[pve-devel] proxmox6 : vhost_net experimental_zcopytx=1 bug?

[Thomas Lamprecht]

Hi,

On 8/21/19 9:31 AM, Wolfgang Bumiller wrote:
> On Tue, Aug 20, 2019 at 11:32:57AM +0200, Alexandre DERUMIER wrote:
>> Hi,
>>
>> Some users have reported vm start timeout on proxmox6
>>
>> https://forum.proxmox.com/threads/vm-doesnt-start-proxmox-6-timeout-waiting-on-systemd.56218/
>>
>> and for at least 2 of them,
>>
>> the vhost_net module option experimental_zcopytx=0 have fixed it.
> 
> I do not really see the connection, though... O.o
> Could also be an issue with our systemd related code, or with systemd's
> scope handling (yet again)...

let's really hope that that's not the case, the error seems definitively
like some other sort of issue. 

> 
>> It was enable by default since 2012, so maybe regression somewhere. (also redhat disable it by default)
>>
>>
>> It seem than in kernel 5.1, the value has been rollback to 0
>> https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v5.2.9&id=9d28094f3cf3b315e784f04ba617de8c8d8978fa 
>>
>> Not sure if this patch could be backported in proxmox 5.0 kernel ?
> 
> Makes sense IMO. After all it's an upstream decision made due to known issues.
> 

made sense to me to, so done, will only be released in the kernel after the
next one, bumped just yesterday and this went under my radar.. :/