Re: stack overflow on Sparc64

From: Mikulas Patocka
Date: Fri Jun 20 2008 - 11:47:35 EST


It could still be improved a lot, however.

Long-term consideration: Is it possible to implement interrupt stacks on
sparc64? Functions on sparc eat stack much more aggressively than on other
architectures (minimum stack size for a function is 192 bytes).

I had a patch but at the time I wrote it (several years ago) I
couldn't make it stable enough to put mainline, I may resurrect it.

I just did a quick scan and I can't find the last copy I had, and
things have changed enough that I'd probably work from scratch
anyways.

But the level of recursion possible by the current device layer is
excessive and needs to be curtained irrespective of these generic
wakeup and sparc64 interrupt stack issues.

I took another few traces (to track the whole stack content) and there is another problem: nested interrupts. Does Sparc64 limit them somehow?

sys_call_table
timer_interrupt
irq_exit
do_softirq
__do_softirq
run_timer_softirq
_spin_unlock
sys_call_table
handler_irq
handler_fasteoi_irq
handle_irq_event
ide_intr
ide_dma_intr
task_end_request
ide_end_request
__ide_end_request
...

Mikulas
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