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

Michal Suchánek msuchanek at suse.de
Fri Sep 6 03:46:38 AEST 2019


On Thu, 5 Sep 2019 15:25:31 +0000
Christophe Leroy <christophe.leroy at 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 at 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.

Thanks

Michal


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