Re: Calling current() from interrupt context

[Kenn Humborg]

On Mon, Oct 09, 2000 at 02:20:27AM +0200, Andi Kleen wrote:
> 2.4 TCP code relies on current being valid in a softirq.

Well, then as long as Linux guarantees that there is always a 
valid 'current task' on a CPU, then I can special-case the 
called-from-interrupt case.  The previous kernel stack pointer
is accessible from another processor register, so I can go in
there and pull it out and use it to calculate current.

Is it possible to get an interrupt during context switching,
for example?  Or any other window during which there isn't
a valid current?

And what the hell does TCP need current for anyway?

Later,
Kenn

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