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 <[email protected]> > Cc: Thomas Gleixner <[email protected]> > Cc: Ingo Molnar <[email protected]> > Cc: "H. Peter Anvin" <[email protected]> > Cc: [email protected] > Cc: Andy Lutomirski <[email protected]> > Cc: Borislav Petkov <[email protected]> > Cc: Denys Vlasenko <[email protected]> > Cc: Dave Hansen <[email protected]> > Cc: Igor Mammedov <[email protected]> > Cc: Fenghua Yu <[email protected]> > --- > 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); > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
