Re: [PATCH v17 08/10] PM: hibernate: disable when there are active secretmem users

From: David Hildenbrand
Date: Mon Feb 08 2021 - 08:46:33 EST


On 08.02.21 13:17, Michal Hocko wrote:
On Mon 08-02-21 12:26:31, David Hildenbrand wrote:
[...]
My F33 system happily hibernates to disk, even with an application that
succeeded in din doing an mlockall().

And it somewhat makes sense. Even my freshly-booted, idle F33 has

$ cat /proc/meminfo | grep lock
Mlocked: 4860 kB

So, stopping to hibernate with mlocked memory would essentially prohibit any
modern Linux distro to hibernate ever.

My system seems to be completely fine without mlocked memory. It would
be interesting to see who mlocks memory on your system and check whether
the expectated mlock semantic really works for those. This should be
documented at least.

I checked some other installations (Ubuntu, RHEL), and they also show no sign of Mlock. My notebook (F33) and desktop (F33) both have mlocked memory. Either related to F33 or due to some software (e.g., kerberos).

--
Thanks,

David / dhildenb