Dopair2 vectorisation

Adds the following:

• Vectorised version of runner_dopair2_force
• Expands testActivePair to include more test cases and to also test the force pair tasks
• Creates a branching function for DOPAIR2 so that the corner pairs are calculated using the serial version of DOPAIR2
• pairs_all_force now checks if particles are active before updating them

master vs dopair2-vectorisation

Note: vectorisation is turned on in both cases. We get some speedup:

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master
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Wall clock time for: 4097 time steps
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1 threads: 7913824.55
2 threads: 4074811.253
4 threads: 2112665.346
8 threads: 1175271.211
16 threads: 756702.398

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Parallel Efficiency for: 4097 time steps
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1 threads: 1.0
2 threads: 0.971066395305
4 threads: 0.936473985928
8 threads: 0.84170194887
16 threads: 0.6536440689

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dopair2-vectorisation
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Wall clock time for: 4097 time steps
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1 threads: 7524620.125
2 threads: 3864171.962
4 threads: 2000113.58
8 threads: 1115386.591
16 threads: 730397.59

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Parallel Efficiency for: 4097 time steps
------------------------------------
1 threads: 1.0
2 threads: 0.973639397909
4 threads: 0.940524103261
8 threads: 0.843274899676
16 threads: 0.643880489546

poorer scaling, but we already knew that would happen.

I still need to tidy the branch up a bit and remove the debug code into a separate branch so it is not ready for merging yet. I just wanted somewhere to put the scaling plot.

Ok, thanks. That's about a 5% speed-up on 1 core and 3.6% on 16 cores. What's the speed-up in your DOPAIR tests ?

It's not great. 1.19x for the edge interactions and 2.06x for the face interactions. However, that's with the Wendland C2 kernel.

Added 1 commit:

• e2a49f88 - Removed debugging of interactions.

Added 1 commit:

• 77606a7e - Formatting.

Added 1 commit:

• 4b3fc4a9 - Removed unused parameter.

Added 2 commits:

• 0b0fb47c - Removed unneeded variables.
• a0fe87bb - Fixed tolerances.

Added 1 commit:

• 5b0080ee - Refactoring.

Added 2 commits:

• 2e6965f1 - Convert index into the number of particles to loop over.
• 636b18b9 - Comments.

I'm running the jenkins builds and getting the following errors with testDump and testLogger:

[dc-will2@cosma-f.cosma swiftsim]$ make check > log
[37433340.3] dump.c:dump_init():129: Failed to create dump file '/tmp/dump_test.out' (Permission denied).
/bin/sh: line 5: 32301 Aborted                 (core dumped) ${dir}$tst
[37433336.1] dump.c:dump_init():129: Failed to create dump file '/tmp/dump_test.out' (Permission denied).
/bin/sh: line 5: 32551 Aborted                 (core dumped) ${dir}$tst
make[2]: *** [check-TESTS] Error 1
make[1]: *** [check-am] Error 2
make: *** [check-recursive] Error 1

are these new tests?

Not new. But you have permission problems on the files they are trying to write.

Added 4 commits:

• 636b18b9...ea50f018 - 2 commits from branch master
• 68052d22 - Merge branch 'master' into dopair2-vectorisation
• 6b06ede9 - Missing parameter descriptions.

I fixed it by running on cosma-a instead of cosma-f. Now I get this error:

[00000.0] main: Seed = 1507542110
[00000.0] main: Testing gravity for r=(5.261688e+01 3.812220e+01 4.596731e+01)
[00000.0] testGravityDerivatives.c:test():922: Relative difference (1.561253e-04) for 'D_002' (swift=1.298986e-09) and (exact=1.299189e-09) exceeds tolerance (1.000000e-04)
/bin/sh: line 5: 50691 Aborted                 ${dir}$tst
FAIL: testGravityDerivatives

when running the gcc version of the jenkins build script. I think it must be a tolerance fix for that specific seed.

Yes, it is. Please ignore this one for now. I need a to think about a more clever way of testing the gravity derivatives.

I've deleted the /tmp/dump_test.out from cosma-f, so you could run there now, but please don't as that would break jenkins. Matthieu, this test needs to make up a random name and remove() the file when it exits, or not write into a common directory, otherwise it will always be a problem.

Thanks for that. I'll need to clean up this test. It's linked to the particle logging systems which is not in use now.

Added 2 commits:

• 94f08694 - Use cell location.
• a0a916ff - Missed tolerance file in the distro.

I think this branch is ready now. I've ran all the jenkins tests.

Title changed from [WIP] Dopair2 vectorisation to Dopair2 vectorisation