Re: IDE + SMP Lockup (no OOPS) in 2.2.12, 2.2.10

Alan Cox (alan@lxorguk.ukuu.org.uk)
Wed, 29 Sep 1999 16:40:03 +0100 (BST)


> >>EIP: c01d3455 <stext_lock+255d/4a88>=0A=
> Trace: c0197828 <ide_dma_intr+0/90>=0A=

Ok so it took an IRQ and gets stuck waiting on a lock - looks like
the hwgroup->spinlock

> Aiee, killing interrupt handler=0A=
> Kernel panic: Attempted to kill the idle task!=0A=

This second trace is the other CPU (perfect....)

> >>EIP: c010aee0 <disable_irq+34/40>=0A=
> Trace: c0189957 <ide_do_request+2f7/550>=0A=
> Trace: c0189c2c <do_hwgroup_request+48/5c>=0A=

Which makes it all to clear

Ok whats happened is this

CPU0 CPU1
take hwgroup spinlock
take an irq
disable_irq
[wait for IRQ completion]
try to take hwgroup spinlock

Alan

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