https://github.com/openjdk/jdk/blob/master/test/hotspot/jtreg/compiler/gcbarriers/UnsafeIntrinsicsTest.java

Z and Shenandoah runs both take about 25 sec each, so a total of 50sec. This is one of the slowest tests in tier1.

compiler/gcbarriers/UnsafeIntrinsicsTest_Z.jtr 24278
compiler/gcbarriers/UnsafeIntrinsicsTest_Shenandoah.jtr 23412

It seems that it runs 5 subtests, and that all of them are supposed to take 4 seconds.
This would therefore take at least 20sec.

Is this justified? Could we do it in fewer seconds?
If we need to keep it as is, can we move it to a higher tier?

We can split the 5 subtasks into separate run statements, at least this makes it run in parallel.
Probably moving it as high as tier5 could be ok.