On Tue, 11 Feb 2020, Mina Almasry wrote: > An earlier patch in this series disabled file_region coalescing in order > to hang the hugetlb_cgroup uncharge info on the file_region entries. > > This patch re-adds support for coalescing of file_region entries. > Essentially everytime we add an entry, we call a recursive function that > tries to coalesce the added region with the regions next to it. The > worst case call depth for this function is 3: one to coalesce with the > region next to it, one to coalesce to the region prev, and one to reach > the base case. > > This is an important performance optimization as private mappings add > their entries page by page, and we could incur big performance costs for > large mappings with lots of file_region entries in their resv_map. > > Signed-off-by: Mina Almasry <almasrymina@xxxxxxxxxx> Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
