Slow boot on rocky linux 10 latest kernel

henri9813

Hello,

When i boot a Rocky Linux 10 with the latest kernel, it's very slow on cpu XXX spinlock event irq.

Someone have the same issue ?

Thanks !

poddingue

I'm not familiar with the Rocky 10 kernel internals, but a spinlock storm on a vCPU during boot often comes from how the guest kernel handles its paravirtual clock/timer with the host, rather than anything Rocky-specific.
Could you share your XCP-ng version, and whether an older RL10 kernel (or an RL9 one) boots normally on the same VM? That would tell us if it's genuinely the latest kernel that regressed.
If it only happens on that kernel and it's hard to test elsewhere, a mention to @Team-Hypervisor-Kernel might help, since they can check whether it reproduces on their side.

dinhngtu

@poddingue FWIW I've seen the same on FC44 as well, but I don't yet know where it came from.

TeddyAstie

Can reproduce on Fedora 44 and Alpine Linux (6.18.22-0-virt).
But doesn't occur on Debian 13 (6.12).

acebmxer

@TeddyAstie

From Debian 13 cloud inti. Does on every reboot from fresh image.

added more vcpus.

TeddyAstie

@acebmxer which kernel version you have in your Debian guest (uname -a) ?

acebmxer

@TeddyAstie

This is on fresh install Debian 13 deployed from XO Hub - 6.12.38+deb13-amd64. I do not see this behavior on Ubuntu.

after update 6.12.90+deb13.1-amd64
still happens.

TeddyAstie

@acebmxer I don't observe the same issue on Debian 13 Cloud-Init (both 6.12.38+deb13-amd64 and updated 6.12.90+deb13.1-amd64).

Though it still takes some time to boot (especially at loading the ramdisk) but it's not related to this pv spinlock issue and mostly a "BIOS guest" related issue.
But I'm testing on a Intel machine.

henri9813

Hello,

To gave more details abouit my case:

XCPNG: 8.3.0
CPU: AMD EPYC 4464P 12-Core Processor
Kernel: 6.12.0-211.18.1.el10_2.x86_64

acebmxer

I was going to suggest it might be a amd issue. I can try later on work host that are intel.