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)
<jsquyres@cisco.com> wrote:
On May 7, 2012, at 2:39 PM, Jingcha Joba wrote:
> 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.
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).
What happens before or after that is not covered in the scope of MPI_Wtime().