processor_id() in get_mtrr try to fix it by use disable/enable to wrap it. Reported-by: Jaswinder Singh Rajput Signed-off-by: Yinghai Lu --- arch/x86/kernel/cpu/mtrr/generic.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) Index: linux-2.6/arch/x86/kernel/cpu/mtrr/generic.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/cpu/mtrr/generic.c +++ linux-2.6/arch/x86/kernel/cpu/mtrr/generic.c @@ -381,14 +381,18 @@ static void generic_get_mtrr(unsigned in { unsigned int mask_lo, mask_hi, base_lo, base_hi; unsigned int tmp, hi; + int cpu; /* * get_mtrr doesn't need to update mtrr_state, also it could be called * from any cpu, so try to print it out directly. */ + preempt_disable(); + cpu = smp_processor_id(); rdmsr(MTRRphysMask_MSR(reg), mask_lo, mask_hi); if ((mask_lo & 0x800) == 0) { + preempt_enable(); /* Invalid (i.e. free) range */ *base = 0; *size = 0; @@ -397,6 +401,7 @@ static void generic_get_mtrr(unsigned in } rdmsr(MTRRphysBase_MSR(reg), base_lo, base_hi); + preempt_enable(); /* Work out the shifted address mask. */ tmp = mask_hi << (32 - PAGE_SHIFT) | mask_lo >> PAGE_SHIFT; @@ -419,7 +424,7 @@ static void generic_get_mtrr(unsigned in *type = base_lo & 0xff; printk(KERN_DEBUG " get_mtrr: cpu%d reg%02d base=%010lx size=%010lx %s\n", - smp_processor_id(), reg, *base, *size, + cpu, reg, *base, *size, mtrr_attrib_to_str(*type & 0xff)); }