[PVE-User] THP

[Gilberto Nunes]

Well, I enable THP indeed, there is no effect in my VM.
The only huge improvement that I really saw went when enable
cache=writeback.
No KVM is goin' high!

2016-07-15 11:48 GMT-03:00 Alexandre DERUMIER <aderumier at odiso.com>:

> >>What is big memory in this context? how many GB?
>
> default page are 4k , THP are 2MB.
>
> If you need to access 2MB memory, with 4K pages, you need to do 512calls.
> with THP only 1 call.
>
> That's why it's faster.
>
> The more memory the vm need to address , the more benefit you'll have.
> You can enable it by default if you want.
>
> The only problem with THP, is that some workload are not happy with it,
> because THP need to defragment pages sometime.
>
>
> They are also a new option in proxmox , since last month : static
> hugepages.
>
> you can add:
>
> hugepages : 2|1024
>
> to force 2mb hugepage or 1GB hugepages for this specific vm.
>
> (Note that in this case, the memory is reserved. So, no fragmentation can
> occur, but KSM is not working with this memory area)
>
>
> ----- Mail original -----
> De: "Gilberto Nunes" <gilberto.nunes32 at gmail.com>
> À: "proxmoxve" <pve-user at pve.proxmox.com>
> Envoyé: Vendredi 15 Juillet 2016 14:27:37
> Objet: Re: [PVE-User] THP
>
> Hi
>
> I think Alexandre means big huge page memory... Some databases, like SQL
> and Oracle, when have big tables, views, whatever, tend to use big page
> memory in the file system.
>
>
>
> 2016-07-15 9:22 GMT-03:00 Lindsay Mathieson <lindsay.mathieson at gmail.com>:
>
> > On 15/07/2016 9:48 PM, Alexandre DERUMIER wrote:
> >
> >> It should improve performance for vms with big memory (like database for
> >> example)
> >>
> >
> >
> >
> > What is big memory in this context? how many GB?
> >
> > --
> > Lindsay Mathieson
> >
> >
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>
>
>
> --
>
> Gilberto Ferreira
> +55 (47) 9676-7530
> Skype: gilberto.nunes36
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-- 

Gilberto Ferreira
+55 (47) 9676-7530
Skype: gilberto.nunes36