Re: [PATCH v2 0/4] powerpc/64: syscalls in C

[Nicholas Piggin <npiggin@gmail.com>]

Christophe Leroy's on August 28, 2019 7:06 pm:
> 
> 
> Le 27/08/2019 à 15:55, Nicholas Piggin a écrit :
>> Accounted for some feedback.
>> 
>> Nicholas Piggin (4):
>>    powerpc: convert to copy_thread_tls
>>    powerpc/64: remove support for kernel-mode syscalls
>>    powerpc/64: system call remove non-volatile GPR save optimisation
>>    powerpc/64: system call implement the bulk of the logic in C
> 
> Would it be possible to split in the following parts:
> 
> 1/ Implement in C whatever can be implemented without removing 
> non-volatile GPR save optimisation
> 2/ Remove non-volatile GPR save optimisation
> 3/ Implement in C everything else

Hmm. I'll have a look but I would rather not go back and add the
intermediate state I was hoping to avoid. I'll think about it and
if it's not too difficult I will try to add something. I have an
idea.

With your nvregs performance test on ppc32, are you doing the
nvgpr restore? The fast path should be able to avoid that.

Thanks,
Nick