Hi Dave, Gilles, list
There is a problem with knem in OMPI 1.8.3.
A fix is supposed to come on OMPI 1.8.4.
Please, see this long thread:
http://www.open-mpi.org/community/lists/users/2014/10/25511.php
Note also, as documented in the thread,
that in the OMPI 1.8 series "vader" replaces "sm" as th
It could be because configure did not find the knem headers and hence knem is
not supported and hence this mca parameter is read-only
My 0.2 us$ ...
Dave Love さんのメール:
>Why can't I set parameters like this (not the only one) with 1.8.3?
>
> WARNING: A user-supplied value attempted to override th
Why can't I set parameters like this (not the only one) with 1.8.3?
WARNING: A user-supplied value attempted to override the default-only MCA
variable named "btl_sm_use_knem".
No worries :)
2014-11-27 14:20 GMT+01:00 Jeff Squyres (jsquyres) :
> Many thanks!
>
> Note that it's a holiday week here in the US -- I'm only on for a short
> time here this morning; I'll likely disappear again shortly until next
> week. :-)
>
>
>
> On Nov 27, 2014, at 8:12 AM, Nick Papior Ande
Many thanks!
Note that it's a holiday week here in the US -- I'm only on for a short time
here this morning; I'll likely disappear again shortly until next week. :-)
On Nov 27, 2014, at 8:12 AM, Nick Papior Andersen wrote:
> Sure, I will make the changes and commit to make them OMPI specifi
Sure, I will make the changes and commit to make them OMPI specific.
I will post forward my problems on the devel list.
I will keep you posted. :)
2014-11-27 13:58 GMT+01:00 Jeff Squyres (jsquyres) :
> On Nov 26, 2014, at 2:08 PM, Nick Papior Andersen
> wrote:
>
> > Here is my commit-msg:
> >
On Nov 26, 2014, at 2:08 PM, Nick Papior Andersen wrote:
> Here is my commit-msg:
> "
> We can now split communicators based on hwloc full capabilities up to BOARD.
> I.e.:
> HWTHREAD,CORE,L1CACHE,L2CACHE,L3CACHE,SOCKET,NUMA,NODE,BOARD
> where NODE is the same as SHARED.
> "
>
> Maybe what I did
Gilles' concern is correct: we should never return timer values that go
backwards.
Perhaps the TSC-based WTIME should only be used in a process that is bound to a
single core...?
An MCA param can be used to force the switch between gettimeofday() and TSC, if
someone really wants to take their
AFAIK, Linux synchronizes all CPU timers on boot. The skew is normally no
more than 50-100 CPU cycles.
The reasons why you can observe larger differences are:
1) Main. The CPUs do not have "constant TSC" feature . Without this feature
timer frequency changes across different power states of CP
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
10 matches
Mail list logo
