en with "constant TSC" feature (which is no longer
> constant again).
> >
> > Kind regards,
> > Alex Granovsky
> >
> >
> >
> > -Original Message- From: Gilles Gouaillardet
> > Sent: Thursday, November 27, 2014 1:13 PM
> > T
ent: Thursday, November 27, 2014 1:13 PM
> To: Open MPI Users
> Subject: Re: [OMPI users] mpi_wtime implementation
>
> Folks,
>
> one drawback of retrieving time with rdtsc is that this value is core
> specific :
> if a task is not bound to a core, then the value returned b
sky
-Original Message-
From: Gilles Gouaillardet
Sent: Thursday, November 27, 2014 1:13 PM
To: Open MPI Users
Subject: Re: [OMPI users] mpi_wtime implementation
Folks,
one drawback of retrieving time with rdtsc is that this value is core
specific :
if a task is not bound to a core, then t
Folks,
one drawback of retrieving time with rdtsc is that this value is core
specific :
if a task is not bound to a core, then the value returned by MPI_Wtime()
might go backward.
if i run the following program with
taskset -c 1 ./time
and then move it accross between cores
(taskset -cp 0 ; tas
On Nov 24, 2014, at 12:06 AM, George Bosilca wrote:
> https://github.com/open-mpi/ompi/pull/285 is a potential answer. I would like
> to hear Dave Goodell comment on this before pushing it upstream.
>
> George.
I'll take a look at it today. My notification settings were messed up when you
https://github.com/open-mpi/ompi/pull/285 is a potential answer. I would
like to hear Dave Goodell comment on this before pushing it upstream.
George.
On Wed, Nov 19, 2014 at 12:56 PM, George Bosilca
wrote:
> Dave,
>
> You’re right, we screwed up (some #define not correctly set). I have a
>
Dave,
You’re right, we screwed up (some #define not correctly set). I have a patch,
I’ll push it asap.
George.
> On Nov 19, 2014, at 05:19 , Dave Love wrote:
>
> "Daniels, Marcus G" writes:
>
>> On Mon, 2014-11-17 at 17:31 +, Dave Love wrote:
>>> I discovered from looking at the mpiP
"Daniels, Marcus G" writes:
> On Mon, 2014-11-17 at 17:31 +, Dave Love wrote:
>> I discovered from looking at the mpiP profiler that OMPI always uses
>> gettimeofday rather than clock_gettime to implement mpi_wtime on
>> GNU/Linux, and that looks sub-optimal.
>
> It can be very expensive in
On Mon, 2014-11-17 at 17:31 +, Dave Love wrote:
> I discovered from looking at the mpiP profiler that OMPI always uses
> gettimeofday rather than clock_gettime to implement mpi_wtime on
> GNU/Linux, and that looks sub-optimal.
It can be very expensive in practice, especially for codes that ha
I discovered from looking at the mpiP profiler that OMPI always uses
gettimeofday rather than clock_gettime to implement mpi_wtime on
GNU/Linux, and that looks sub-optimal. I don't remember what the
resolution of gettimeofday is in practice, but I did need to write a
drop-in replacement for benchm
Hello,
use RDTSC (or RDTSCP) to read TSC directly
Kind regards,
Alex Granovsky
-Original Message-
From: maxinator333
Sent: Monday, November 10, 2014 4:35 PM
To: us...@open-mpi.org
Subject: [OMPI users] MPI_Wtime not working with -mno-sse flag
Hello again,
I have a piece of code
On some platforms, the MPI_Wtime function essentially uses gettimeofday() under
the covers.
See this stackoverflow question about -mno-sse:
http://stackoverflow.com/questions/3687845/error-with-mno-sse-flag-and-gettimeofday-in-c
On Nov 10, 2014, at 8:35 AM, maxinator333 wrote:
> Hello
Hello again,
I have a piece of code, which worked fine on my PC, but on my notebook
MPI_Wtime and MPI_Wtick won't work with the -mno-sse flag specified.
MPI_Wtick will return 0 instead of 1e-6 and MPI_Wtime will also return
always 0. clock() works in all cases.
The Code is:
#include
#inclu
On 9/12/06, Aidaros Dev wrote:
Hi all,
Im using cluster and mpich in Redhat.
When i printf MPI_Wtime value, it return such like 0.224554 or 0.755654,
even sometime return 0.0.
I check my system time
$date
Tue Sep 12 15:15:16 MYT 2006 , means system time is ok.
Any idea?
MPI_Wtime sho
Hi all,
Im using cluster and mpich in Redhat.
When i printf MPI_Wtime value, it return such like 0.224554 or 0.755654,
even sometime return 0.0.
I check my system time
$date
Tue Sep 12 15:15:16 MYT 2006 , means system time is ok.
Any idea?
--
A friend in need Is a friend indeed
alf Of Michael Kluskens
> Sent: Monday, June 19, 2006 1:33 PM
> To: Open MPI Users
> Subject: [OMPI users] MPI_Wtime
>
> Is anyone using MPI_Wtime with any version of OpenMPI under
> Fortran 90?
>
> I got my program to compile with MPI_Wtime commands but the
> diff
Is anyone using MPI_Wtime with any version of OpenMPI under Fortran 90?
I got my program to compile with MPI_Wtime commands but the
difference between two different times in the process is always zero.
When compiling against OpenMPI I have to specify
mytime = MPI_Wtime
For other MPI's I spe
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