Re: waitid breaks telnet

[Joe Korty <joe.korty@ccur.com>]

On Wed, Dec 01, 2004 at 05:49:06PM -0500, Joe Korty wrote:
> On Wed, Dec 01, 2004 at 05:30:14PM -0500, Joe Korty wrote:
> > On Wed, Dec 01, 2004 at 11:41:41AM -0800, Andrew Morton wrote:
> > > Roland McGrath <roland@redhat.com> wrote:
> > > >
> > > > I've had no luck reproducing that, so there isn't much I can do.
> > > 
> > > Did you try bare 2.6.10-rc2?
> > > 
> > > >  The last
> > > > time someone thought the waitid change broke something random, it was the
> > > > perturbation of the compiled code vs the issue that the kernel's assembly
> > > > code doesn't follow the same calling conventions the compiler expects.
> > > 
> > > Could be that, but I was able to reproduce it on 2.6.10-rc2 with
> > > gcc-2.95.4, with which -mregparm is disabled.
> > > 
> > > Still.  It would be interesting if Joe could retest with CONFIG_REGPARM=n?
> > 
> > CONFIG_REGPARM is not set in all of my kernels (just verified).
> 
> More info: I exclusively use CONFIG_SMP and CONFIG_PREEMPT.
> If it is a race either or both of these is likely to
> be involved.

Ok, I rebuilt 2.6.9 with CONFIG_PREEMPT=n and telnet failed
the one time I tried it.

Then I built with CONFIG_PREEMPT=n and CONFIG=SMP=n and
the first telnet attempt succeeded.  I then tried six
more telnet attempts, two of those failed and the rest
succeeded.

Since my earlier testing usually was of only 1 (sometimes
2) telnet attempts per boot, they too may have had some
ratio of success/failure other than 100% or 0%.

Joe