Re: [PATCH] powerpc/ftrace: Enable C Version of recordmcount

[Christophe Leroy]

Le 08/05/2019 Ã 02:45, Michael Ellerman a ÃcritÂ:
> Christophe Leroy <christophe.leroy@xxxxxx> writes:
> > Selects HAVE_C_RECORDMCOUNT to use the C version of the recordmcount
> > intead of the old Perl Version of recordmcount.
> >
> > This should improve build time. It also seems like the old Perl Version
> > misses some calls to _mcount that the C version finds.
>
> That would make this a bug fix possibly for stable even.
>
> Any more details on what the difference is, is it just some random
> subset of functions or some pattern?

I have not been able to identify any pattern. Will add a few details in 
the 'issue' on github.

Christophe

> cheers
>
> > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> > index 2711aac24621..d87de4f9da61 100644
> > --- a/arch/powerpc/Kconfig
> > +++ b/arch/powerpc/Kconfig
> > @@ -180,6 +180,7 @@ config PPC
> >   	select HAVE_ARCH_NVRAM_OPS
> >   	select HAVE_ARCH_SECCOMP_FILTER
> >   	select HAVE_ARCH_TRACEHOOK
> > +	select HAVE_C_RECORDMCOUNT
> >   	select HAVE_CBPF_JIT			if !PPC64
> >   	select HAVE_STACKPROTECTOR		if PPC64 && $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r13)
> >   	select HAVE_STACKPROTECTOR		if PPC32 && $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r2)
> > --
> > 2.13.3