On Mon 14-08-23 09:59:51, Huang, Ying wrote: > Hi, Michal, > > Michal Hocko <mhocko@xxxxxxxx> writes: > > > On Fri 11-08-23 17:08:19, Huang Ying wrote: > >> If there is no memory allocation/freeing in the remote pageset after > >> some time (3 seconds for now), the remote pageset will be drained to > >> avoid memory wastage. > >> > >> But in the current implementation, vmstat updater worker may not be > >> re-queued when we are waiting for the timeout (pcp->expire != 0) if > >> there are no vmstat changes, for example, when CPU goes idle. > > > > Why is that a problem? > > The pages of the remote zone may be kept in the local per-CPU pageset > for long time as long as there's no page allocation/freeing on the > logical CPU. In addition to the logical CPU goes idle, this is also > possible if the logical CPU is busy in the user space. But why is this a problem? Is the scale of the problem sufficient to trigger out of memory situations or be otherwise harmful? -- Michal Hocko SUSE Labs
