From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932545AbbERWFP (ORCPT ); Mon, 18 May 2015 18:05:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37033 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932395AbbERWFL (ORCPT ); Mon, 18 May 2015 18:05:11 -0400 Message-ID: <555A6215.1050907@redhat.com> Date: Mon, 18 May 2015 18:05:09 -0400 From: Prarit Bhargava User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20131028 Thunderbird/17.0.10 MIME-Version: 1.0 To: Prarit Bhargava CC: linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Andy Lutomirski , Borislav Petkov , Denys Vlasenko , Dave Hansen , Igor Mammedov , Fenghua Yu Subject: Re: [PATCH] x86, cpuinfo remove cpu_data x86_model_id trailing whitespace References: <1431986509-25448-1-git-send-email-prarit@redhat.com> In-Reply-To: <1431986509-25448-1-git-send-email-prarit@redhat.com> 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 On 05/18/2015 06:01 PM, Prarit Bhargava wrote: > When comparing 'model name' fields in /proc/cpuinfo it was noticed that > a simple test comparing the model name fields was failing. After some > simple investigation it was noticed that, in fact, the model name fields > are different for each processor. Processor 0's model name field had > white space removed, while the other processors did not. > > Another way of seeing this behaviour is to convert spaces into underscores > in the output of /proc/cpuinfo, > > [thetango@prarit ~]# grep "^model name" /proc/cpuinfo | uniq -c | sed 's/\ /_/g' > ______1_model_name :_AMD_Opteron(TM)_Processor_6272 > _____63_model_name :_AMD_Opteron(TM)_Processor_6272_________________ > > which shows two different model name fields even though they should be the > same. > > This occurs because the kernel calls strim() on cpu 0's x86_model_id field > to output a pretty message to the console in print_cpu_info(), and as a > result truncates the whitespace at the end of the x86_model_id field. > > The x86_model_id field should be the same for the same processors. This > patch removes traliing space on every processor's x86_model_id field to make > them consistent and maintains the correct output for print_cpu_info(): > > smpboot: CPU0: AMD Opteron(TM) Processor 6272 (fam: 15, model: 01, stepping: 02) > > The x86_model_id field is correct and has no whitespace across all processors: > > [thetango@prarit ~]# grep "^model name" /proc/cpuinfo | uniq -c | sed 's/\ /_/g' > _____64_model_name :_AMD_Opteron(TM)_Processor_6272 > Nack this ... hpa has suggested that I backwards search from the 48th character for the first non-null ... I'll put together a new patch. P. > Signed-off-by: Prarit Bhargava > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: "H. Peter Anvin" > Cc: x86@kernel.org > Cc: Andy Lutomirski > Cc: Borislav Petkov > Cc: Denys Vlasenko > Cc: Dave Hansen > Cc: Igor Mammedov > Cc: Fenghua Yu > --- > arch/x86/kernel/cpu/common.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c > index a62cf04..fa771bb 100644 > --- a/arch/x86/kernel/cpu/common.c > +++ b/arch/x86/kernel/cpu/common.c > @@ -443,6 +443,7 @@ static void get_model_name(struct cpuinfo_x86 *c) > while (q <= &c->x86_model_id[48]) > *q++ = '\0'; /* Zero-pad the rest */ > } > + strim(c->x86_model_id); > } > > void cpu_detect_cache_sizes(struct cpuinfo_x86 *c) > @@ -1122,7 +1123,7 @@ void print_cpu_info(struct cpuinfo_x86 *c) > printk(KERN_CONT "%s ", vendor); > > if (c->x86_model_id[0]) > - printk(KERN_CONT "%s", strim(c->x86_model_id)); > + printk(KERN_CONT "%s", c->x86_model_id); > else > printk(KERN_CONT "%d86", c->x86); > >