On Fri, Mar 08, 2019 at 10:22:59PM -0800, Yang Shi wrote: > Hi folks, > > > When reading the mempolicy code, I got confused by MPOL_F_MOF flag. It is > defined in include/uapi/linux/mempolicy.h, so it looks visible to the users. > But, man page doesn't mention it at all. And, the code in do_set_mempolicy() > -> mpol_new() doesn't set it. It looks it is just set by two places: > > - NUMA default policy (preferred_node_policy) > > - When MPOL_MF_LAZY is passed in. But, it is not configurable from user > since it is not valid MF > It was never exported to userspace because it was not clear how the policy would be used sensibly outside the context of the default policy. > So, actually it can't be set by user with set_mempolicy()/mbind() APIs, > right? As long as the process' or vmas' policy is changed to non-default one > (i.e. MPOL_BIND), those processes or vmas are *not* eligible for migrating > with NUMA balancing anymore? > Correct because if the policy is MPOL_BIND, it's not defined how lazy migration should behave. -- Mel Gorman SUSE Labs
