[mpich-discuss] Hydra binding questions

Jain, Rohit Rohit_Jain at mentor.com
Fri Aug 5 12:38:35 CDT 2011


I have already filed a ticket.
Is it possible to get a patch for this fix for 1.4, so we can try and see how binding is done?


-----Original Message-----
From: mpich-discuss-bounces at mcs.anl.gov [mailto:mpich-discuss-bounces at mcs.anl.gov] On Behalf Of Pavan Balaji
Sent: Tuesday, August 02, 2011 9:49 AM
To: mpich-discuss at mcs.anl.gov
Cc: Jain, Rohit
Subject: Re: [mpich-discuss] Hydra binding questions

On 08/01/2011 06:38 PM, Jain, Rohit wrote:
> 1)Is there any debug output by Hydra, which tells particular
> core/processor binding (core numbers) associated with a process? We can
> use this info to see variation of binding methods on different
> architectures.

Yes, good point. We don't print out the binding information in the 
verbose output currently. I'll add that in. Can you add a ticket for 
this? https://trac.mcs.anl.gov/projects/mpich2/newticket

> 2)We expected cpu:sockets and cache:l3 binding to behave same on an AMD
> box due to its layout (2 processors with 6 cores each). But, there is
> difference in performance of about 10%. Is that expected? Again, any
> information on binding will help, currently it is black box for us of
> what Hydra does.

Once I add print out the binding, you'll know what binding it's using. 
That might help debug this.

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