On Tue, 8 Oct 2019, Leonardo Bras wrote: > > You are creating contention on a single exclusive cacheline. Doesnt this > > defeat the whole purpose of the lockless page table walk? Use mmap_sem or > > so should cause the same performance regression? > > Sorry, I did not understand that question. > I mean, this is just a refcount and never causes a lock. Locks also use atomic operations like a refcount increment. Both require the cacheline to be in exclusive state. So the impact is very similar.
