On Thu, Dec 22, 2022 at 07:38:14PM +0800, Baoquan He wrote: > On 12/21/22 at 06:44pm, Uladzislau Rezki (Sony) wrote: > > Currently __vunmap() path calls __find_vmap_area() two times. One on > > entry to check that area exists, second time inside remove_vm_area() > > function that also performs a new search of VA. > > > > In order to improvie it from a performance point of view we split > > remove_vm_area() into two new parts: > > - find_unlink_vmap_area() that does a search and unlink from tree; > > - __remove_vm_area() that does a removing but without searching. > > > > In this case there is no any functional change for remove_vm_area() > > whereas vm_remove_mappings(), where a second search happens, switches > > to the __remove_vm_area() variant where already detached VA is passed > > as a parameter, so there is no need to find it again. > > I like this patch. This takes off the va->vm clearning too. Finally I > don't need to worry about the va->flags clearing during unmapping > when reading out vmap_block areas. > Thanks. This patch was one of the reason to help out with the per-cpu busy areas tracking/reading of your work :) -- Uladzsislau Rezki
