[Users] Benchmarking

[Ian Hinder]

On 5 May 2017, at 20:38, Khamesra, Bhavesh <bhaveshkhamesra at gatech.edu> wrote:

> Hi Ian, No I do not find any backtrace files in the output directory. 

How do you know that there is a segfault? Can you post the error message?  It's possible that the segfault is not in Cactus - e.g. it could be from mpirun or some other part of the system.  If Cactus aborts with a segfault, and the run is using Carpet as the driver (i.e. the Carpet thorn is active in the parameter file), then it should write a backtrace file.  


> 
> .............................
> Bhavesh Khamesra
> Graduate Student
> Centre of Relativistic Astrophysics
> Georgia Institute of Technology
> From: Ian Hinder <ian.hinder at aei.mpg.de>
> Sent: Friday, May 5, 2017 1:13:38 PM
> To: Khamesra, Bhavesh
> Cc: Erik Schnetter; Einstein Toolkit Users
> Subject: Re: [Users] Benchmarking
>  
> 
> On 5 May 2017, at 18:43, Khamesra, Bhavesh <bhaveshkhamesra at gatech.edu> wrote:
> 
>> I have heard of such a segfault before. I assume it is caused by using too many processes or too many threads for a particular resolution. I have not yet reproduced it, and I don't know what causes it. It would be helpful if you could produce a stack backtrace or similar. On the other hand, if this segfault only appears for very inefficient configurations, then there is no urgent need to debug this, as people won't be interested in using such configurations anyway.
>> I do not think that it is caused by using too many processors. I tried it with varying number of cores from 68 (insufficient) to 204 but get the same error. Also, I am getting this error with all my BBH parameter files I have tried, so its kind of important. Is there a way to produce backtrace file using simfactory? 
> 
> Carpet should write a backtrace file into the output directory if there is a segfault.  Do you see backtrace files in
> 
> sim/output-0000/sim/backtrace.*.txt
> 
> ?
> 
> -- 
> Ian Hinder
> http://members.aei.mpg.de/ianhin

-- 
Ian Hinder
http://members.aei.mpg.de/ianhin

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.einsteintoolkit.org/pipermail/users/attachments/20170506/87350e92/attachment-0001.html