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. > > Withtout that additional reasonaning it is not really clear why that is > needed and seems arbitrary. Would the above be a good reasoning? > > -- > Michal Hocko > SUSE Labs
