Re: [PATCH v3] powerpc/64: system call implement the bulk of the logic in C

[Christophe Leroy <christophe.leroy@c-s.fr>]

Le 05/09/2019 à 19:46, Michal Suchánek a écrit :
> On Thu, 5 Sep 2019 15:25:31 +0000
> Christophe Leroy <christophe.leroy@c-s.fr> wrote:
> 
>> On 09/05/2019 12:35 PM, Nicholas Piggin wrote:
>>> System call entry and particularly exit code is beyond the limit of what
>>> is reasonable to implement in asm.
>>>
>>> This conversion moves all conditional branches out of the asm code,
>>> except for the case that all GPRs should be restored at exit.
>>>
>>> Null syscall test is about 5% faster after this patch, because the exit
>>> work is handled under local_irq_disable, and the hard mask and pending
>>> interrupt replay is handled after that, which avoids games with MSR.
>>>
>>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>>
>> Cannot apply it on latest powerpc/merge. On what does that apply ?
> 
> The v2 series had 4 patches so presumably the previous 3 are missing
> here.
> 

Yes indeed, the first two patches are already merged, so applying patch 
3 of that series allows to apply this patch.

Christophe