RFR: Backport 8195115: G1 Old Gen MemoryPool CollectionUsage.used values don't reflect mixed GC results

[Hohensee, Paul]

Please review a backport to jdk8u.

Bug: https://bugs.openjdk.java.net/browse/JDK-8195115
Webrev: http://cr.openjdk.java.net/~phh/8195115/webrev.05/
JDK11 patch: http://hg.openjdk.java.net/jdk/jdk/rev/5d3c5af82654

The backport is slightly different from the JDK11 patch due to G1 refactoring, hence my request for new review. I’ll ask for jdk8u approval once the backport is reviewed.

I backported two jtreg tests from JDK11, which pass. Also, all the hotspot gc jtreg tests pass as well as they do for jdk8u-dev.

There was a CSR involved, https://bugs.openjdk.java.net/browse/JDK-8196719. Does that have to be re-approved for jdk8u as well, and if so, what’s the process?

Thanks,

Paul

[JC Beyler]

Hi Paul,

The biggest thing I saw in this RFR was that the flags for the test:
http://cr.openjdk.java.net/~phh/8195115/webrev.05/test/gc/g1/mixedgc/TestOldGenCollectionUsage.java.html

were changed it seems:
- the @requires are different for the backport (you accept null for JDK8
for GC and also removed the @requires vm.opt.MaxGCPauseMillis == "null")
- the @run flags are different (-Xms/Xmx are 14m for the backport; they
were 12 originally; there is a comment below in the backport saying this
requires normally 12m though you ask for 14 in the @run)

What are the reasons for these differences?

Apart from that, the backport seemed ok but I'm not that well versed in the
GC changes :)
Jc

Post by Hohensee, Paul
Please review a backport to jdk8u.
Bug: https://bugs.openjdk.java.net/browse/JDK-8195115
Webrev: http://cr.openjdk.java.net/~phh/8195115/webrev.05/
JDK11 patch: http://hg.openjdk.java.net/jdk/jdk/rev/5d3c5af82654
The backport is slightly different from the JDK11 patch due to G1
refactoring, hence my request for new review. I’ll ask for jdk8u approval
once the backport is reviewed.
I backported two jtreg tests from JDK11, which pass. Also, all the hotspot
gc jtreg tests pass as well as they do for jdk8u-dev.
There was a CSR involved, https://bugs.openjdk.java.net/browse/JDK-8196719.
Does that have to be re-approved for jdk8u as well, and if so, what’s the
process?
Thanks,
Paul

[Thomas Schatzl]

Hi Paul,

Post by Hohensee, Paul
Please review a backport to jdk8u.
Bug: https://bugs.openjdk.java.net/browse/JDK-8195115
Webrev: http://cr.openjdk.java.net/~phh/8195115/webrev.05/
JDK11 patch: http://hg.openjdk.java.net/jdk/jdk/rev/5d3c5af82654
The backport is slightly different from the JDK11 patch due to G1
refactoring, hence my request for new review. I’ll ask for jdk8u
approval once the backport is reviewed.
I backported two jtreg tests from JDK11, which pass. Also, all the
hotspot gc jtreg tests pass as well as they do for jdk8u-dev.

I think the backport is good. Others need to decide whether this change
is worth backporting.

Post by Hohensee, Paul
There was a CSR involved,
https://bugs.openjdk.java.net/browse/JDK-8196719. Does that have to
be re-approved for jdk8u as well, and if so, what’s the process?

CC'ed Joe Darcy as I am not sure either.

Thanks,
Thomas