[Pw_forum] PW taskgroups and a large run on a BG/P

Paolo Giannozzi giannozz at democritos.it
Mon Feb 2 15:09:09 CET 2009


David Farrell wrote:

> In my test of 1 pool of 1024 procs with 32 taskgroups, the output looked
> like this:
> Proc/  planes cols     G    planes cols    G      columns  G
>      Pool       (dense grid)       (smooth grid)      (wavefct grid)
>        1     15    162    50122   15    162    50122     42     6294
>        2      0    162    50122    0    162    50122     42     6294
>        3      0    162    50122    0    162    50122     42     6294
>        4      0    162    50122    0    162    50122     42     6294
>        5      0    162    50122    0    162    50122     42     6294
> ...
>       32      0    164    50136    0    164    50136     42     6290
>       33     15    164    50136   15    164    50136     42     6290
>       34      0    164    50136    0    164    50136     42     6290
>  
> Which seems to indicate that there are processors that aren't getting 
> any planes and that the FFT grid is *not* being reproduced within each 
> taskgroup. 

or that the output does not reflect what is going pon. This seems to
me much more likely, since the goal of the task group stuff is to be
able to use a number of processors larger than the number of planes
along direction 3, without having processors idling during the FFT

Paolo
-- 
Paolo Giannozzi, Democritos and University of Udine, Italy


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