Re: [PATCH V4 2/2] riscv: Use use_asid_allocator flush TLB

Christoph Hellwig
2021-05-31T06:37:03Z

On Sat, May 29, 2021 at 04:42:37PM -0700, palmerdabbelt@google.com wrote:
>>
>> Also the non-ASID code switches to a global flush once flushing more
>> than a single page. It might be worth documenting the tradeoff in the
>> code.
>
> For some reason I thought we'd written this down in the commentary of teh
> ISA manual as the suggested huersitic here, but I can't find it so maybe
> I'm wrong. If it's actually there it would be good to point that out,
> otherwise some documentation seems fine as it'll probably become a tunable
> at some point anyway.

The real question is why is the heuristic different for the ASID vs
non-ASID case? I think that really need a comment.

> LGTM. I took the first one as IMO they're really distnict issues, LMK if
> you want to re-spin this one or if I should just take what's here.

What distinct issue? The fact that the new code is buggy and uses rather
non-optimal calling conventions?