Re: [pve-devel] [RFC kernel] revert problematic TSC multiplier commit

[Fiona Ebner <f.ebner@proxmox.com>]

Hi,

Am 02.09.22 um 09:22 schrieb Eneko Lacunza:
> Hi Fiona,
> 
> Does this patch correspond to kernels linked in this forum thread?
> 
> https://forum.proxmox.com/threads/proxmox-7-2-3-ceph-16-2-7-migrating-vms-hangs-them-kernel-panic-on-linux-freeze-on-windows.109645/page-2#post-488479
> 

No, there is no public build with the below patch yet.

Did you already test the kernel with the fpu patches that's mentioned in
that forum post?

> 
> If so I can test them and see if that helps with bugzilla entry #4073:
> https://bugzilla.proxmox.com/show_bug.cgi?id=4073
> 

I don't think theses issues are related, as there, the VM that's been
migrated hangs, and here other VMs on the node were affected.

> Thanks
> 
> El 1/9/22 a las 8:25, Fiona Ebner escribió:
>> Am 31.08.22 um 15:28 schrieb Fiona Ebner:
>>> which might be responsible for several issues reported in the
>>> community forum[0][1].
>>>
>>> In my case, loading a VM snapshot that originally was taken on
>>> a CPU from a different vendor often caused problems in other VMs(!).
>>> In particular, it often led to RCU stalls (with similar messages as in
>>> [1]) or slowdowns, and sometimes clock jumps far into the future (like
>>> in [0]). With this revert applied, everything seems to run smoothly
>>> even after loading the "bad" snapshot 10 times.
>>>
>>> [0]https://forum.proxmox.com/threads/112756/
>>> [1]https://forum.proxmox.com/threads/111494/

The fix 11d39e8cc43e1c6737af19ca9372e590061b5ad2 is only for AMD/SVM, so
most likely [1], where people with Intel N5105 are affected, is not
related either. RCU stall messages can happen for different reasons of
course ;)