> On Feb 1, 2021, at 10:41 PM, Nicholas Piggin <npiggin@xxxxxxxxx> wrote: > > Excerpts from Peter Zijlstra's message of February 1, 2021 10:09 pm: >> I also don't think AGRESSIVE_FLUSH_BATCHING quite captures what it does. >> How about: >> >> CONFIG_MMU_GATHER_NO_PER_VMA_FLUSH > > Yes please, have to have descriptive names. Point taken. I will fix it. > > I didn't quite see why this was much of an improvement though. Maybe > follow up patches take advantage of it? I didn't see how they all fit > together. They do, but I realized as I said in other emails that I have a serious bug in the deferred invalidation scheme. Having said that, I think there is an advantage of having an explicit config option instead of relying on whether tlb_end_vma is defined. For instance, Arm does not define tlb_end_vma, and consequently it flushes the TLB after each VMA. I suspect it is not intentional.
