[pve-devel] qemu memory hotplug limited to 64 dimm

[Alexandre DERUMIER]

>>Why is that patch not applied to upstream? Maybe we can ask on the kernel list?

>From what I have read, they are an performance impact with more than 64 dimm,
and until they have fixed it, they don't want to increase value

https://patchwork.kernel.org/patch/5825741/
"I'm almost done with approach suggested by Paolo,
i.e. replace linear search with faster/scalable lookup alg.
Hope to post it soon.
"

We can simply add a file:
/etc/modprobe.d/vhost.conf 
   options vhost max_mem_regions=509


But, as Wolfgang, I also think that be able to define optional fixed dimm size could be great too.

----- Mail original -----
De: "dietmar" <dietmar at proxmox.com>
À: "Wolfgang Bumiller" <w.bumiller at proxmox.com>
Cc: "aderumier" <aderumier at odiso.com>, "pve-devel" <pve-devel at pve.proxmox.com>
Envoyé: Mardi 13 Décembre 2016 16:37:41
Objet: Re: [pve-devel] qemu memory hotplug limited to 64 dimm

> > Any drawbacks? 
> 
> It's a hack... I find the idea of configuring the dimm size more 
> appealing. Why would you want a huge amount of tiny DIMMs in a VM, 

Because it works out of the box (for the users) ... 

> especially if it means kernel-patching... ? :| 

Why is that patch not applied to upstream? Maybe we can ask on the kernel list?