I am getting Out of Memory errors while my swap isn't touched.  I have 4GB of ram and 4GB of swap space.  I enabled the swap via swapon and when doing free, I see the swap listed there.I'm thinking that perhaps there is some issue with overlayfs / tmpfs and swap all working together.  I have always had the opposite problem, trying to prevent swap usage, so I can't seem to figure out what changed.Also, I am using a grsecurity enabled kernel.  Is it possible that memory allocation work differently under there?Snapshot of free:                      total        used        free      shared  buff/cache   available          Mem:        3586392      157292       67052      141664     3362048     3236524          Swap:       4194300           0     4194300After I added the swap configuration to /etc/fstab, these numbers have changed; however, I still don't see any swap usage.  The only other thing I changed was the tmpfs size for /dev/shm and my overlayfs volume (/rw).  Both of which were not using much space to begin with, so the change should not have had any impact.                      total        used        free      shared  buff/cache   available          Mem:        3586392      571392     1714036      146096     1300964     2818004          Swap:       4194300           0     4194300I restarted a bunch of services and they're still running, and the biggest difference I see is that free memory is now showing 1.7GB free versus 67MB prior.I'm still confused as to why that had any impact.  If I enable swap through swapon, it should behave the same way as if I configure it through /etc/fstab and do swapon -a.  Furthermore, it isn't even being used yet anyways.
linux - OOM / swap not being used
linux;swap;overlayfs
This was a bug with the version of the kernel I was using.