From: Prarit Bhargava <[email protected]> When comparing the 'model name' field of each core in /proc/cpuinfo it was noticed that there is a whitespace difference between the cores' model names.
After some quick investigation it was noticed that the model name fields were actually different -- processor 0's model name field had trailing whitespace 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 the discrepancy. 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 strips the whitespace at the end of the ->x86_model_id field. But, the ->x86_model_id field should be the same for the all identical CPUs in the box. Thus, we need to remove both leading and trailing whitespace. As a result, the print_cpu_info() output looks like smpboot: CPU0: AMD Opteron(TM) Processor 6272 (fam: 15, model: 01, stepping: 02) and the x86_model_id field is correct on all processors on AMD platforms: _____64_model_name :_AMD_Opteron(TM)_Processor_6272 Output is still correct on an Intel box: ____144_model_name :_Intel(R)_Xeon(R)_CPU_E7-8890_v3_@_2.50GHz Signed-off-by: Prarit Bhargava <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Igor Mammedov <[email protected]> Cc: Fenghua Yu <[email protected]> Cc: Brian Gerst <[email protected]> Cc: lkml <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Borislav Petkov <[email protected]> --- arch/x86/kernel/cpu/common.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index a62cf04dac8a..41a8e9cb30bc 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -419,7 +419,6 @@ static const struct cpu_dev *cpu_devs[X86_VENDOR_NUM] = {}; static void get_model_name(struct cpuinfo_x86 *c) { unsigned int *v; - char *p, *q; if (c->extended_cpuid_level < 0x80000004) return; @@ -431,18 +430,10 @@ static void get_model_name(struct cpuinfo_x86 *c) c->x86_model_id[48] = 0; /* - * Intel chips right-justify this string for some dumb reason; - * undo that brain damage: + * Remove leading whitespace on Intel processors and trailing + * whitespace on AMD processors. */ - p = q = &c->x86_model_id[0]; - while (*p == ' ') - p++; - if (p != q) { - while (*p) - *q++ = *p++; - while (q <= &c->x86_model_id[48]) - *q++ = '\0'; /* Zero-pad the rest */ - } + memmove(c->x86_model_id, strim(c->x86_model_id), 48); } void cpu_detect_cache_sizes(struct cpuinfo_x86 *c) @@ -1122,7 +1113,7 @@ 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); -- 1.9.0.258.g00eda23 -- 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/
