2019-05-07 13:33:34

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH] powerpc/ftrace: Enable C Version of recordmcount

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.

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/Kconfig | 1 +
1 file changed, 1 insertion(+)

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


2019-05-08 00:46:31

by Michael Ellerman

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

Christophe Leroy <[email protected]> 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?

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

2019-05-09 11:29:13

by Christophe Leroy

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



Le 08/05/2019 à 02:45, Michael Ellerman a écrit :
> Christophe Leroy <[email protected]> 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

2019-07-03 14:27:41

by Michael Ellerman

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

On Tue, 2019-05-07 at 13:31:38 UTC, Christophe Leroy wrote:
> 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.
>
> Signed-off-by: Christophe Leroy <[email protected]>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/f079bb3c5f2978b2c1a13098ab2a8c32e5d1ee3d

cheers