Comment 62 for bug 159356

Hi to the new updaters, :-)

I found this to happen with several instances of chrome, or with file operations over big files in combination. I've filed a bug report that was confirmed a couple of years ago:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1504914

One thing that helped me to avoid some hang if I manage to do it promptly was to go su and use the drop_caches

$ sudo su
$ free -h && sync && echo 3 > /proc/sys/vm/drop_caches && free -h

But this works temporarily and as long as I don't keep with many instances or big files accesses.
HTH

PS:
Ubuntu 16.04.03, encrypted home, 16GB RAM, 16Gb swap file. Default swapiness, cache_pressure and min_free_kbytes
uname -a
Linux big 4.4.0-96-generic #119-Ubuntu SMP Tue Sep 12 14:59:54 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux