Subject: Re: 'do_IRQ: stack overflow: 1072' at using bcachefs partition (ppc32, kernel 6.10.5)

From: Michael Ellerman <[email-masked]>
Date: Fri, 16 Aug 2024 21:55:46 +1000

Erhard Furtner <[email-masked]> writes:
> Greetings!
>
> Basically bcachefs works on ppc32 but I get stack overflows like this one rather easy:
>
> [...]
> do_IRQ: stack overflow: 1072
> CPU: 1 PID: 2114 Comm: bash Not tainted 6.10.5-gentoo-PMacG4 #1
> Hardware name: PowerMac3,6 7455 0x80010303 PowerMac
> Call Trace:
> [effe3fc0] [c0785664] dump_stack_lvl+0x70/0x8c (unreliable)
> [effe3fe0] [c00081fc] __do_irq+0x28/0x80
> [effe3ff0] [c000873c] __do_IRQ+0x7c/0x84
> [c8aec430] [c8aec610] 0xc8aec610
   ^ 
That's your lowest frame on the process stack. It should actually extend
down to c8aec000, so you had a little bit of space left.

CONFIG_DEBUG_STACKOVERFLOW warns when you have less than 1/4 of the stack
free. You could try turning it off and see if the system survives.

The other thing to try would be increasing the THREAD_SHIFT to 14.

cheers