> On Tue, Dec 03, 2024 at 08:02:26PM +0100, Uladzislau Rezki wrote: > > I think there are a few other things we can try here. > > First, if the copy is small (and I still don't have an answer to that > ...), we can skip the vmalloc lookup if the copy doesn't cross a page > boundary. > I noticed that, a path which is in question, does not supply a starting address of mapping area, instead it passes something within.
> > Second, we could try storing this in a maple tree rather than an rbtree. > That gives us RCU protected lookups rather than under a spinlock. > I think, when i have more free cycles, i will check it from performance point of view. Because i do not know how much a maple tree is efficient when it comes to lookups, insert and removing. As an RCU safe data structure, yes, a searching is improved in a way there is no need in taking spinlock. As a noted earlier i do not know if a maple tree allows to find a data when instead of key, it is associated with, we pass something that is withing a searchable area: [va_start:va_end]. -- Uladzislau Rezki
