[pve-devel] [PATCH] add hugepages option v5

[Alexandre DERUMIER]

> I can add an error like "1GB hugepages are not compatible with memory hotplug currently" if you want.

>>What if we then start with a $dimm_size of 1G?
>>At least qemu seems happy with it then? Or is there downside to this?

Yes, we can do that. 
But only when 1GB hugepages are enabled is this case ? (to not break migration of current vm with memory hotplug enable)


----- Mail original -----
De: "Wolfgang Bumiller" <w.bumiller at proxmox.com>
À: "aderumier" <aderumier at odiso.com>, "pve-devel" <pve-devel at pve.proxmox.com>
Envoyé: Mercredi 8 Juin 2016 08:27:08
Objet: Re: [pve-devel] [PATCH] add hugepages option v5

> On June 8, 2016 at 5:40 AM Alexandre DERUMIER <aderumier at odiso.com> wrote: 
> 
> 
> >>When not specifying numaX entries we run into this code using the 
> >>default $dimm_size of 512, which won't work with 1G pages. Iow this 
> >>config without any `numa0`, `numa1`, ... entries: 
> >> hugepages: 1024 
> >> numa: 1 
> >>will error at this point about wrong memory sizes. We could probably 
> >>catch this in foreach_dimm()? 
> 
> About this, this is only when memory hotplug is enabled. 
> It's will not work with 1GB currently, because indeed, we start with 512MB dimm_size. 
> 
> The check is already done in foreach_dimm -> print_mem_object -> hugepages_size 
> 
> 
> I can add an error like "1GB hugepages are not compatible with memory hotplug currently" if you want. 

What if we then start with a $dimm_size of 1G? 
At least qemu seems happy with it then? Or is there downside to this?