RFR: 8203491: [TESTBUG] Port heapdump tests into java
jini.george at oracle.com
Thu May 24 16:16:02 UTC 2018
My comments inline.
On 5/24/2018 12:09 AM, Leonid Mesnik wrote:
> I am not sure that JMapMetaspaceCore provides any additional coverage.
> The test just fill 64M of metaspace and then send signal to dump core.
> So I don't see how this test could improve coverage.
> I think that idea of original test was to fill PermGen like Heap to
> expand it as much as possible or it was just an analog of test
> OnOOMToFileMetaspace. While current test just fill highly limited
> metaspace. So number of classes seems to be not significantly larger
> then for current TestJmapCore.java test. From my point of view it would
> be make a sense to generate dump containing a lot of loaded classes or
> some very large classes.
> While current test looks pretty similar to existing TestJmapCore.java
> test. Please let me know if you see the test scenario when such test
> could be useful.
From what I can make out, EatMemory with -metaspace would create a lot
of loaded classes with GeneratedClassProducer. And this could provide
some good testing for writeClassDumpRecords() of HeapHprofBinWriter. Let
me know if you think I have overlooked something.
>> * You might want to increase the timeout factor for this test. The
>> test times out on my machine.
> I see that test finishes in 1 minute in our lab while. I see that it
> takes 30 seconds on 2CPU Oracle Linux VM with 2GB java heap. And test
> just fails with JDK-8176557 when I increase heap.
> How many time it takes on you machine? The timeoutFactor might be used
> for untypical environment/command-line options.
It took about 130 secs a couple of times. Don't know if it was an anomaly.
>> * You might want to consider removing the corefile and the heapdump
>> files after the test execution (in the cases where the test passes).
> The default jtreg retain policy in make files just removes all files in
> test directory for passed tests. The jtreg default test policy says
> "If -retain is not specified, only the files from the last test
> executed will be retained".
> So it should be not a problem in most of cases. While there is no way
> for user to retain core/heapdump files even if user wants to keeps them.
> However if it is the common rule for sa tests to delete such artifacts
> then I could remove heap/core dumps.
>> One suggestion is to check if /proc/sys/kernel/core_pattern has a line
>> starting with '|' and print a warning that a crash reporting tool
>> might be used (Something like in ClhsdbCDSCore.java). But it is just a
>> suggestion and you are free to ignore it. In due course, we could
>> include this test also as a part of the consolidation of SA's corefile
>> testing effort (https://bugs.openjdk.java.net/browse/JDK-8202297).
> I would prefer to left this improvement for JDK-8202297. I think good
> core dump processing/ulimit settings requires more efforts and testing
> and different version of Linux. (Might be even for Non-Oracle platforms).
> Also logic in test ClhsdbCDSCore.java is slightly different. It tries to
> get possible core location from hs_err file and print this hint of core
> file from hs_err doesn't exists. While printing this hint if core dumps
> are just completely disabled might just confuse users.
More information about the hotspot-runtime-dev