test floatscale and simplescale fail on 32bit

[olafhering]

dune runtest fails on i586 devel:languages:ocaml/ocaml-parmap. The result of Array.make is too large. A quick change like that helps, but then it crashes with SIGSEGV:

--- a/tests/floatscale.ml
+++ b/tests/floatscale.ml
@@ -30,7 +30,11 @@ let env_string = env_param (fun x -> x)

 let nIters = env_int "nIters" 1

-let nData = env_int "nData" 10000000
+let nData_default =
+  let default = 10000000 in
+  if default > Sys.max_array_length / 2 then Sys.max_array_length / 2 else default
+
+let nData = env_int "nData" nData_default

 let nProcs = env_int "nProcs" 8

[    2s] Running[13]: (cd _build/default/tests && ./floatscale.exe)
[    4s] Command [13] got signal SEGV:
[    4s] $ (cd _build/default/tests && ./floatscale.exe)
[    4s] nData 2097151
[    4s] Test: normal parmap
[    4s] Testing scalability with 1 iterations on 8 to 8 cores, step 1
[    4s] Sequential execution takes 0.353521 seconds
[    4s] Speedup with 8 cores (average on 1 iterations): 0.396299 (tseq=0.353521, tpar=0.892057)
[    4s] Test: specialised array parmap
[    4s] Testing scalability with 1 iterations on 8 to 8 cores, step 1
[    4s] Sequential execution takes 0.175939 seconds
[    4s] Speedup with 8 cores (average on 1 iterations): 0.872372 (tseq=0.175939, tpar=0.201679)
[    4s] Test: specialised float array parmap
[    4s] Testing scalability with 1 iterations on 8 to 8 cores, step 1
[    4s] Sequential execution takes 0.122668 seconds

[UnixJunkie]

Is this error due to the switch to dune?

[olafhering]

Unlikely. The docs state the Array.make size is limited, and with floats the size has to be even smaller. But if nProc and nData is reduced the tests fail anyway. I was under the impression that OCaml code can not cause memory overflow. Apparently it can crash anyway, there is even an invalid free().

I will take this opportunityl to improve my OCaml skills and debug it myself.

[UnixJunkie]

What is the make target that allows to reproduce your problem?

[olafhering]

What is the make target that allows to reproduce your problem?

make tests probably?

[UnixJunkie]

make tests
./floatscale.native
Test: normal parmap
Testing scalability with 1 iterations on 8 to 8 cores, step 1
Sequential execution takes 1.625651 seconds
Speedup with 8 cores (average on 1 iterations): 0.237331 (tseq=1.625651, tpar=6.849722)
Test: specialised array parmap
Testing scalability with 1 iterations on 8 to 8 cores, step 1
Sequential execution takes 0.496369 seconds
Speedup with 8 cores (average on 1 iterations): 0.588940 (tseq=0.496369, tpar=0.842817)
Test: specialised float array parmap
Testing scalability with 1 iterations on 8 to 8 cores, step 1
Sequential execution takes 0.283572 seconds
Speedup with 8 cores (average on 1 iterations): 1.302353 (tseq=0.283572, tpar=0.217738)

No problems with 64 bits, at least. Good luck with the debugging.

[rdicosmo]

This should now be solved with the release 1.2.1