Hi Jeff,
Thank you for your detailed explanation! I see your point and, given
what you said, I wonder if some people report user time (only) in order
to understate the execution time of their algorithms/programs.
Seems like the best solution is to have user, system, and MPI times with
the
FWIW, I *always* report MPI application time in wall-clock seconds
time. I know that some people (even among the OMPI developers)
disagree with me, but to me, there's nothing else that you can measure
that makes sense.
Case in point: when using the OpenFabrics network stack, very little
Hi Reuti,
I have to admit that I'm so familiar with SGE, but I'll take a look at
it so that I'll learn something. In my current situation, I don't
/need/ to report a user time. I was just wondering if it has any
meaning and what people mean when they show numbers or a graph and just
says "
Hi Fabian,
Thank you for clarifying things and confirming some of the things that I
thought. I guess I have a clearer understanding now.
Fabian Hänsel wrote:
H, I guess user time does not matter since it is real time that
we are interested in reducing.
Right. Even if we *could*
Hi Ray,
with the Tight Integration of Open MPI into SGE (http://
gridengine.sunsource.net/) you will get a correct accouting. Every
process created with qrsh (a replacement for ssh) will have an
additional group id attached and SGE will accumulate them all.
Depending on the size of the clu
Hi Ray,
> So, to make sure I understand what happens... This command:
>
> mpirun -np 2 myprog
>
> starts the program "mpirun" and two processes of "myprog". So, what
> the "real time" of /usr/bin/time reports is the wall clock for mpirun.
Exactly.
> Does the user time have any meaning here?
Hi Fabian,
Fabian Hänsel wrote:
On a separate topic, but related to your post here, how did you do
the timing? [Especially to so many digits of accuracy. :-) ]
two things to consider:
i) What do I actually (want to) measure?
ii) How accurate can I do that?
i)
Option iA) execution ti
Hi Ray,
> On a separate topic, but related to your post here, how did you do
> the timing? [Especially to so many digits of accuracy. :-) ]
two things to consider:
i) What do I actually (want to) measure?
ii) How accurate can I do that?
i)
Option iA) execution time of the whole program
One c
