RFR(S): 8206998: [test] runtime/ElfDecoder/TestElfDirectRead.java requires longer timeout on ppc64
volker.simonis at gmail.com
Wed Jul 11 07:34:32 UTC 2018
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.
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:
>> can I please get a review for the following test-only change:
>> 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:
> Need to verify this with the jtreg folk: jtreg-use at openjdk.java.net
>> Thank you and best regards,
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