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Subject: [OMPI devel] Too many fds per a.out in 1.3
From: Rolf Vandevaart (Rolf.Vandevaart_at_[hidden])
Date: 2009-08-14 17:24:07


Ralph:
(Or anyone else...)

As was reported on the user's list, we are consuming about 12 fds per
a.out. I have reproduced this with the 1.3 branch. I also have run
with the trunk, and we only consume about 6 fds per a.out.

 From what I can tell, in the 1.3 branch we are opening 3 pipes that we
do not need. I have traced this to the fact that we call
orte_iof_base_setup_prefork() twice for each a.out that we fork/exec.
The calls occur from odls_default_fork_local_proc().

In the trunk, we only call the function once. It looks like we made a
change in the trunk version of odls_default_module.c 12 months ago that
change the way the trunk behaved.

https://svn.open-mpi.org/trac/ompi/changeset/19275/trunk/orte/mca/odls/default/odls_default_module.c

If we fix this problem, then we can reduce the number of fds per a.out
from 12 to 6.

I am looking for some thoughts on this issue as the changeset I refer to
was done to fix other issues. There is no mention about opening pipes
unnecessarily.

Rolf

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