[PATCH] pipe2 for Linuxulator

[Alexander Best]

On Sun Apr 15 12, Alexander Leidinger wrote:
> On Sun, 15 Apr 2012 19:04:08 +0000 Alexander Best <arundel at freebsd.org>
> wrote:
> 
> > On Sun Apr 15 12, Alexander Leidinger wrote:
> > > On Sun, 15 Apr 2012 18:16:13 +0000 Alexander Best
> > > <arundel at freebsd.org> wrote:
> 
> > > > also...even after installing a fresh kernel and world with dtrace
> > > > enabled, the "check_error.d" and "trace_futexes.d" fail and
> > > > sometimes even render the flash instance unusable.
> > > 
> > > I assume with unusable you mean not fast enough. Well... buy a
> > > faster CPU. No, just kidding. Depending on what a D script does and
> > > how many probes are enabled in the D script, it is not unexpected
> > > that the system slows down. As told above, the scripts show what is
> > > possible. For real debugging you may want to use stripped down
> > > versions.
> > 
> > no actually. what i meant by "unusable" is that the d-scripts
> > themself crash the flash instances.
> 
> Uhm... this is unexpected. DTrace disables destructive actions by
> default, and I do not activate them. Maybe some timing-sensitive code
> in the flash-player which does not handle the case that some parts can
> take longer than expected? I assume there is not bug in DTrace itself.
> There could be a bug in my patch, but I would assume it is not a
> heisen-bug as described here (the probes are handled by
> DTrace-macros, just the variables which are provided to D scripts
> are different from other probes).

this sounds reasonable. after exiting the dtrace script the crashed flash
instance partially returns to normal behaviour. so indeed it seems that
dtrace is having only an impact on flash's timing-code.

none of the linux processes actually crashes (that is is being terminated) in
this scenario. ps alx shows that all processes still exist.

i'll play a bit more with the dtrace scripts and see if i can remove more
stuff that isn't important for futex related matters.

good night.
alex

> 
> Bye,
> Alexander.
> 
> -- 
> http://www.Leidinger.net    Alexander @ Leidinger.net: PGP ID = B0063FE7
> http://www.FreeBSD.org       netchild @ FreeBSD.org  : PGP ID = 72077137