Re: [PATCH] x86,mm: print likely CPU at segfault time

From: Thomas Gleixner
Date: Wed Jul 21 2021 - 16:38:40 EST


On Mon, Jul 19 2021 at 15:34, Rik van Riel wrote:

> On Mon, 2021-07-19 at 12:20 -0700, Dave Hansen wrote:
>
>> If it's as trivial as:
>>
>>         printk(KERN_CONT " on cpu/core %d/%d",
>>                 raw_smp_processor_id(),
>>                 topology_core_id(raw_smp_processor_id()));
>>
>> it would be handy.  But, it's also not hard to look at 10 segfaults,
>> see
>> that they happened only on 2 CPUs and realize that hyperthreading is
>> enabled.
>
> One problem with topology_core_id() is that that, on a
> multi-socket system, the core number may not be unique.

Just add topology_physical_package_id() and you have a complete picture.

Thanks,

tglx