On Thu, Apr 27, 2023 at 3:33 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > - Suren Baghdasaryan has improved mmap_lock scalability by switching to > per-VMA locking. .. related to this, we have that new PER_VMA_LOCK_STATS config entry, which is 'default y' and has basically no help test. Please don't do that. I don't think any of the VM debugging stuff should likely be 'default y' in the first place, but if they are, they should most definitely have a good *explanation* for why they should be on for a normal user. Linus