[llvm-dev] Benchmark LNT weird thread behaviour

[Renato Golin via llvm-dev]

Hi James/Chris,

You guys have done this before, so I'm guessing you can help me
understand what's going on.

If my buildbot config is:

jobs=2,
nt_flags=['--cflag', '-mcpu=cortex-a15', '--use-perf', '--threads=1',
'--build-threads=4']

It uses -j4 for build, -j2 for running the tests:

http://buildmaster.tcwglab.linaro.org/builders/clang-native-arm-lnt-perf/builds/35/steps/test-suite/logs/stdio

If my buildbot config is:

jobs=4,
nt_flags=['--cflag', '-mcpu=cortex-a15', '--use-perf', '--threads=1',
'--build-threads=4']

It uses -j4 for build, -j4 for running the tests:

http://buildmaster.tcwglab.linaro.org/builders/clang-native-arm-lnt-perf/builds/33/steps/test-suite/logs/stdio

If my buildbot config is:

jobs=2,
nt_flags=['--cflag', '-mcpu=cortex-a15', '--use-perf', '--threads=1',
'--build-threads=2']

It uses -j2 for build, -j2 for running the tests:

http://buildmaster.tcwglab.linaro.org/builders/clang-native-arm-lnt-perf/builds/34/steps/test-suite/logs/stdio

But, on the production buildbot, my config is:

jobs=2,
nt_flags=['--cflag', '-mcpu=cortex-a15', '--use-perf', '--threads=1',
'--build-threads=2']

and it uses -j2 to build and -j1 to run the tests:

http://lab.llvm.org:8014/builders/clang-native-arm-lnt-perf/builds/98/steps/test-suite/logs/stdio

My master has up-to-date Zorg as of yesterday. The only change I did
was to comment out the unused slaves.

What am I doing wrong?

cheers,
--renato