Re: [PATCH v2 00/10] x86: Clean up percpu operations

[Peter Zijlstra]

On Sat, May 30, 2020 at 06:11:17PM -0400, Brian Gerst wrote:
> The core percpu operations already have a switch on the width of the
> data type, which resulted in an extra amount of dead code being
> generated with the x86 operations having another switch.  This patch set
> rewrites the x86 ops to remove the switch.  Additional cleanups are to
> use named assembly operands, and to cast variables to the width used in
> the assembly to make Clang happy.
> 
> Changes from v1:
> - Add separate patch for XADD constraint fix
> - Fixed sparse truncation warning
> - Add cleanup of percpu_stable_op()
> - Add patch to Remove PER_CPU()
> 
> Brian Gerst (10):
>   x86/percpu: Introduce size abstraction macros
>   x86/percpu: Clean up percpu_to_op()
>   x86/percpu: Clean up percpu_from_op()
>   x86/percpu: Clean up percpu_add_op()
>   x86/percpu: Remove "e" constraint from XADD
>   x86/percpu: Clean up percpu_add_return_op()
>   x86/percpu: Clean up percpu_xchg_op()
>   x86/percpu: Clean up percpu_cmpxchg_op()
>   x86/percpu: Clean up percpu_stable_op()
>   x86/percpu: Remove unused PER_CPU() macro
> 
>  arch/x86/include/asm/percpu.h | 510 ++++++++++++----------------------
>  1 file changed, 172 insertions(+), 338 deletions(-)

Nice!

Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>