Re: [PATCH v2 00/28] The new cgroup slab memory controller

From: David Hildenbrand
Date: Thu Sep 03 2020 - 14:09:25 EST


> For performance reasons during system updates/reboots we do not erase
> memory content. The memory content is erased only on power cycle,
> which we do not do in production.
>
> Once we hot-remove the memory, we convert it back into DAXFS PMEM
> device, format it into EXT4, mount it as DAX file system, and allow
> programs to serialize their states to it so they can read it back
> after the reboot.
>
> During startup we mount pmem, programs read the state back, and after
> that we hotplug the PMEM DAX as a movable zone. This way during normal
> runtime we have 8G available to programs.
>

Thanks for sharing the workflow - while it sounds somewhat sub-optimal,
I guess it gets the job done using existing tools / mechanisms.

(I remember the persistent tmpfs over kexec RFC, which tries to tackle
it by introducing something new)

--
Thanks,

David / dhildenb