Re: [PATCH 3/3] IPI: Avoid to use 2 cache lines for one call_single_data

[Peter Zijlstra]

On Wed, Aug 02, 2017 at 03:18:58AM -0700, Eric Dumazet wrote:
> What we can do instead is to force an alignment on 4*sizeof(void *).
> (32 bytes on 64bit, 16 bytes on 32bit arches)
> 
> Maybe something like this :
> 
> diff --git a/include/linux/smp.h b/include/linux/smp.h
> index 68123c1fe54918c051292eb5ba3427df09f31c2f..f7072bf173c5456e38e958d6af85a4793bced96e 100644
> --- a/include/linux/smp.h
> +++ b/include/linux/smp.h
> @@ -19,7 +19,7 @@ struct call_single_data {
>  	smp_call_func_t func;
>  	void *info;
>  	unsigned int flags;
> -};
> +} __attribute__((aligned(4 * sizeof(void *))));

Agreed.