RFR: 8232082: Log which shows disabling COOP should be tagged to gc+heap+coops
david.holmes at oracle.com
Thu Oct 10 06:13:25 UTC 2019
On 10/10/2019 3:26 pm, Yasumasa Suenaga wrote:
> Hi David,
> On 2019/10/10 13:58, David Holmes wrote:
>> Hi Yasumasa,
>> On 10/10/2019 12:34 pm, Yasumasa Suenaga wrote:
>>> Hi all,
>>> Please review this change:
>>> JBS: https://bugs.openjdk.java.net/browse/JDK-8232082
>>> webrev: http://cr.openjdk.java.net/~ysuenaga/JDK-8232082/webrev.00/
>>> Log message is tagged to "cds" when COOP is disabled by ergonomics
>>> due to heap size. This log has introduced in JDK-8226462.
>>> But it might occur outside of CDS. So it should be tagged to
>>> "gc+heap+coops" instead of "cds".
>> The logging wasn't put in to show the conditions under which the
>> ergonomics kicked in, it was put in to show CDS users that it had
>> kicked in.
> This message would be shown when CDS is disabled as below:
> $ java -XX:MaxRAM=192g -XX:MaxRAMPercentage=75 -XX:-UseSharedSpaces
> -Xlog:cds --version
> [0.015s][info][cds] UseCompressedOops and UseCompressedClassPointers
> have been disabled due to max heap 154618822656 > compressed oop heap
> 32178700288. Please check the setting of MaxRAMPercentage 75.00.
> openjdk 13 2019-09-17
> OpenJDK Runtime Environment (build 13+33)
> OpenJDK 64-Bit Server VM (build 13+33, mixed mode)
The Xlog:cds is independent of any use of CDS - part of the logging may
be to show that CDS is not being used.
> Also this message might be useful for all users.
> Thus I want to change this log tag.
As I said its fine to show it under other circumstances as well but this
was deemed of interest to people doing CDS logging so it should remain
enabled in that case.
>> So if you think it should be logged under additional conditions, that
>> is fine, but please do not replace the existing logging.
>> Unfortunately there is no nice way to log the same information under
>> multiple tags.
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