Alan Cox wrote:
>
> > Yeas it is stil the same as 2.4.5-ac1, but did not
> > happen with 2.4.5; You can try running pppd in the
> > console (tty1) without any argument.
>
> Looks like an interaction with the newer console locking code. The BUG() is
> caused when the ppp code tries to write to the console from inside an
> interrupt handler [now not allowed]
I wondered if there were more cases.
In the (as-yet-unsent) Linus patch I've added an
if (in_interrupt()) {
shout_loudly();
return;
}
in three places to catch this possibility. I'll prepare
a -ac diff.
This is a fundamental problem.
- The console is a tty device
- tty devices are callable from interrupts
- the console is very stateful and needs locking
- the locking must be interrupt-safe (irqsave)
- the console is very slow.
net result: we block interrupts for ages. It's
an exceptional situation. I hope Linus buys this
line of reasoning :)
-
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This archive was generated by hypermail 2b29 : Thu May 31 2001 - 21:00:36 EST