Re: [PATCH 2/2] KVM: selftests: Use getcpu() instead of sched_getcpu() in rseq_test

From: Florian Weimer
Date: Tue Aug 09 2022 - 03:17:37 EST


* Florian Weimer:

> * Gavin Shan:
>
>> sched_getcpu() is glibc dependent and it can simply return the CPU
>> ID from the registered rseq information, as Florian Weimer pointed.
>> In this case, it's pointless to compare the return value from
>> sched_getcpu() and that fetched from the registered rseq information.
>>
>> Fix the issue by replacing sched_getcpu() with getcpu(), as Florian
>> suggested. The comments are modified accordingly.
>
> Note that getcpu was added in glibc 2.29, so perhaps you need to perform
> a direct system call?

One more thing: syscall(__NR_getcpu) also has the advantage that it
wouldn't have to be changed again if node IDs become available via rseq
and getcpu is implemented using that.

Thanks,
Florian