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Bug ID: JDK-6928059 G1: command line parameter renaming
JDK-6928059 : G1: command line parameter renaming

Details
Type:
Enhancement
Submit Date:
2010-02-19
Status:
Closed
Updated Date:
2011-03-08
Project Name:
JDK
Resolved Date:
2011-03-08
Component:
hotspot
OS:
generic
Sub-Component:
gc
CPU:
generic
Priority:
P3
Resolution:
Fixed
Affected Versions:
hs17,7
Fixed Versions:
hs17 (b11)

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Sub Tasks

Description
We would like to have consistency in the naming of the command line parameters in G1 in two ways: first, consistency in naming and second use standard (i.e., existing non-G1) parameters where appropriate. 

This CR will cover the renaming of all our current flags that are available in the product (i.e., product, diagnostic, and experimental flags) that we want to rename. Separate CRs will cover other G1 flag changes whose implementation will be a bit more involved (i.e., it will not be just a simple renaming).

General guidelines for the parameter naming:

- All G1-only parameters is prefixed with "G1"
- concurrent refinement is referred to as "ConcRefinement"
- concurrent marking is referred to as "ConcMark"
- A G1 heap region is referred to as "HeapRegion"
- switch type of flags (i.e., the switch a service on or off) will use the "Use" form and be prefixed with "G1", e.g., G1UseAdaptiveConcRefinement
- parameters that represent milliseconds are suffixed with "Millis"
- parameters that represent percentages are suffixed with "Percent"

The Public Comments on this CR will enumerate all flag changes (that will be covered by this and the other CRs), so that we can have them in one place.

                                    

Comments
PUBLIC COMMENTS

The flags that will be renamed as part of this CR are the following.

Simple renaming (done as part of this CR):

product:

G1AdaptiveConcRefine -> G1UseAdaptiveConcRefinement
G1ConcRefineGreenZone -> G1ConcRefinementGreenZone
G1ConcRefineRedZone -> G1ConcRefinementRedZone
G1ConcRefineServiceInterval -> G1ConcRefinementServiceIntervalMillis
G1ConcRefineThresholdStep -> G1ConcRefinementThresholdStep
G1ConcRefineYellowZone -> G1ConcRefinementYellowZone
G1ForgetfulMMUTracker -> G1UseFixedWindowMMUTracker
G1MinReservePercent -> G1ReservePercent
G1ParallelRSetThreads -> G1ConcRefinementThreads
G1RSUpdatePauseFractionPercent -> G1RSetUpdatingPauseTimePercent
G1SATBLogBufferSize -> G1SATBBufferSize

diagnostic:

G1PrintRegions -> G1PrintHeapRegions
G1SummarizeConcurrentMark -> G1SummarizeConcMark
G1TraceConcurrentRefinement -> G1TraceConcRefinement

experimental:

G1ParallelRSetScanningEnabled -> G1UseParallelRSetScanning
G1ParallelRSetUpdatingEnabled -> G1UseParallelRSetUpdating

Others (done as part of this CR):

G1ExpandByPercentOfAvailable : make it experimental until we decide the G1 heap resizing policy

G1SATBProcessCompletedThreshold : turn into a develop flag

G1UseScanOnlyPrefix : we're in the process of removing the scan-only prefix (see 6871109), so turn it into a develop flag meanwhile

G1UseSurvivorSpaces : remove it and have survivors constantly enabled (but they can be disabled in the standard way: MaxTenuringThreshold=0, etc.)

Use of existing parameters (done as part of other CRs):

G1MarkStackSize -> rename to MarkStackSize (and make CMSMarkStackSize an alias of MarkStackSize) (CR 6928081)

G1ParallelGCAllocBufferSize -> YoungPLABSize and OldPLABSize (we'll do this in the context of CR 6818524)

G1SteadyStateUsed / G1SteadyStateUsedDelta -> remove and use InitiatingHeapOccupancyPercent (CR 6928073)

ParallelMarkingThreads -> rename ConcGCThreads (and make ParallelCMSThreads an alias of ConcGCThreads) (CR 6928081)

G1YoungGenSize -> remove and use NewSize / MaxNewSize / -Xmn / UseAdaptiveSizePolicy (CR 6928065)
                                     
2010-02-19
EVALUATION

See Comments.
                                     
2010-02-19
EVALUATION

ChangeSet=http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/b81f3572f355,ChangeRequest=6928059
                                     
2010-02-24



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