[RFC 00/20] TLB batching consolidation and enhancements

[Nadav Amit]

> On Jan 30, 2021, at 4:39 PM, Andy Lutomirski <luto at kernel.org> wrote:
> 
> On Sat, Jan 30, 2021 at 4:16 PM Nadav Amit <nadav.amit at gmail.com> wrote:
>> From: Nadav Amit <namit at 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?

Yes.