Re: Linux 2.4.1-ac15

From: Philipp Rumpf (prumpf@mandrakesoft.com)
Date: Thu Feb 22 2001 - 19:01:03 EST


On Thu, Feb 22, 2001 at 10:22:56AM +0000, Alan Cox wrote:
> > > We can take page faults in interrupt handlers in 2.4 so I had to use a
> > > spinlock, but that sounds the same
> >
> > We can? Woah, please explain.
>
> vmalloc does a lazy load of the tlb. That can lead to the exception table
> being walked on an IRQ

But will that ever get to the search_exception_table code ? (I don't
think that would be valid, but other exceptions in interrupts might be -
cf some of the self-modifying mmx copy versions).

Oh, like rdmsr_eio on SMP systems. Definitely valid, and it can deadlock
with both the semaphore and the spinlock AFAICS. Alan, is this an issue ?
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