lazy-tlb-allow-lazy-tlb-mm-refcounting-to-be-configurable-fix-2

lazy-tlb-allow-lazy-tlb-mm-refcounting-to-be-configurable-fix-2

Explain the requirements for lazy tlb mm refcounting in the comment,
to help with archs that may want to disable this by some means other
than MMU_LAZY_TLB_SHOOTDOWN.

Link: https://lkml.kernel.org/r/1623121605.j47gdpccep.astroid@bobo.none
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>