The jtreg regression harness uses 2 minutes as the default
timeout value for forcing a test failure.

  http://openjdk.java.net/jtreg/tag-spec.txt

To accomodate slower configurations the harness is run
with a 4x timeoutFactor from the defualt test makefile.

jdk/test/Makefile
  JTREG_TIMEOUT_OPTION = -timeoutFactor:4

Attached is a list of rgeression tests that specfiy
a shorter test that the default 2 minutes.

The speculation is that shorter timeouts were used during
testing of specific bug fixes. On slower machines these tests
may timeout prematurely.