From f37b05ba6f56c7927f61f9664f9d01383b95357b Mon Sep 17 00:00:00 2001 From: dmitripivkine Date: Mon, 16 Oct 2017 13:34:56 -0400 Subject: [PATCH] Remove obsolete CommandLineOptions.html This collection of GC related options is obsolete (last time was updated for 2.4). There is a different (better) way to provide description for command lime options now. Signed-off-by: dmitripivkine --- runtime/gc_doc/CommandLineOptions.html | 583 ------------------------- 1 file changed, 583 deletions(-) delete mode 100644 runtime/gc_doc/CommandLineOptions.html diff --git a/runtime/gc_doc/CommandLineOptions.html b/runtime/gc_doc/CommandLineOptions.html deleted file mode 100644 index e5a23382549..00000000000 --- a/runtime/gc_doc/CommandLineOptions.html +++ /dev/null @@ -1,583 +0,0 @@ - - - - - Modron Garbage Collection Options - - - - -

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Modron Garbage Collection Options

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-NOTE: -Xgc: options are private, and subject to change at any -point in the future. -

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Option parameter key

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<value>integer value
percentinteger value in the range of 0--100 (inclusive)
ageinteger value in the range of 1--14 (inclusive)
timeinteger value (in milliseconds)
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General Garbage Collection Options

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OptionEffect
-Xgcpolicy:<option>optthruput Flat heap (no scavenger, no concurrent -mark)
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optavgpause Concurrent mark
gencon Scavenger, concurrent mark
subpool Subpool allocator, no scavenger, no -concurrent mark. Only AIX, and S390.
-Xmx<value>Memory maximum (Xmx >= Xms)
-scavenger enabled: minimum size 4 kilobytes on 32 bit architectures, 8 -kilobytes on 64 bit architectures
-scavenger disabled: minimum size 4 kilobytes on 32 bit architectures, 8 -kilobytes on 64 bit architectures
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-XresmanEnable resource managed support
-Xmdx<value>Default memory space maximum size. Xmdx <= Xmx. Ignored if --Xresman not entered.
-Xms<value>Initial memory size
-scavenger enabled: minimum size 4 kilobytes on 32 bit architectures, 8 -kilobytes on 64 bit architectures (Xms >= Xmn + Xmo)
-scavenger disabled: minimum size 4 kilobytes on 32 bit architectures, 8 -kilobytes on 64 bit architectures (Xms >= Xmo)
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-Xmos<value>Initial old space size, minimum size 512 bytes on 32 bit -architectures, 2048 bytes on 64 bit architectures
-Xmox<value>Maximum old space size
-Xmo<value>Set both Xmos and Xmox - note that attempting to set -Xmo and --Xmos, or -Xmo and -Xmox will be rejected
-Xmns<value>Initial new space size, minimum size 1024 bytes on 32 bit -architectures, 4096 bytes on 64 bit architectures
-scavenger disabled: ignored
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-Xmnx<value>Maximum new space size
-scavenger disabled: ignored
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-Xmn<value>Set both Xmns and Xmox - note that attempting to set -Xmn and --Xmns, or --Xmn and -Xmnx will be rejected
-scavenger disabled: ignored
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-Xmca<value>RAM class segment increment
-Xmco<value>ROM class segment increment
-Xmoi<value>Old space increment. When 0 no old space expansion possible.
-Xmine<value>Heap expansion minimum size
-Xmaxe<value>Heap expansion maximum size
-Xminf<value>Minimum heap percentage free after a garbage collection
-Xmaxf<value>Maximum heap percentage free after a garbage collection
-XlpEnable large page support
-XloaEnable large object area support (default)
-XnoloaDisable large object area support , all objects -are allocated in -SOA
-Xloainitial<value>A floating point value between 0 and 0.95, which specifies -the initial percentage  tenure space allocated to the LOA. -The default is 0.05, or 5%.
-Xloamaximum<value>A floating point value between 0 and 0.95, which -specifies the maximum percentage of  tenure space allocated to the -LOA. The default is 0.5, or 50%.
-Xgcthreads<value>Number of threads used for garbage collection - must -be > 0
-Xgcworkpackets<value>Number of workpackets used during marking - will be rounded -down to be a multiple of 5 and at least 20
-XnoclassgcDisable dynamic class unloading
-XclassgcDynamic class unloading only on class loader changes (default)
-XalwaysclassgcAlways perform dynamic class unloading checks during global -collection
-XenablestringconstantgcCollect strings from the interned string table
-XdisablestringconstantgcNever collect strings from the interned string table
-XenableexcessivegcThrow out-of-memory if excessive time is spent in GC (default)
-XdisableexcessivegcDo not throw out-of-memory if excessive time is spent in GC
-Xsoftrefthreshold<value>Number of GC's after which a soft reference will be cleared -if  its referent has not been marked.  The default is 32,.
-Xgc:<option>,<option>,... 
   tlhInitialSize=<value>Starting TLH size for threads
   tlhMinimumSize=<value>Minimum size to be a candidate for the free list (minimum 512 -bytes on 32 bit architectures, 1024 on 64 bit architectures)
   tlhMaximumSize=<value>Maximum allowable TLH size for a Thread
   tlhIncrementSize=<value>Size a TLH request increases after a successful refresh
   versionDump internal GC version information
   batchClearTLHEnable batch clear TLH
   jniArrayCacheMax=<value>Maximum size of a JNI cached array (used for copying on -getArrayElements type operations; the cache depth is 1).
-value= unlimited or >= 0; 0 disables the array cache
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   finInc=<value>Finalize list size increment
   finMax=<value>Finalize list size maximum
   finInterval=<time>Time between objects processed for finalization.
-time=nodelay or >= 0; 0 equivalent of a yield()
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   disablesubpoollargeheap Useful for configurations with not very high heap free -percentage. Only makes sense with subpool policy.
   microFragmentationDetection Detects heap fragmentation on sub-minimumFreeEntry size -(512bytes). Works only with subpool policy.
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Scavenger Options

