RFR(S): 8071822: [TEST_BUG] Adapt collectorPolicy internal tests to support 64K pages

Jon Masamitsu jon.masamitsu at oracle.com
Tue Feb 17 18:56:50 UTC 2015


On 2/16/15 8:33 AM, Lindenmaier, Goetz wrote:
>
> Hi Jon,
>
> thanks for looking at this change!
>
> It's not that easy as  just aligning to vm_page_size, but I can use
>
> CollectorPolicy::compute_heap_alignment():
>
> http://cr.openjdk.java.net/~goetz/webrevs/8071822-jtregColPol/webrev.02/ 
> <http://cr.openjdk.java.net/%7Egoetz/webrevs/8071822-jtregColPol/webrev.02/>
>

Please revert to the original order of these lines unless it
makes a difference.

  990     set_basic_flag_values();
  991     flag_value = 30 * M;


Could you define a variable to hold the heap alignment?

size_t heap_alignment = CollectorPolicy::compute_heap_alignment()

just to make it a little more readable.

Should the 30*M be aligned?

What is the 20*m?  Could you assign it to a variable with a descriptive
name?

Jon
>
> Best regards,
>
> Goetz.
>
> *From:*hotspot-gc-dev [mailto:hotspot-gc-dev-bounces at openjdk.java.net] 
> *On Behalf Of * Jon Masamitsu
> *Sent:* Donnerstag, 12. Februar 2015 00:35
> *To:* hotspot-gc-dev at openjdk.java.net
> *Subject:* Re: RFR(S): 8071822: [TEST_BUG] Adapt collectorPolicy 
> internal tests to support 64K pages
>
> Goetz,
>
> Could you have used page alignment to determine the
> new expected sizes?
>
> For example, instead of
>
>   987     // Calculate what we expect the flag to be.
>   988     flag_value = adapted_InitialHeapSize - MaxNewSize;
>   989     verify_old_initial(flag_value);
>
> expected_old_initial = align_size_up(flag_value, os::vm_page_size())
> verify_old_initial(expected_old_initial)
>
> Jon
>
> On 2/10/2015 7:43 AM, Lindenmaier, Goetz wrote:
>
>     Hi,
>
>     could someone please have a look at this change?
>
>     It's really not that big.
>
>     GC-folks maybe?
>
>     Thanks,
>
>     Goetz.
>
>     *From:*Lindenmaier, Goetz
>     *Sent:* Freitag, 30. Januar 2015 10:36
>     *To:* hotspot-dev Source Developers
>     *Subject:* RFR(S): 8071822: [TEST_BUG] Adapt collectorPolicy
>     internal tests to support 64K pages
>
>     Hi,
>
>     this fixes a final problem with 64-bit page size in the jtreg tests.
>
>     It addresses the internal VM tests of the collector policies.
>
>     Those tests set a row of fixed flag values, and one special value
>     to test.
>
>     Then they call the heap ergonomics and check the expected result
>     of the
>
>     special value.
>
>     With 64K page size, the heap ergonomics adapt more values,
>     breaking the tests.
>
>     Wrt. the adapted flag values the tests are correct though.
>
>     This change makes the expected values depend on the adapted flags,
>     and the
>
>     tests pass. They only depend on adapted flags that are not subject
>     of the
>
>     corresponding test.
>
>     Please review this test.  I please need a sponsor.
>
>     http://cr.openjdk.java.net/~goetz/webrevs/8071822-jtregColPol/webrev.01/
>     <http://cr.openjdk.java.net/%7Egoetz/webrevs/8071822-jtregColPol/webrev.01/src/share/vm/memory/collectorPolicy.cpp.udiff.html>
>
>
>     https://bugs.openjdk.java.net/browse/JDK-8071822
>
>     Best regards,
>
>       Goetz.
>

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