On Wed, Jan 18, 2023 at 1:33 PM Michal Hocko <mhocko@xxxxxxxx> wrote: > > On Wed 18-01-23 10:09:29, Suren Baghdasaryan wrote: > > On Wed, Jan 18, 2023 at 1:23 AM Michal Hocko <mhocko@xxxxxxxx> wrote: > > > > > > On Tue 17-01-23 18:01:01, Suren Baghdasaryan wrote: > > > > On Tue, Jan 17, 2023 at 7:16 AM Michal Hocko <mhocko@xxxxxxxx> wrote: > > > > > > > > > > On Mon 09-01-23 12:53:12, Suren Baghdasaryan wrote: > > > > > > Move VMA flag modification (which now implies VMA locking) before > > > > > > anon_vma_lock_write to match the locking order of page fault handler. > > > > > > > > > > Does this changelog assumes per vma locking in the #PF? > > > > > > > > Hmm, you are right. Page fault handlers do not use per-vma locks yet > > > > but the changelog already talks about that. Maybe I should change it > > > > to simply: > > > > ``` > > > > Move VMA flag modification (which now implies VMA locking) before > > > > vma_adjust_trans_huge() to ensure the modifications are done after VMA > > > > has been locked. > > > > > > Because .... > > > > because vma_adjust_trans_huge() modifies the VMA and such > > modifications should be done under VMA write-lock protection. > > So it will become: > Move VMA flag modification (which now implies VMA locking) before > vma_adjust_trans_huge() to ensure the modifications are done after VMA > has been locked. Because vma_adjust_trans_huge() modifies the VMA and such > modifications should be done under VMA write-lock protection. > > which is effectivelly saying > vma_adjust_trans_huge() modifies the VMA and such modifications should > be done under VMA write-lock protection so move VMA flag modifications > before so all of them are covered by the same write protection. > > right? Yes, and the wording in the latter version is simpler to understand IMO, so I would like to adopt it. Do you agree? > -- > Michal Hocko > SUSE Labs
