Hi, sorry for the late reply. On Fri, Oct 29, 2021 at 4:37 PM Mel Gorman <mgorman@xxxxxxx> wrote: > > My point is that as it stands, > prctl(PR_NUMA_BALANCING,PR_SET_NUMA_BALANCING,1) either does nothing or > fails. If per-process numa balancing is to be introduced, it should have > meaning with the global tuning affecting default behaviour and the prctl > affecting specific behaviour. > If the global tuning affects default behaviour and the prctl affects specific behaviour. Then when prctl specifies numa_balancing for a process, there is no way for the global tuning to affect that process. In other words, global tuning become a default value, not a switch for global numa_balancing. My idea is that the global numa_balancning still has absolute control, and prctl can only optionally turn off numa_balancing for process when the global is on. After all, It is more common to enable global numa_balancing and disable it in several processes than to disable global numa_balancing and enable it in several processes. This is my personal opinion, what do you think. :-) Do we need the global to be a switch, or a default value?