Re: [RFC 3/3] sched: depend on 64BIT_ATOMIC_ACCESS to determine if to use min_vruntime_copy

From: Peter Zijlstra
Date: Thu Aug 24 2017 - 04:49:48 EST


On Thu, Aug 24, 2017 at 02:42:57PM +0900, Hoeun Ryu wrote:
> +#ifndef CONFIG_64BIT_ATOMIC_ALIGNED_ACCESS
> u64 min_vruntime;
> -#ifndef CONFIG_64BIT
> +#else
> + u64 min_vruntime __attribute__((aligned(sizeof(u64))));
> +#endif

That's stupid, just make sure your platform defines u64 as naturally
aligned when you have this 64BIT_ATOMIC foo.

Also, please try and dig out more 32bit archs that can use this and make
sure to include performance numbers to justify this extra cruft.