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JDK-6329603 : CMS: +CMSClassUnloadingEnabled and +CMSPermGenSweepingEnabled by default

Details
Type:
Enhancement
Submit Date:
2005-09-27
Status:
Closed
Updated Date:
2014-09-02
Project Name:
JDK
Resolved Date:
2014-09-02
Component:
hotspot
OS:
generic
Sub-Component:
gc
CPU:
generic
Priority:
P3
Resolution:
Won't Fix
Affected Versions:
6
Fixed Versions:

Related Reports
Relates:
Relates:

Sub Tasks

Description
Customers who care to reduce pause times further would turn off
class unloading as needed, knowing the needs of their applications.

We need to do refworkload/alacrity measurements to understand and
document the performance impact if any from such a switch.

                                    

Comments
CMSClassUnloadingEnabled is already default, and there is no CMSPermGenSweepingEnabled switch any more after JDK8 perm gen changes.
                                     
2014-09-02
EVALUATION

This will need more work, since enabling perm gen collection
appears to adversely impact remark times by more than we had
anticipated. That investigation is formally deferred to Dolphin.
                                     
2005-10-27
SUGGESTED FIX

change the default setting of these two flags in glogals.hpp.
                                     
2005-09-27
EVALUATION

Should do by b55 if possible.
                                     
2005-09-27



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