linux-next: manual merge of the percpu tree with the asm-generic tree

linux-next: manual merge of the percpu tree with the asm-generic tree

[Stephen Rothwell]

Hi all,

Today's linux-next merge of the percpu tree got a conflict in:

  include/asm-generic/percpu.h

between commit:

  acbdf0e98066 ("percpu: make this_cpu_generic_read notrace")

from the asm-generic tree and commit:

  1b5ca1212742 ("percpu: improve generic percpu modify-return implementation")

from the percpu tree.

I fixed it up (see below) and can carry the fix as necessary. This
is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging.  You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.

-- 
Cheers,
Stephen Rothwell

diff --cc include/asm-generic/percpu.h
index 70fefec69e61,40e887068da2..000000000000
--- a/include/asm-generic/percpu.h
+++ b/include/asm-generic/percpu.h
@@@ -108,9 -118,9 +118,9 @@@ do {									
  #define this_cpu_generic_read(pcp)					\
  ({									\
  	typeof(pcp) __ret;						\
 -	preempt_disable();						\
 +	preempt_disable_notrace();					\
- 	__ret = *this_cpu_ptr(&(pcp));					\
+ 	__ret = raw_cpu_generic_read(pcp);				\
 -	preempt_enable();						\
 +	preempt_enable_notrace();					\
  	__ret;								\
  })
  

Re: linux-next: manual merge of the percpu tree with the asm-generic tree

[Arnd Bergmann]

On Tuesday 27 September 2016, Stephen Rothwell wrote:
> diff --cc include/asm-generic/percpu.h
> index 70fefec69e61,40e887068da2..000000000000
> --- a/include/asm-generic/percpu.h
> +++ b/include/asm-generic/percpu.h
> @@@ -108,9 -118,9 +118,9 @@@ do {                                                                       
>   #define this_cpu_generic_read(pcp)                                    \
>   ({                                                                    \
>         typeof(pcp) __ret;                                              \
>  -      preempt_disable();                                              \
>  +      preempt_disable_notrace();                                      \
> -       __ret = *this_cpu_ptr(&(pcp));                                  \
> +       __ret = raw_cpu_generic_read(pcp);                              \
>  -      preempt_enable();                                               \
>  +      preempt_enable_notrace();                                       \
>         __ret;                                                          \
>   })
>   

The merge solution seems correct, but this is one of only two trivial
patches I have queued up for asm-generic this time, so I wonder if we could
put the _notrace patch into the percpu tree that already has the
raw_cpu_generic_read change to avoid the conflict.

	Arnd

Re: linux-next: manual merge of the percpu tree with the asm-generic tree

[Tejun Heo]

Hello, Arnd.

On Tue, Sep 27, 2016 at 09:59:32PM +0200, Arnd Bergmann wrote:
> The merge solution seems correct, but this is one of only two trivial
> patches I have queued up for asm-generic this time, so I wonder if we could
> put the _notrace patch into the percpu tree that already has the
> raw_cpu_generic_read change to avoid the conflict.

I'll be happy to pick it up.  Can you please send me the patch
refreshed on top of percpu/for-4.9?

Thanks.

-- 
tejun