Re: Test-lock hang (not 100% reproducible) on GNU/Linux

[Pavel Raiskup]

On Saturday, December 24, 2016 6:52:07 PM CET Bruno Haible wrote:
> Wow, a 30x speed increase by using a lock instead of 'volatile'!
> 
> Thanks for the testing. I cleaned up the patch to do less
> code duplication and pushed it.

Thanks, that's nice speedup!  And sorry for the delay..

I still see infinite hang on ppc64le (sometimes), as discussed in [1].  It
looks like starvation of writers in test_rwlock().

Could we set PTHREAD_RWLOCK_PREFER_WRITER_NP (in test-lock.c) to avoid
those issues?  One thing I'm afraid of is that writers could finish too
early.  Could we could artificially slow them down?

[1] 
https://lists.fedoraproject.org/archives/list/address@hidden/thread/PQD576JZLERFY6ROI3GF7UYXKZIRI33G/

Pavel