[9] RFR (S): 8068269: RTM tests that assert on non-zero lock statistics are too strict in RTMTotalCountIncrRate > 1 cases

Filipp Zhinkin filipp.zhinkin at oracle.com
Tue Dec 30 08:42:11 UTC 2014

Hi all,

please review a fix for 8068269.
A few RTM tests assert on non-zero locks count in 
PrintPreciseRTMLockingStatistics entries, but at the same time 
these tests use RTMTotalCountIncrRate > 1.

If RTMTotalCountIncrRate > 1, then locks count will be incremented
only when (rdtsc() & (RTMTotalCountIncrRate - 1) == 0) (*).

We may never met condition (*) during a short test run and
in such case test will fail.

An there is one more rare case: when we didn't met (*) and
there were no transactional execution abortions.
In such case counters will contain zero, JVM will consider
it unused and won't print it out.

To fix these issues assertions on non-zero locks count
were removed for cases where RTMTotalCountIncrRate > 1
and in order to avoid issue with zero counters affected
test is now forcing one transactional execution abort.

Bug id: https://bugs.openjdk.java.net/browse/JDK-8068269
Webrev: http://cr.openjdk.java.net/~fzhinkin/8068269/webrev.01/
Testing: manual & automaed on host w/ HSW CPU, JPRT


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