Re: BitKeeper repo for KGDB

Matt Mackall
2004-02-09T17:39:03Z

On Mon, Feb 09, 2004 at 08:50:13AM -0700, Tom Rini wrote:
> On Sun, Feb 08, 2004 at 07:29:51PM -0600, Matt Mackall wrote:
> > On Fri, Feb 06, 2004 at 04:02:54PM -0700, Tom Rini wrote:

> > > if (!netpoll_trap() && len == 8 && !strncmp(msg, "$Hc-1#09", 8))
> > > - printk(KERN_CRIT "Someone is trying to attach\n");
> > > -// kgdb_schedule_breakpoint();
> > > + breakpoint();
> > >
> > > for (i = 0; i < len; i++) {
> > > - if (msg[i] == 3) /* Check for ^C? */
> > > - printk(KERN_CRIT "Someone is trying to ^C?\n");
> > > -// kgdb_schedule_breakpoint();
> > > + if (msg[i] == 3)
> > > + breakpoint();
> >
> > The kgdb_schedule_breakpoint stuff in -mm didn't just appear to make
> > things more complicated, it is in fact necessary. You cannot
> > reasonably expect to break deep inside the network stack IRQ handler
> > and then send more packets out the same interface. Expect especially
> > nasty results on SMP. It only works for the serial case because that
> > path is a priori known to be lockless.
>
> Ah, hmm... I don't suppose there's any way to do this w/o touching
> every arch's do_IRQ, is there?

Probably not. On the other hand, it provides yet more motivation for
an irq handling refactoring in 2.7.

--
Matt Mackall : http://www.selenic.com : Linux development and consulting