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JDK-7146246 : G1: expose some of the -XX flags that drive which old regions to collect during mixed GCs

Details
Type:
Enhancement
Submit Date:
2012-02-16
Status:
Closed
Updated Date:
2013-07-28
Project Name:
JDK
Resolved Date:
2012-03-31
Component:
hotspot
OS:
generic
Sub-Component:
gc
CPU:
generic
Priority:
P3
Resolution:
Fixed
Affected Versions:
hs23
Fixed Versions:
hs24 (b55)

Related Reports
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Sub Tasks

Description
The heuristics that drive which old regions to collect during mixed GCs and which not, introduced by:

7132029: G1: mixed GC phase lasts for longer than it should

and maybe further fine-tuned by:

7146242: G1: alternative heuristic on deciding which old regions not to collect

introduced several develop -XX flags. It will be good to expose some of them to the users so that they can adjust the "space efficiency" vs. "pause times duration" trade-off to what they feel it's appropriate for them.

We should decide what the minimum number of flags is and make sure their names are reasonable.

                                    

Comments
PUBLIC COMMENTS

We're turning the following two into product params:

G1HeapWastePercent (previously called: G1OldReclaimableThresholdPercent)
G1MixedGCCountTarget (previous called: G1MaxMixedGCNum)

Also increased the default of the former from 1% to 5% and decreased the default for G1OldCSetRegionLiveThresholdPercent from 95% to 90%.
                                     
2012-03-21
EVALUATION

See Description / Public Comments.
                                     
2012-03-21
EVALUATION

http://hg.openjdk.java.net/hsx/hotspot-gc/hotspot/rev/21595f05bc93
                                     
2012-03-23
URL:   http://hg.openjdk.java.net/hsx/hsx24/hotspot/rev/39628b02a383
User:  amurillo
Date:  2013-07-26 22:45:30 +0000

                                     
2013-07-26



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