So in the above stated example, end-start will be: <whatever the solver took> + 20ms ?
On Mon, May 7, 2012 at 1:42 PM, Jeff Squyres (jsquyres) <firstname.lastname@example.org>
On May 7, 2012, at 2:39 PM, Jingcha Joba wrote:MPI_Wtime() doesn't tell you any of this stuff. It just tells you the time *right now*. Basically, MPI_Wtime() can be used to compute wall-clock timings (which are really the only relevant timings when measuring delivered performance, anyway).
> OK.This explains that if a process gets "migrated" from one CPU to another, the time is not "affected". But it still doesn't explain if the process gets scheduled back to the same CPU.
What happens before or after that is not covered in the scope of MPI_Wtime().