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

[David Holmes]

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
>