On Thu 26-12-19 14:02:04, Luigi Semenzato wrote: [...] > +Limitations of Hibernation > +========================== > + > +When entering hibernation, the kernel tries to allocate a chunk of memory large > +enough to contain a copy of all pages in use, to use it for the system > +snapshot. If the allocation fails, the system cannot hibernate and the > +operation fails with ENOMEM. This will happen, for instance, when the total > +amount of anonymous pages (process data) exceeds 1/2 of total RAM. > + > +One possible workaround (besides terminating enough processes) is to force > +excess anonymous pages out to swap before hibernating. This can be achieved > +with memcgroups, by lowering memory usage limits with ``echo <new limit> > > +/dev/cgroup/memory/<group>/memory.mem.usage_in_bytes``. However, the latter > +operation is not guaranteed to succeed. I am not familiar with the hibernation process much. But what prevents those allocations to reclaim memory and push out the anonymous memory to the swap on demand during the hibernation's allocations? -- Michal Hocko SUSE Labs
