Re: [Valgrind-developers] exp-drd patch

[Julian S. <js...@ac...>]

> > > - The exp-drd regression tests now run without producing assertion
> > > failures and without hanging on Red Hat 7.3. It doesn't make sense
> > > however to run exp-drd on Red Hat 7.3 -- while exp-drd works fine with
> > > the NPTL, more work would be required to make exp-drd work with
> > > linuxthreads.
> >
> > Is it possible to detect linuxthreads at startup and abort with an
> > explanation?  If exp-drd can't do anything useful on linuxthreads, we
> > don't want people to run it and think their program is ok.
>
> Do have any idea how many Linux systems are based on linuxthreads and
> did not yet switch to the NPTL ?
>
> What happens when you run exp-drd under linuxthreads is that lots and
> lots of false positives are printed -- exp-drd is basically unusable
> under linuxthreads.

Same with Helgrind.

I'm in two minds as to whether or not to dump LinuxThreads support
in 3.4.  NPTL is pretty much universal now.  According to Wikipedia
it first shipped in Red Hat 9, which was released on 31 March 2003.
OTOH supporting LinuxThreads, at least to the extent that V does not
crash or hang, is not a big deal, and I have no idea how many people
are running older systems.  I think enterprise users can be very
conservative about upgrading.

> at runtime. The only reliable way I know of to detect linuxthreads at
> runtime is to call getpid() [...]

We could add a configure test for it, I suppose.

J