On Thu, 21 Oct 2021 05:21:07 -0700 Nadav Amit <nadav.amit@xxxxxxxxx> wrote: > This patch-set is intended to remove unnecessary TLB flushes. It is > based on feedback from v1 and several bugs I found in v1 myself. > > Basically, there are 3 optimizations in this patch-set: > 1. Avoiding TLB flushes on change_huge_pmd() that are only needed to > prevent the A/D bits from changing. > 2. Use TLB batching infrastructure to batch flushes across VMAs and > do better/fewer flushes. > 3. Avoid TLB flushes on permission demotion. > > Andrea asked for the aforementioned (2) to come after (3), but this > is not simple (specifically since change_prot_numa() needs the number > of pages affected). [1/5] appears to be a significant fix which should probably be backported into -stable kernels. If you agree with this then I suggest it be prepared as a standalone patch, separate from the other four patches. With a cc:stable. And the remaining patches are a performance optimization. Has any attempt been made to quantify the benefits?
