Re: [PATCH] RISC-V: Issue a local tlb flush if possible.

From: hch@xxxxxxxxxxxxx
Date: Mon Aug 19 2019 - 11:10:26 EST

On Mon, Aug 19, 2019 at 08:39:02PM +0530, Anup Patel wrote:
> If we were using ASID then yes we don't need to flush anything
> but currently we don't use ASID due to lack of HW support and
> HW can certainly do speculatively page table walks so flushing
> local TLB when MM mask is empty might help.
> This just my theory and we need to stress test more.

Well, when we context switch away from a mm we always flush the
local tlb. So either the mm_struct has never been scheduled in,
or we alrady did a local_tlb_flush and we context switched it up.