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Bug ID: JDK-7027529 CMS: retire CMSUseOldDefaults flag
JDK-7027529 : CMS: retire CMSUseOldDefaults flag

Details
Type:
Bug
Submit Date:
2011-03-15
Status:
Closed
Updated Date:
2011-05-25
Project Name:
JDK
Resolved Date:
2011-04-24
Component:
hotspot
OS:
generic
Sub-Component:
gc
CPU:
generic
Priority:
P3
Resolution:
Fixed
Affected Versions:
7
Fixed Versions:
hs21 (b05)

Related Reports
Backport:
Relates:

Sub Tasks

Description
The flag CMSUseOldDefaults was provided in JDK 6 FCS when there had been a bunch of
performance enhancing changes to the defualt settings for CMS vis-a-vis JDK 5.
The idea was that JDK 5 customers who were relying on the old defaults in JDK 5
would continue to get (roughly) the old behaviour if they used this flag when
they moved to JDK 6. In effect this was a jumbo flag that provided a bunch of
default settings. During the past few years we have not come across any customer
who needed to rely on that flag, and moreover the general experience has been
of improved CMS performance after changing these defaults to what they are today
in JDK 6.

In this CR, we are proposing to remove and retire the flag CMSUseOldDefaults.

This CR should be release-noted in JDK 7.

                                    

Comments
EVALUATION

We are rolling this change with the changeset for:-
    6896099 Integrate CMS heap ergo with default heap sizing ergo.
                                     
2011-03-15
SUGGESTED FIX

Remove the flag and the associated settings in JDK 7.
                                     
2011-03-15
EVALUATION

http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/dde920245681
                                     
2011-03-16
EVALUATION

http://hg.openjdk.java.net/jdk7/hotspot-rt/hotspot/rev/dde920245681
                                     
2011-03-21
EVALUATION

http://hg.openjdk.java.net/jdk7/hotspot-comp/hotspot/rev/dde920245681
                                     
2011-03-25



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