X2apic with AM5 - System Boot hangs at Early Hooks Plymouth

Operating Systems & Open Source Linux
1

Hi,

if I set the APIC mode to “x2apic” on my system, the system hangs shortly after grub at “Early Hooks Plymouth”

x2apic
x2apic1007×768 227 KB

I found this explanation, so my system meets all the requirements but the kernel is configured to run under a hypervisor, means build your own kernel or is there another solution?

if your kernel was built to support running under a hypervisor then you could very well fail

[manja-02 ~]# uname -a
Linux manja-02 6.2.16-1-MANJARO #1 SMP PREEMPT_DYNAMIC Wed May 17 17:02:01 UTC 2023 x86_64 GNU/Linux

[manja-02 ~]# zgrep CONFIG_X86_X2APIC /proc/config.gz
CONFIG_X86_X2APIC=y

[manja-02 ~]# zgrep CONFIG_IRQ_REMAP /proc/config.gz
CONFIG_IRQ_REMAP=y


[manja-02 ~]# journalctl -b | grep -i "irq rem"
Mai 26 21:30:20 manja-02 kernel: x2apic: IRQ remapping doesn't support X2APIC mode
2

Sorry for raising the dead, but did you ever find a solution for this? I have the same issue with a 7950x3d and 2 B650 boards, an ASrock and Gigabyte.

3

No, I didn’t try it again because my system works well, I was just curious if it had any measurable benefits.
If I understood the topic correctly, x2apic only really has advantages on large systems with many VMs

1 Like
4

That’s my understanding also, from searching around.

I emailed ASRock support about the issue a few days ago, but haven’t received a response yet. I’ll send an update if they ever get back to me.