[vfio-users] VM slows down with +2gb RAM

Tue Oct 20 09:29:52 UTC 2015

Hi,

Nice to see that I was right. That was coming from the mailing list, time ago, so if you recently joined, you can probably see that in the archive.

Also I feel free to follow Alex suggestion, I think hugepages surely help.

Best regards.

José 

-----Original Message-----
From: "Manuel Zeusin" <zeusin360 at gmail.com>
Sent: ‎20/‎10/‎2015 04:06
To: "José Ramón Muñoz" <koalinux at gmail.com>
Cc: "vfio-users at redhat.com" <vfio-users at redhat.com>; "alex.willianson at redhat.com" <alex.willianson at redhat.com>
Subject: Re: [vfio-users] VM slows down with +2gb RAM

First, Thank you for take your time to respond my questions,

José, you remember veeery good, qemu 2.3.1 + fedora 22 with 4.0.4 kernel can assign more ram than 2gb. I going to sleep this night with a happy face, thanks to you :D. i like to know in which fórum you read that, if it's posible.

Alex, I going to try to use hugepages, because very often i have micro stuttering, for example in games... to describe the errors ocurred with 4.2 kernel, the host itself it's idle with lxde and no applications open, just qemu loads with 100% cpu usage for cpus assignement to VM and the same for RAM, in this case, more tan 4gb free.

For the first PD, is there any way to remove the host gpu? for me it's useless and if i can remove it i'm goint to sell this shitty gigabyte and buy a asrock... ( with asrock can't change the priority of vga pcie to boot, so i waste a pcie 3.0 x16 to radeon 2600hd, but iommu in xen/VMWare Works well and gigabyte can change the vga pcie boot priority, so i can use pcie 3.0 x16 to nvidia 970 and host gpu radeon hd2600 is in pcie 2.0 x4, but its totally incompatible with xen/VMWare... just boot with one core -.-')

Thank you so MUCH for you time.

2015-10-19 19:23 GMT+02:00 José Ramón Muñoz <koalinux at gmail.com>:

        Hi,

        Which versions of qemu and kernel are you using? I remember to have read
some similar cpu hangs out in recent kernels with recent qemu versions. If I'm
right it should be enough to lower the kernel to 4.1.x.

        Best regards.

        José.

On Monday 19 October 2015 13:01:53 Manuel Zeusin wrote:
> Hello,
>
> I try to make a multi-os gaming machine, one win 10 with NVIDIA 970 and
> other with win10 and AMD 7770... I can do it work and works like a
> charm...but with 2gb...
>
> My host is a 5820k with 4*4gb RAM, gigabyte X99-ud4 ( a shitty mobo ),
> radeon 2600hd for host, NVIDIA 970 and radeon 7770.
>
> For example, i do a fresh installation of windows for NVIDIA, with 2gb RAM.
> The installation complete and GPU have vídeo, shutdown the computer and
> assign 4gb, Windows boot and everything slows down at almost freeze and CPU
> goes to 80-100% with no reason, it doesnt matter if have 1vcpu or 10vcpu.
> gpu sometimes have vídeo and sometimes not...  But.... If i remove VGA PCI
> assignement, windows boot fine and works like a charm.
>
> I try fedora 22 and debian testing with the same result.
>
> PD: there is any possibilty to remove the radeon 2600 GPU host and do the
> same with 2 GPU? I know with unraid distro its possible, but i cant do it
> with debian.
>
> PD2: bad english, i know. Spanish here.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/vfio-users/attachments/20151020/760bfc16/attachment.htm>