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OptionEffect
-Xmr<value>Remembered set size
-Xmrx<value>Remembered set maximum size
-Xgc:<option>,<option>,... 
   scavengeEnable the scavenger
   noScavengeDisable the scavenger (write barrier checks will still occur -in the VM)
   failedTenureThreshold=<value>Maximum number of bytes that can fail tenuring before a -global GC will be triggered in place of the next scavenge (default is -none)
   maxScavengeBeforeGlobal=<value>Number of scavenges prior to a global garbage collect being -invoked (default is none)
   adaptiveTenureEnable adaptive tenuring (default)
   noAdaptiveTenureDisable adaptive tenuring - no tenure age adjustments will -occur
   tenureAge=<value>Age at which an object should be tenured. Default is 10.
-All objects are allocated with an age of 0. For every scavenge, a -surviving objects age is increased by 1. If the age of the object hits -the tenure threshold, it is copied to old space instead of the survivor -semi space.
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   scvth=<percent>High threshold of new space used after a scavenge to decrease -the tenure age by 1. Default is 30
   scvtl=<percent>Low threshold of a new space used after a scavenge to -increase the tenure age by 1. Default is 10
   tiltedScavengeEnable tilted scavenger (default)
   debugTiltedScavengeEnable tracing in tilted scavenger (default disabled)
   noTiltedScavengeDisable tilted scavenger
   tiltedScavengeMinimumRatio=<percent>The minimum ratio the survivor space size will have with -respect to the total new space size (used in conjunction with -tiltedScavenge). Valid percentages are 1-99.
   dynamicNewSpaceSizingEnable dynamic new space sizing (default)
   noDynamicNewSpaceSizingDisable dynamic new space sizing
   debugDynamicNewSpaceSizingEnable tracing in dynamic new space sizing (default disabled)
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Compact Options

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OptionEffect
-XnocompactexplicitgcDo not compact on system garbage collects. Compaction will -take place on global garabage collections if -Xcompactgc specified or -compactrion triggers met.
-XcompactexplicitgcCompact on all system garbage collect. Compaction will take -place on global garabage collections if -Xcompactgc specified or -compactrion triggers met.
-XcompactgcCompact on all garbage collect (system and global).
-XnocompactgcDisable compaction on all garnage collections (system or -global).
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Concurrent Options

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OptionEffect
-Xgc:<option>,<option>,... 
   concurrentMarkEnable concurrent mark (default disabled) (DEPRECATED? - this -will depend on what the policy names really mean in the end)
   concurrentRASChecksEnable concurrent RAS checks (default disabled)
-Xconcurrentbackground<value>The number of low priority background  threads attached -to assist the mutator threads in concurrent mark.  The default is -1.
-Xconcurrentlevel<value>The allocation "tax" rate, i.e the ratio between the amount -of heap allocated and the amount of heap marked.  The default is 8.
-Xconmeter:<option>soa Meter SOA -usage; only allocations in the SOA are taxed. 
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loa - Meter LOA usage; only allocations in the LOA are -taxed.
dynamic  The -collector dynamically determines which area to meter based on which -area is being exhausted first, be it the SOA or the LOA, and applies -the allocation tax accordingly.
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Trace GC Options (Xtgc:)

-These traces are similar to those provided by Sovereign's -Xtgc option -(for more information, see here).
-Format -Xtgc:<option>,<option>,... - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
OptionEffect
backtraceBefore a garbage collection, a single line is printed -containing the name of the master thread for garbage collection, as -well as the value of the osThread slot in its J9VMThread structure
compactionPrints extra information showing the relative time spent by -threads in the move and fixup phases of compaction
concurrentPrints extra information showing the activity of the -concurrent mark background thread
dumpSimilar to terse, prints a line of output for every free -chunk in the system, including dark matter (free chunks that are not on -the free list for some reason, usually because they are too small). -Each line contains the base address and the size in bytes of the chunk. -If the chunk is followed in the heap by an object, the size and class -name of the object is also printed.
freeListBefore a garbage collection, prints information about the -free list and allocation statistics since the last GC. Prints the -number of items on the free list, including "deferred" entries (with -the scavenger, the unused semispace is a deferred free list entry). For -TLH and non-TLH allocations, prints the total number of allocations, -the average allocation size, and the total number of bytes discarded in -during allocation. For non-TLH allocations, also included is the -average number of entries that were searched before a sufficiently -large entry was found.
parallelProduces statistics on the activity of the parallel threads -during the mark and sweep phases of a global GC.
referencesPrints extra information every time a reference object is -enqueued for finalisation, showing the reference type, reference -address, and referent address
scavengerPrints extra information following each scavenger collection. -A histogram is produced showing the number of instances of each class -(and their relative ages) present in the survivor space. The space is -linearly walked to achieve this.
terseDumps the contents of the entire heap before and after a -garbage collection. For each object or free chunk in the heap, a line -of trace output is produced. Each line contains the base address, "a" -if it is an allocated object and "f" if it is a free chunk, the size of -the chunk in bytes, and if it is an object, its class name.
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Deprecated Options

-The following options have been removed and replaced with new values. -

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