Gary,
On 18/11/2011 6:28 AM, Gary Adams wrote:
Here's my first concrete slow machine timed out test ...
jdk/test/java/lang/concurrent/forkjoin/Integrate.java
I had been looking at tests that had a declared "timeout=xxx",
but today I just started running the java/util/concurrent
tests at a variety of clock speeds using ejdk1.7.0 and
found a test that passes when running at 600MHz and
timed out at 300Mhz. The test passes at 300 MHz if I
include "-timeout:2" on the jtreg command line.
I think I have been misunderstanding the point you've been trying to
make here.
I'm not sure there is a simple relationship here with the use of
internal delays/timeouts in a test. delays (wait long enough til XXX
should have happened) would seem to need to be scaled under the same
considerations as used for -timeout. Internal timeouts (give up after
XXX time units because something seems to have gone wrong) on the other
hand are typically much coarser/larger and so already accommodate a
range of -timeout values implicitly.
The scaling factor need to come from the environment launching the test,
but the tests need to be modified to use it.
At 600Mhz the test runs for 84 seconds (under the default
120 second timeout). At 300Mhz the test runs for 168
seconds.
Since this test does not do an internal wait or delay operation
passing in a timeout factor would not help in this case.
In general it seems that tests that declare a timeout less than 120
seconds are indicating that an early termination for the test is
acceptable.
I agree with Alan that it doesn't make sense to specify timeouts less
than the default.
Tests declaring a longer than 120 second timeout recognize that additional
processing time may be required.
Most likely the test failed somewhere sometime and bumping the timeout
fixed it. wash-rinse-repeat
Cheers,
David
I'll try a longer overnight run at 300MHz to see if I can catch some
other tests that are close to the 120 second threshold.
...
On 11/15/11 08:33 PM, David Holmes wrote:
Hi Gary,
On 16/11/2011 6:14 AM, Gary Adams wrote:
I've been scanning a number of the slow machine test
bugs that are reported and wanted to check to see if
anyone has looked into time dependencies in the regression
tests previously. From what I've been able to learn so far
individual bugs can use the "timeout" parameter to indicate to
the test harness an expected time to run.
The test harness has command line arguments where it can
filter out tests that take too long (timelimit) or can apply a
multiplier to
to the timeout when conditions are known to slow down the process
(timeoutFactor). e.g. 8X for a slow machine or running with -Xcomp
I see that there are some wrappers that can be applied around running
a particular test to allow processing before main(). Could this
mechanism
be exploited so the harness command line options could be made known
to the time dependent tests as command line arguments or as system
properties?
My thought is the current timeout granularity is too large and only
applies
to the full test execution. If a test knew that a timeoutFactor was to
be applied,
it could internally adjust the time dependent delays appropriately. e.g.
not every sleep(), await(), join() with timeouts would need the
timeoutFactor applied.
I don't quite get what you mean about the timeouts applied to sleeps,
awaits etc. Depending on the test some of these are delays (eg sleep
is usually used this way) because it may not be feasible (or even
possible) to coordinate the threads directly; while others (await,
wait etc) are actual timeouts - if they expire it is an error because
something appears to have gone wrong somewhere (of course this can be
wrong because the timeout was too short for a given situation).
As many of these tests have evolved along with the testing
infrastructure it isn't always very clear who has responsibility for
programming defensive timeouts. And many tests are designed to be run
stand-alone or under a test harness, where exceptions due to timeouts
are preferable to hangs.
Further, while we can add a scale factor for known retarding factors -
like Xcomp - there's no general way to assess the target machine
capability (# cores, speed) and load, as it may impact a given test.
And historically there has been a lack of resources to investigate and
solve these issues.
Cheers,
David
Before any test could be updated the information would need to be
available
from the test context.
Any feedback/pointers appreciated!
See
timeoutFactorArg
jtreg/src/share/classes/com/sun/javatest/regtest/Main.java
runOtherJVM()
jtreg/src/share/classes/com/sun/javatest/regtest/MainAction.java
maxTimeoutValue
jtreg/src/share/classes/com/sun/javatest/regtest/RegressionParameters.java
