On Mon 13-11-17 09:28:33, Minchan Kim wrote: [...] > Thanks for the patch, Michal. > However, it would be nice to do it tranparently without asking > new flags from users. > > When I read tlb_gather_mmu's description, fullmm is supposed to > be used only if there is no users and full address space. > > That means we can do it API itself like this? > > void arch_tlb_gather_mmu(...) > > tlb->fullmm = !(start | (end + 1)) && atomic_read(&mm->mm_users) == 0;
I do not have a strong opinion here. The optimization is quite subtle so calling it explicitly sounds like a less surprising behavior to me longterm. Note that I haven't checked all fullmm users. -- Michal Hocko SUSE Labs
