Re: [Qemu-devel] >256 Virtio-net-pci hotplug Devices

[Kinsella, Ray]

Hi Marcel,

On 24/07/2017 00:14, Marcel Apfelbaum wrote:
> On 24/07/2017 7:53, Kinsella, Ray wrote:
>
> Even if I am not aware of how much time would take to init a bare-metal
> PCIe Root Port, it seems too much.

So I repeated the testing for 64, 128, 256 and 512 ports. I ensured the 
configuration was sane, that 128 was twice the number of root ports and 
virtio-pci-net devices as 64.

I got the following results - shown in seconds, as you can see it is non 
linear but not exponential, there is something that is not scaling well.

                64      128     256     512
PCIe Root Ports 14      72      430     2672
ACPI            4       35      342     3863
Loading Drivers 1       1       31      621
Total Boot      34      137     890     7516

( I did try to test 1024 devices, but it just dies silently )

Ray K