Re: Calling current() from interrupt context

From: Kenn Humborg (kenn@linux.ie)
Date: Sun Oct 08 2000 - 20:21:09 EST


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

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Sun Oct 15 2000 - 21:00:11 EST