Re: No user space access during irq?

Alexander Viro (viro@math.psu.edu)
Mon, 8 Feb 1999 05:25:09 -0500 (EST)


On Mon, 8 Feb 1999, Till Harbaum wrote:

> > > the machine just crashes. Am i not allowed to use the
> > > above functions in an interrupt?
>
> > Interrupt may happen during the timeslice of another process. put_user
> > refers to the given address in the address space of *current* process.
>
> Uhm, yes (i feel like an idiot). Is there a solution for my problem?
> I know i am not allowed to call the scheduler during the irq. Is
> there another way of gaining access to the correct user space?

Lock the page in core, translate its address to physical and write there.
If you are after fast IO you don't want the thing to be swapped out
anyway.

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