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From: Tim Prins (tprins_at_[hidden])
Date: 2007-07-10 14:52:18


Is this something that Open MPI should be setting automatically?

Tim

On Tuesday 10 July 2007 02:44:04 pm George Bosilca wrote:
> I always use MX_RCACHE=2 for both MTL and BTL. So far I didn't had
> any problems with it.
>
> george.
>
> On Jul 10, 2007, at 2:37 PM, Brian Barrett wrote:
> > On Jul 10, 2007, at 11:40 AM, Scott Atchley wrote:
> >> On Jul 10, 2007, at 1:14 PM, Christopher D. Maestas wrote:
> >>> Has anyone seen the following message with Open MPI:
> >>> ---
> >>> warning:regcache incompatible with malloc
> >>> ---
> >>>
> >>> <snip>
> >>>
> >>> ---
> >>>
> >>> We don't see this message with mpich-mx-1.2.7..4
> >>
> >> MX has an internal registration cache that can be enabled with
> >> MX_RCACHE=1 or disabled with MX_RCACHE=0 (the default before MX-1.2.1
> >> was off, and starting with 1.2.1 the default is on). If it is on, MX
> >> checks to see if the application is trying to override malloc() and
> >> other memory handling functions. If so, it prints the error that you
> >> are seeing and fails to use the registration cache.
> >>
> >> Open MPI can use the regcache if you set MX_RCACHE=2. This tells MX
> >> to skip the malloc() check and use the cache regardless. In the case
> >> of Open MPI, this is believed to be safe. That will not be true for
> >> all applications.
> >>
> >> MPICH-MX does not manage memory, so MX_RCACHE=1 is safe to use unless
> >> the user's application manages memory.
> >
> > Scott -
> >
> > I'm having trouble getting the warning to go away with Open MPI.
> > I've disabled our copy of ptmalloc2, so we're not providing a malloc
> > anymore. I'm wondering if there's also something with the use of
> > DSOs to load libmyriexpress? Is your belief that MX_RCACHE=2 is safe
> > just for the BTL or for the MTL as well?
> >
> > Brian
> >
> >
> > --
> > Brian W. Barrett
> > Networking Team, CCS-1
> > Los Alamos National Laboratory
> >
> >
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