[ruby-core:64750] Re: [ruby-trunk - Bug #10202] [Open] TestBenchmark#test_realtime_output breaks on ARM

From: Eric Wong <normalperson@...>
Date: 2014-09-03 17:51:09 UTC
List: ruby-core #64750
v.ondruch@tiscali.cz wrote:
> I observe following error on ARM:
> 
> ~~~
>   3) Failure:
> TestBenchmark#test_realtime_output [/builddir/build/BUILD/ruby-2.2.0-r47372/test/benchmark/test_benchmark.rb:159]:
> Expected 1.0 to be < 0.999977873172611.

The real bug might be a timer firing too soon.

Can you show us the output of: strace -Tvf ruby -e 'sleep 1'

I mainly care about the timing of FUTEX_WAIT_BITSET(_PRIVATE) and poll
syscalls.  Thank you.

> It seems to be introduced by r47360. Reverting the commit makes test
> suite to pass once again.

Reverting just the change to lib/benchmark.rb?  Or reverting the test
case, too?

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