On Tue, Apr 02, 2024 at 12:06:56AM -0400, Yu Zhao wrote: > On Mon, Apr 1, 2024 at 7:30 PM James Houghton <jthoughton@xxxxxxxxxx> wrote: > > Suggested-by: Yu Zhao <yuzhao@xxxxxxxxxx> > > Thanks but I did not suggest this. Entirely up to you, but I would still want to credit everyone who contributed to a feature even if the underlying implementation has changed since the original attempt. > What I have in v2 is RCU based. I hope Oliver or someone else can help > make that work. Why? If there's data to show that RCU has a material benefit over taking the MMU lock for read then I'm all for it. Otherwise, the work required to support page-table walkers entirely outside of the MMU lock isn't justified. In addition to ensuring that page table teardown is always RCU-safe, we'd need to make sure all of the walkers that take the write lock are prepared to handle races. > Otherwise we can just drop this for now and revisit > later. I really wouldn't get hung up on the locking as the make-or-break for whether arm64 supports this MMU notifier. -- Thanks, Oliver
