It seems that is an issue on 5.10.xxx kernels, but no longer the case
for the 5.15.
On Wed, Nov 23, 2022 at 10:39 AM Ivan Volosyuk wrote:
>
> I'm highly confident that I use preallocated hugetlb pages and I have
> most of ram free on 64GB system. The problem appears only with:
> CONFIG_PREEMPT=y
I'm highly confident that I use preallocated hugetlb pages and I have
most of ram free on 64GB system. The problem appears only with:
CONFIG_PREEMPT=y
$ cat /proc/sys/vm/nr_hugepages
8192
$ cat /proc/meminfo
..
HugePages_Total:8192
HugePages_Free:0
$ mount |grep huge
hugetlbfs on
On Tue, 22 Nov 2022 12:35:56 -1000
Bryan Angelo wrote:
> Related follow up.
>
> When I add memory to a running VM via hotplug, QEMU preallocates this
> memory too (as expected based on your explanation). When I subsequently
> remove memory added to the VM via hotplug, QEMU does not always
Related follow up.
When I add memory to a running VM via hotplug, QEMU preallocates this
memory too (as expected based on your explanation). When I subsequently
remove memory added to the VM via hotplug, QEMU does not always appear to
free the underlying memory.
For example:
-m
On Tue, 22 Nov 2022 17:57:37 +1100
Ivan Volosyuk wrote:
> Is there something special about the pinning step? When I start a new
> VM with 16G in dedicated hugepages my system becomes quite
> unresponsive for several seconds, significant packet loss and random
> hang device oopses if I use
Is there something special about the pinning step? When I start a new
VM with 16G in dedicated hugepages my system becomes quite
unresponsive for several seconds, significant packet loss and random
hang device oopses if I use preemptive kernel?
On Mon, Nov 21, 2022 at 12:54 PM Alex Williamson
Thanks for the clear explanation and detail.
On Sun, Nov 20, 2022, 17:54 Alex Williamson
wrote:
> On Sun, 20 Nov 2022 16:36:58 -0800
> Bryan Angelo wrote:
>
> > When passing-through via vfio-pci using QEMU 7.1.0 and OVMF, it appears
> > that qemu preallocates all guest system memory.
> >
> >
On Sun, 20 Nov 2022 16:36:58 -0800
Bryan Angelo wrote:
> When passing-through via vfio-pci using QEMU 7.1.0 and OVMF, it appears
> that qemu preallocates all guest system memory.
>
> qemu-system-x86_64 \
> -no-user-config \
> -nodefaults \
> -nographic \
> -rtc base=utc \
>
When passing-through via vfio-pci using QEMU 7.1.0 and OVMF, it appears
that qemu preallocates all guest system memory.
qemu-system-x86_64 \
-no-user-config \
-nodefaults \
-nographic \
-rtc base=utc \
-boot strict=on \
-machine pc,accel=kvm,dump-guest-core=off \
-cpu
