Let total time on my slot 0 process be S+C+B+I
= serial computations + communication + busy wait + idle
Is there a way to find out S?
S+C would probably also be useful, since I assume C is low.
The problem is that I = 0, roughly, and B is big. Since B is big, the
usual process timing methods don't work.
If B all went to "system" as opposed to "user" time I could use the
latter, but I don't think that's the case. Can anyone confirm that?
If S is big, I might be able to gain by parallelizing in a different
way. By S I mean to refer to serial computation that is part of my
algorithm, rather than the technical fact that all the computation is
serial on a given slot.
I'm running R/RMPI.