On Sat, Jan 30, 2021 at 4:16 PM Nadav Amit [off-list ref] wrote:

From: Nadav Amit <redacted>

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?