Open MPI logo

Open MPI Development Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Development mailing list

Subject: Re: [OMPI devel] detecting regcache_clean deadlocks in Open-MX
From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2009-09-21 09:37:08


Do you just want to wait for the ummunotify stuff in OMPI? I'm half
done making a merged "linux" memory component (i.e., it merges the
ptmalloc2 component with the new ummunotify stuff).

It won't help for kernels <2.6.32, of course. :-)

On Sep 21, 2009, at 9:11 AM, Brice Goglin wrote:

> Jeff Squyres wrote:
> > On Sep 21, 2009, at 5:50 AM, Brice Goglin wrote:
> >
> >> I am playing with mx__regcache_clean() in Open-MX so as to have
> OpenMPI
> >> cleanup the Open-MX regcache when needed. It causes some
> deadlocks since
> >> OpenMPI intercepts Open-MX' own free() calls. Is there a "safe"
> way to
> >> have Open-MX free/munmap calls not invoke OpenMPI interception
> hooks?
> >>
> >
> > Not ATM, no.
> >
> >> Or
> >> is there a way to detect the caller of free/munmap so that my
> >> regcache_clean does nothing in this case? Otherwise, I guess I'll
> have
> >> to add a private malloc implementation inside Open-MX and hope
> OpenMPI
> >> won't see it.
> >>
> >
> >
> > Can you structure your code to not call free/munmap inside the
> handler?
>
> The first problem is actually about thread-safety. Most Open-MX
> functions, including mx_regcache_clean(), take a pthread mutex. So I
> would have to move all free/munmap outside of the locked section.
> That's
> probably feasible but requires a lot of work :)
>
> Brice
>
> _______________________________________________
> devel mailing list
> devel_at_[hidden]
> http://www.open-mpi.org/mailman/listinfo.cgi/devel
>

-- 
Jeff Squyres
jsquyres_at_[hidden]