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8232365: Implementation for JEP 363: Remove the Concurrent Mark Sweep (CMS) Garbage Collector

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Reviewed-by: kbarrett, tschatzl, erikj, coleenp, dholmes
This commit is contained in:
Leo Korinth 2019-11-13 11:37:29 +01:00
parent b8b88853a5
commit 1fc67ab002
239 changed files with 220 additions and 27246 deletions
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90
src/java.base/share/man/java.1
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@ -2975,70 +2975,6 @@ By default, this option is disabled and all pages are committed as the
application uses the heap space.
.RS
.RE
.TP
.B \f[CB]\-XX:+CMSClassUnloadingEnabled\f[R]
Enables class unloading when using the concurrent mark\-sweep (CMS)
garbage collector.
This option is enabled by default.
To disable class unloading for the CMS garbage collector, specify
\f[CB]\-XX:\-CMSClassUnloadingEnabled\f[R].
.RS
.RE
.TP
.B \f[CB]\-XX:CMSExpAvgFactor=\f[R]\f[I]percent\f[R]
Sets the percentage of time (0 to 100) used to weight the current sample
when computing exponential averages for the concurrent collection
statistics.
By default, the exponential averages factor is set to 25%.
The following example shows how to set the factor to 15%:
.RS
.RS
.PP
\f[CB]\-XX:CMSExpAvgFactor=15\f[R]
.RE
.RE
.TP
.B \f[CB]\-XX:CMSInitiatingOccupancyFraction=\f[R]\f[I]percent\f[R]
Sets the percentage of the old generation occupancy (0 to 100) at which
to start a CMS collection cycle.
The default value is set to \-1.
Any negative value (including the default) implies that the option
\f[CB]\-XX:CMSTriggerRatio\f[R] is used to define the value of the
initiating occupancy fraction.
.RS
.PP
The following example shows how to set the factor to 20%:
.RS
.PP
\f[CB]\-XX:CMSInitiatingOccupancyFraction=20\f[R]
.RE
.RE
.TP
.B \f[CB]\-XX:CMSIncrementalDutySafetyFactor=\f[R]\f[I]percent\f[R]
Sets the percentage (0 to 100) used to add conservatism when computing
the duty cycle.
The default value is 10.
.RS
.RE
.TP
.B \f[CB]\-XX:+CMSScavengeBeforeRemark\f[R]
Enables scavenging attempts before the CMS remark step.
By default, this option is disabled.
.RS
.RE
.TP
.B \f[CB]\-XX:CMSTriggerRatio=percent\f[R]
Sets the percentage (0 to 100) of the value specified by the option
\f[CB]\-XX:MinHeapFreeRatio\f[R] that\[aq]s allocated before a CMS
collection cycle commences.
The default value is set to 80%.
.RS
.PP
The following example shows how to set the occupancy fraction to 75%:
.RS
.PP
\f[CB]\-XX:CMSTriggerRatio=75\f[R]
.RE
.RE
.TP
.B \f[CB]\-XX:ConcGCThreads=\f[R]\f[I]threads\f[R]
@ -3070,7 +3006,6 @@ still performs GC when necessary.
Enables invoking of concurrent GC by using the \f[CB]System.gc()\f[R]
request.
This option is disabled by default and can be enabled only with the
deprecated \f[CB]\-XX:+UseConcMarkSweepGC\f[R] option and the
\f[CB]\-XX:+UseG1GC\f[R] option.
.RS
.RE
@ -3460,8 +3395,7 @@ amount of memory used for the Java heap for small heaps:
.B \f[CB]\-XX:MaxTenuringThreshold=\f[R]\f[I]threshold\f[R]
Sets the maximum tenuring threshold for use in adaptive GC sizing.
The largest value is 15.
The default value is 15 for the parallel (throughput) collector, and 6
for the CMS collector.
The default value is 15 for the parallel (throughput) collector.
.RS
.PP
The following example shows how to set the maximum tenuring threshold to
@ -3724,13 +3658,6 @@ See the \f[CB]\-XX:SurvivorRatio\f[R] option.
.RS
.RE
.TP
.B \f[CB]\-XX:+UseCMSInitiatingOccupancyOnly\f[R]
Enables the use of the occupancy value as the only criterion for
initiating the CMS collector.
By default, this option is disabled and other criteria may be used.
.RS
.RE
.TP
.B \f[CB]\-XX:+UseG1GC\f[R]
Enables the use of the garbage\-first (G1) garbage collector.
It\[aq]s a server\-style garbage collector, targeted for multiprocessor
@ -3975,21 +3902,6 @@ The replacement Unified Logging syntax is
See \f[B]Enable Logging with the JVM Unified Logging Framework\f[R].
.RE
.TP
.B \f[CB]\-XX:+UseConcMarkSweepGC\f[R]
Enables the use of the CMS garbage collector for the old generation.
CMS is an alternative to the default garbage collector (G1), which also
focuses on meeting application latency requirements.
By default, this option is disabled and the collector is selected
automatically based on the configuration of the machine and type of the
JVM.
The CMS garbage collector is deprecated.
.RS
.RE
.SH OBSOLETE JAVA OPTIONS
.PP
These \f[CB]java\f[R] options are still accepted but ignored, and a
warning is issued when they\[aq]re used.
.TP
.B \f[CB]\-XX:+UseMembar\f[R]
Enabled issuing membars on thread\-state transitions.
This option was disabled by default on all platforms except ARM servers,