Re: [PATCH v2 2/3] x86/mm: Make flush_tlb_mm_range() more predictable

From: Dave Hansen
Date: Fri Apr 21 2017 - 14:54:23 EST


On 04/21/2017 11:15 AM, Andy Lutomirski wrote:
> I'm about to rewrite the function almost completely, but first I
> want to get a functional change out of the way. Currently, if
> flush_tlb_mm_range() does not flush the local TLB at all, it will
> never do individual page flushes on remote CPUs. This seems to be
> an accident, and preserving it will be awkward. Let's change it
> first so that any regressions in the rewrite will be easier to
> bisect and so that the rewrite can attempt to change no visible
> behavior at all.
>
> The fix is simple: we can simply avoid short-circuiting the
> calculation of base_pages_to_flush.

This looks sane to me. I think it makes things more straightforward.

Acked-by: Dave Hansen <dave.hansen@xxxxxxxxx>