[11] RFR(S): 8206998: [test] runtime/ElfDecoder/TestElfDirectRead.java requires longer timeout on ppc64

Volker Simonis volker.simonis at gmail.com
Wed Jul 11 07:34:32 UTC 2018


Hi David,

so it obviously works and as Goetz mentioned there are already other,
existing tests which use this feature.

Do you want me to get a formal review which confirms this from
somebody from the JTreg team?

I've CC-ed jtreg-use and Jonathan in the hope that they can confirm this.

Regards,
Volker

On Tue, Jul 10, 2018 at 11:24 PM, David Holmes <david.holmes at oracle.com> wrote:
> Hi Volker,
>
> On 11/07/2018 3:52 AM, Volker Simonis wrote:
>>
>> Hi,
>>
>> can I please get a review for the following test-only change:
>>
>> http://cr.openjdk.java.net/~simonis/webrevs/2018/8206998/
>> https://bugs.openjdk.java.net/browse/JDK-8206998
>>
>> The problem is that the test runtime/ElfDecoder/TestElfDirectRead.java
>> intentionally disables caching of Elf sections during symbol lookup
>> with WhiteBox.disableElfSectionCache(). On platforms which do not use
>> file descriptors instead of plain function pointers this slows down
>> the lookup just a little bit, because all the symbols from an Elf file
>> are still read consecutively after one 'fseek()' call. But on
>> platforms with file descriptors like ppc64 big-endian, we get two
>> 'fseek()' calls for each symbol read from the Elf file because reading
>> the file descriptor table is nested inside the loop which reads the
>> symbols. This really trashes the I/O system and considerable slows
>> down the test, so we need an extra long timeout setting.
>>
>> The fix is trivial - simply provide two test versions (i.e. comments):
>> the first one for all Linux flavors which are not ppc64 and a second,
>> new one for Linux/ppc64 which simply has a bigger timeout.
>
>
> I was not aware that this was a valid way of defining a test! This suggests
> there can only be one "leading comment" per "defining file:
>
> http://openjdk.java.net/jtreg/tag-spec.html
>
> Need to verify this with the jtreg folk: jtreg-use at openjdk.java.net
>
> Thanks,
> David
>
>
>> Thank you and best regards,
>> Volker
>>
>


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