Re: [RFC 00/20] TLB batching consolidation and enhancements

Andy Lutomirski
2021-01-31T00:41:13Z

On Sat, Jan 30, 2021 at 4:16 PM Nadav Amit <nadav.amit@gmail.com> wrote:
>
> From: Nadav Amit <namit@vmware.com>
>
> There are currently (at least?) 5 different TLB batching schemes in the
> kernel:
>
> 1. Using mmu_gather (e.g., zap_page_range()).
>
> 2. Using {inc|dec}_tlb_flush_pending() to inform other threads on the
> ongoing deferred TLB flush and flushing the entire range eventually
> (e.g., change_protection_range()).
>
> 3. arch_{enter|leave}_lazy_mmu_mode() for sparc and powerpc (and Xen?).
>
> 4. Batching per-table flushes (move_ptes()).
>
> 5. By setting a flag on that a deferred TLB flush operation takes place,
> flushing when (try_to_unmap_one() on x86).

Are you referring to the arch_tlbbatch_add_mm/flush mechanism?