Open MPI logo

Open MPI Development Mailing List Archives

  |   Home   |   Support   |   FAQ   |  

This web mail archive is frozen.

This page is part of a frozen web archive of this mailing list.

You can still navigate around this archive, but know that no new mails have been added to it since July of 2016.

Click here to be taken to the new web archives of this list; it includes all the mails that are in this frozen archive plus all new mails that have been sent to the list since it was migrated to the new archives.

Subject: Re: [OMPI devel] [OMPI svn-full] svn:open-mpi r23936
From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2010-10-25 20:22:21


I dug into this a bit.

The problem is in the SM BTL init where it's waiting for all of the peers to set seg_inited in shared memory (so that it knows everyone has hit that point). We loop on calling opal_progress while waiting.

The problem is that opal_progress() is not returning (!).

It appears that libevent's poll_dispatch() function is somehow getting an infinite timeout -- it *looks* like libevent is determining that there are no timers active, so it decides to set an infinite timeout (i.e., block) when it calls poll(). Specifically, event.c:1524 calls timeout_next(), which sees that there are no timer events active and resets tv_p to NULL. We then call the underlying fd-checking backend with an infinite timeout.

Bonk.

Anyone more familiar with libevent's internals know why this is happening / if this is a change since the old version?

On Oct 25, 2010, at 6:07 PM, Jeff Squyres wrote:

> On Oct 25, 2010, at 3:21 PM, George Bosilca wrote:
>
>> So now we're in good shape, at least for compiling. IB and TCP seem to work, but SM deadlock.
>
> Ugh.
>
> Are you debugging this, or are we? (i.e., me/Ralph)
>
> --
> Jeff Squyres
> jsquyres_at_[hidden]
> For corporate legal information go to:
> http://www.cisco.com/web/about/doing_business/legal/cri/
>

-- 
Jeff Squyres
jsquyres_at_[hidden]
For corporate legal information go to:
http://www.cisco.com/web/about/doing_business/legal/cri/