Re: libpthread cleanup: L4 port, PowerPC port

[Neal H. Walfield]

At Sat, 4 Aug 2012 15:02:46 +0200,
Thomas Schwinge wrote:
> > > master-viengoos and its successor, master-viengoos-on-bare-metal.
> > 
> > master-viengoos is an implementation of Viengoos that runs on L4.
> > viengoos-on-bare-metal runs directly on x86-64 (and it a bit more
> > advanced) and provides everything that master-viengoos does and more.
> > I unfortunately never got around to issuing the right git commands to
> > make turn it into the master branch.
> 
> Note that I'm talking about branches of the hurd/libpthread.git
> repository, which contains only the libpthread branches (as used by Hurd
> on Mach: master, old L4: master, Viengoos: master-viengoos and
> viengoos-on-bare-metal), and not the hurd/viengoos.git repository which
> contains all the other Viengoos code.

That's what I thought you meant.

> > > * signal/README: Likewise.
> > > * signal/TODO: Likewise.
> > > * signal/kill.c: Likewise.
> > > * signal/pt-kill-siginfo-np.c: Likewise.
> > > * signal/sig-internal.c: Likewise.
> > > * signal/sig-internal.h: Likewise.
> > > * signal/sigaction.c: Likewise.
> > > * signal/sigaltstack.c: Likewise.
> > > * signal/signal-dispatch.c: Likewise.
> > > * signal/signal.h: Likewise.
> > > * signal/sigpending.c: Likewise.
> > > * signal/sigsuspend.c: Likewise.
> > > * signal/sigtimedwait.c: Likewise.
> > > * signal/sigwaiter.c: Likewise.
> > > * signal/sigwaitinfo.c: Likewise.
> > > * sysdeps/generic/killpg.c: Likewise.
> > > * sysdeps/generic/raise.c: Likewise.
> > > * sysdeps/generic/sigaddset.c: Likewise.
> > > * sysdeps/generic/sigdelset.c: Likewise.
> > > * sysdeps/generic/sigemptyset.c: Likewise.
> > > * sysdeps/generic/sigfillset.c: Likewise.
> > > * sysdeps/generic/siginterrupt.c: Likewise.
> > > * sysdeps/generic/sigismember.c: Likewise.
> > > * sysdeps/generic/signal.c: Likewise.
> > > * sysdeps/generic/sigwait.c: Likewise.
> > 
> > I think these are also used by the Viengoos port.  Are you suggesting
> > to remove both the L4 and the Viengoos ports or just the L4 port?
> 
> I only intend to clean up libpthread's master branch (that is, remove its
> old L4 port).

Ok.  I still think that the above files are generic and not L4
specific.

> On libpthread's master-viengoos and viengoos-on-bare-metal
> branches, the Viengoos-specific code stays as-is, and can continue to
> evolve there, with the long-term goal of eventually merging it back into
> libpthread's master branch as a new Viengoos port of libpthread.  (I
> guess that you only started using Viengoos-specific branches for
> libpthread for the reason of being able to easily do changes in the
> generic libpthread code without disturbing/having to adapt the Hurd on
> Mach port.)

My recollection is that Hurd was in CVS at the time.  You(?) created
 libpthread.git later.

> Yes, but I think given the testing it is seeing via Debian GNU/Hurd, your
> libpthread not so bad actually.  In the long term, and given someone
> willing to do it, a NPTL port would of course be possible/preferable/...,
> too.  But I don't think that's a priority currently.

If you have time, I'd recommend that you also take a look at the
asserts and disable the more expensive ones.  For instance in
sysdeps/mach/hurd/pt-sysdep.h, _pthread_self checks that the
thread->kernel_thread matches _mach_thread_self().  This requires two
system calls!  _pthread_self should be fast...

Neal