Re: [PATCH 3/4] mm/tlb, x86/mm: Support invalidating TLB caches for RCU_TABLE_FREE

From: Linus Torvalds
Date: Wed Aug 22 2018 - 17:34:42 EST


On Wed, Aug 22, 2018 at 8:46 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -180,6 +180,7 @@ config X86
> select HAVE_PERF_REGS
> select HAVE_PERF_USER_STACK_DUMP
> select HAVE_RCU_TABLE_FREE
> + select HAVE_RCU_TABLE_INVALIDATE if HAVE_RCU_TABLE_FREE

This is confusing. First you select HAVE_RCU_TABLE_FREE
unconditionally, and then you select HAVE_RCU_TABLE_INVALIDATE based
on that unconditional variable.

I can see why you do it, but that's because I see the next patch. On
its own it just looks like you have a drinking problem.

That said, I was waiting to see if this patch-set would get any
comments before applying it, but it's been mostly crickets... So I
think I'll just apply it and get this issue over and done with.

Linus