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Re: [bgl-discuss] NAN for mpi_wtime() ?




Yes - but this is about a 30 sec. elapsed time -- Sorry,
I forgot to mention that in the original email.

Paul



On Sat, 29 Oct 2005, Anthony Chan wrote:

>
> I think this timer bug is there ever since BGL arrives, a simple
> java timing code on the front-end node has similar problem.
>
> clog2TOslog2 -o tmp.slog2 tmp.clog2
> .....
> timeElapsed between 1 & 2 = 105 msec
> timeElapsed between 2 & 3 = -1130612245368 msec
>
> It has something to do with how long the 2nd timer runs, if it is
> short enough.  It will work fine.
>
> But the MPI_Wtime() on the compute nodes seems to work fine,
> at least from MPE's respective.
>
> A.Chan
>
> On Sat, 29 Oct 2005, Paul Fischer wrote:
>
> >
> > Does anyone have a clue why I should get NAN as a return
> > result for mpi_wtime ?
> >
> > I have the following code fragment:
> >
> >       t0 = mpi_wtime()
> >       gs_handle = fgs_init(glo_num,ntot,np)
> >       t1 = mpi_wtime()
> >       et = t1-t0
> >       if (nid.eq.0) then
> >          write(6,1) et,t0,t1,nx,ntot,ngv,np,gs_handle
> >     1    format('fgs_init A:',1p3e11.4,' seconds ',i4,4i10)
> >       endif
> >
> > which produces:
> >
> >  fgs_init A:   -NAN 1.1306E+09   -NAN seconds    2       960   16320 128 2
> >  fgs_init A:   -NAN 1.1306E+09   -NAN seconds    4      7680  423360 128 3
> >  fgs_init A:   -NAN 1.1306E+09   -NAN seconds    6     25920 1944000 128 4
> >  fgs_init A:   -NAN 1.1306E+09   -NAN seconds    8     61440 5315520 128 5
> >
> > There is no problem w/ the first mpi_wtime() call, only w/ the second??
> >
> > Thanks -- Paul
> >
> >
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> >
>
>

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