Arch Linux

TheChuckster

Member

Registered: 2013-07-19

Posts: 14

StarTech USB 3.0 ExpressCard hitching issues (ACPI IRQ)

Sometimes accompanied by high kworker CPU usage

KERNEL 4.12.13-1-ARCH is affected, as well as previous versions.

Perf trace here:
https://drive.google.com/file/d/0B0wKOY … sp=sharing

I suspect it might be interrupt-related? Maybe i915? Haven't examined the trace yet though.

Last edited by TheChuckster (2017-09-25 10:29:37)

TheChuckster

Member

Registered: 2013-07-19

Posts: 14

Re: StarTech USB 3.0 ExpressCard hitching issues (ACPI IRQ)

Hm, so, it appears irq_stack_union is the culprit, but I'm struggling to get a call stack. Would really be nice to figure out what is causing all of these interrupts to get fired.

TheChuckster

Member

Registered: 2013-07-19

Posts: 14

Re: StarTech USB 3.0 ExpressCard hitching issues (ACPI IRQ)

Okay, it turns out that it is actually my StarTech USB 3.0 ExpressCard, I notice that ACPI interrupts get fired whenever it is plugged in using irqtop which is really just a nice console frontend to /proc/interrupts.

If I unplug the card, the ACPI interrupts stop getting fired (many were getting fired per second), and then my computer stops hitching.

ANNOYING