Hi!
My system has 64G of ram and I want to create 32 1G huge pages to use
in KVM virtualization,
on demand, only when VM is running.
So I booted the kernel with
'hugepagesz=1G hugepages=0 default_hugepagesz=1G movablecore=40G'
However I still can't allocate the pages reliably.
For instance this simple script is enough to make it not possible to
even allocate one 1G huge page after few dozens of iterations:
while true ; do
sudo hugeadm --enable-zone-movable --pool-pages-min 1G:0G
sudo hugeadm --enable-zone-movable --pool-pages-min 1G:60G
done
I disabled mlock systemwide (now ulimit -l shows 0), I still see 8
pages mlocked in zone 'Movable' but this is not enough to explain
this
nr_mlock 8
I do have around 64GB of swap too, but I see no even an attempt to use it.
# free
total used free shared buff/cache available
Mem: 65887928 1748344 62640276 61688 1499308 62053832
Swap: 67108860 0 67108860
Any idea about what is going on?
This was tested on 4.14.0-rc5 (my custom compiled) and on several
older kernels (4.10,4.12,4.13) from ubuntu repositories.
Disabling/enabling transparent huge pages in the kernel config didn't
make a difference.
VT-d was enabled during the tests (intel_iommu=on,igfx_off) if that
would make any difference, but no VM was started when I run the above
script, in fact I run it just after the system booted.
Best regards,
Maxim Levitsky
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