ShenEOS scaling issues

[brycelelbach]

[reported by manderson] [Trac time Tue Mar 27 22:32:58 2012] The shen eos component now performs comparable to the standalone fortran equivalent from C. Ott when run on 1 thread. However, it does not scale at all:

./sheneos_test --num-workers 1 --hpx:threads 1 --num-partitions 1 gives 0.0405 sec
./sheneos_test --num-workers 2 --hpx:threads 2 --num-partitions 2 gives 0.1280 sec
./sheneos_test --num-workers 4 --hpx:threads 4 --num-partitions 4 gives 0.2280 sec
./sheneos_test --num-workers 8 --hpx:threads 8 --num-partitions 8 gives 0.5500 sec

Varying the number of partitions alters these numbers; however, the optimal result is to keep the same number of partitions as the number of threads, as shown here.

I have eliminated the time overhead associated with shen_connect in these measurements as well as all other unrelated overhead. I have removed the srand and random_shuffle in case they were affecting the scaling.

The shen eos component does not scale at all. In fact, running the same amount of work on one thread is nearly twice as fast compared to running on eight threads:

./sheneos_test --num-workers 8 --hpx:threads 1 --num-partitions 1 gives 0.2350 sec

[brycelelbach]

[comment by manderson] [Trac time Tue Mar 27 22:34:17 2012] Note that the scaling test performed here are weak scaling tests. Strong scaling test results are even worse.

[brycelelbach]

[comment by manderson] [Trac time Wed Mar 28 17:52:43 2012] the latest numbers...

40 x 40 x 40
1 0.0728 (100 partition)
2 0.0859 (100 partitions)
4 0.108 (300 partitions)
8 0.151 (200 partitions)
12 0.220 (300 partitions)

control case: 0.0549

100 x 100 x 100
1 1.096 (300 partitions)
2 1.374 (180 partitions)
4 1.650 (350 partitions)
8 2.589 (550 partitions)

[brycelelbach]

[comment by blelbach] [Trac time Sun Apr 22 05:30:30 2012] Hartmut, what's the progress on this? Does the bulk interface stuff resolve this?

[brycelelbach]

[comment by blelbach] [Trac time Sun Jun 3 21:26:57 2012] Can I get an update on the status of this, please?

[hkaiser]

I think those have been resolved some time ago. Closing the ticket now...