SuperMicro X11SCH - irq9: acpi0 heavy interrupts, kernel (pid 0) constant ca. 30% cpu usage

[f00b4r0]

Hi,

I'm new to FreeNAS/FreeBSD (coming from a Linux background). I have noticed that the CPU would remain under near permanent 30-36% "system" load on my fresh install of 11.2-U2.1. Digging a bit more it appears this comes from the "kernel" task (showing in top -PS).

Worried I might have done something wrong I booted a clean USB installer, started a shell and checked the output of "ps faxlr", only to notice the exact same issue, with the kernel being the second task listed and consistently using a third of the total elapsed time. MWCHAN says "swapin", STAT is "DLs".

Hardware is as follows:

• motherboard make and model: Supermicro X11SCH-LN4F
• CPU make and model: Intel Celeron G4900
• RAM quantity: 16GB ECC

Is this a known problem? Is there a fix?
The side problem is that this keeps the CPU busy and that shows on the idle power usage and average temperature...

Thanks

 

[f00b4r0]

Did a bit more investigation, it seems this usage is related to a very high rate of acpi0 interrupts:

Code:

[root@freenas /]# vmstat -i
interrupt                          total       rate
irq9: acpi0                     85001055      10059
cpu0:timer                       9518921       1126
cpu1:timer                       9518383       1126
irq264: xhci0                     396885         47
irq265: ahci0                      29897          4
irq266: igb0:que 0                312900         37
irq267: igb0:que 1                 81829         10
irq268: igb0:link                      2          0
Total                          104859872      12409

 

[f00b4r0]

OK so after a little more investigation it turns out this is indeed related to the irq storm on IRQ9 (acpi0). The same problem shows up in Linux, where the details in /proc/interrupts show that this only affects the first cpu core. So that's not a FreeNAS-specific problem.

FWIW I tried all sorts of BIOS settings to no avail, and I also checked I'm running the latest BIOS for this board.

 

[ukn]

Did you find out anything new?

I noticed the same here on a X11SCH-LN4F with i3-8100.
Latest BIOS (X11SCH8_928.zip), latest FreeNas (11.2-U2.1).

 

[Cyb3rfr3ak]

This BIOS update fixed that issue for me (Board: X11SCH-LN4F, CPU: Intel Core i3-8100).
According to Supermicro support, this release candidate can contain minor bugs.
Release date is not set but it should be in the next couple of weeks.

 

[Ericloewe]

Considering that their release versions are typically riddled with bugs inherited from AMI, that doesn't seem like a very bad thing.

 

[f00b4r0]

This BIOS update fixed that issue for me (Board: X11SCH-LN4F, CPU: Intel Core i3-8100).
According to Supermicro support, this release candidate can contain minor bugs.
Release date is not set but it should be in the next couple of weeks.

Tested, it does fix the problem here too. Thanks!

 

[Epism]

Welp, I came across your issue after looking into mine... I have the X11SCH-F, and also IRQ9/ACPI is out of control. Going to contact SM and see if they have an update I can use.

 

[Liriel]

I am looking at getting a X11SCH-F.

For folks having the IRQ storm issue, was there ever a non-release candidate BIOS update that fixed the issue? Any other issues with this MB?