RFR (XXS): 8143220: Fix documentation of InitiatingHeapOccupancyPercent
ecki at zusammenkunft.net
ecki at zusammenkunft.net
Fri Feb 5 14:49:34 UTC 2016
Hello,
Isnt this used for CMS also? Should it mention OccupancyOnly option? What is meant with "at the end of next GC"?
Gruss
Bernd
--
http://bernd.eckenfels.net
-----Original Message-----
From: "kirk at kodewerk.com" <kirk at kodewerk.com>
To: Thomas Schatzl <thomas.schatzl at oracle.com>
Cc: hotspot-gc-dev at openjdk.java.net
Sent: Fr., 05 Feb. 2016 15:05
Subject: Re: RFR (XXS): 8143220: Fix documentation of InitiatingHeapOccupancyPercent
Hi,
Does this represent a change in behavior aside from it being adaptive. I ask because I understand this comment to suggest that IHOP is no longer based on total heap occupancy but instead just on tenured occupancy.
Sorry but aside from that I find the comment some what confusing. Can you confirm that what I’ve written is what is meant.
"The percent occupancy (IHOP) of old generational heap after which a concurrent mark cycle with be initiated with the next GC. The value maybe changed if adaptive IHOP is enabled. Otherwise the value remains constant. Setting a value of 0 will result in frequent concurrent marking cycles. (G1 collector only)”
+ "Percentage of the old gen heap occupancy to start a concurrent " \
+ "GC cycle (IHOP) at the end of the next GC. " \
+ "If the IHOP value is determined adaptively by the collector, " \
+ "this value is used as the initial value while there is not " \
+ "enough information to do the adaptive sizing. Otherwise this " \
+ "value is fixed. In this case, setting a value of 0 causes " \
+ "concurrent marking to run as much as possible. " \
+ "Used in the G1 collector only.")
Kind regards,
Kirk
> On Feb 5, 2016, at 11:52 AM, Thomas Schatzl <thomas.schatzl at oracle.com> wrote:
>
> Hi all,
>
> can I have reviews for this change to the documentation of the
> InitiatingHeapOccupancyPercent global? I think due to recent changes
> to the behavior it is warranted that the (internal) documentation
> reflects it.
>
> Other suggestions for the text welcome.
>
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8143220
> Webrev:
> http://cr.openjdk.java.net/~tschatzl/8143220/webrev/
> Testing:
> local compilation
>
> Thanks,
> Thomas
>
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