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 adds a local copy of the x86_model_id field and modifies the value there so that the output in dmesg still looks like smpboot: CPU0: AMD Opteron(TM) Processor 6272 (fam: 15, model: 01, stepping: 02) and the x86_model_id field is correct across all processors: [thetango@prarit ~]# grep "^model name" /proc/cpuinfo | uniq -c | sed 's/\ /_/g' _____64_model_name :_AMD_Opteron(TM)_Processor_6272_________________ 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: Peter P Waskiewicz Jr <[email protected]> Cc: Igor Mammedov <[email protected]> Cc: Fenghua Yu <[email protected]> --- arch/x86/kernel/cpu/common.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index a62cf04..61ac5c3 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1110,6 +1110,7 @@ __setup("noclflush", setup_noclflush); void print_cpu_info(struct cpuinfo_x86 *c) { const char *vendor = NULL; + char x86_model_id[64]; if (c->x86_vendor < X86_VENDOR_NUM) { vendor = this_cpu->c_vendor; @@ -1121,9 +1122,10 @@ void print_cpu_info(struct cpuinfo_x86 *c) if (vendor && !strstr(c->x86_model_id, vendor)) printk(KERN_CONT "%s ", vendor); - if (c->x86_model_id[0]) - printk(KERN_CONT "%s", strim(c->x86_model_id)); - else + if (c->x86_model_id[0]) { + strcpy(x86_model_id, c->x86_model_id); + printk(KERN_CONT "%s", strim(x86_model_id)); + } else printk(KERN_CONT "%d86", c->x86); printk(KERN_CONT " (fam: %02x, model: %02x", c->x86, c->x86_model); -- 1.7.9.3 -- 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/
