Package org.openjdk.jmc.flightrecorder.rules.jdk.memory

Class GcInvertedParallelismRule

java.lang.Object

org.openjdk.jmc.flightrecorder.rules.jdk.memory.GcInvertedParallelismRule

All Implemented Interfaces:

IRule

public class GcInvertedParallelismRule
extends Object
implements IRule

Rule that checks for "Inverted Parallelism", as described by the Garbagecat GC log analysis tool. Checks if the parallel collection performance is less than serial (single-threaded). See: https://github.com/mgm3746/garbagecat/blob/main/src/main/java/org/eclipselabs/garbagecat/util/jdk/JdkMath.java#L365

Field Summary

Fields

Modifier and Type	Field	Description
static final TypedResult<org.openjdk.jmc.common.unit.IQuantity>	GC_CPU_TIME_EVENT_COUNT
static final TypedResult<Long>	INVERTED_PARALLELISM_COUNT

Constructor Summary

Constructors

Constructor	Description
GcInvertedParallelismRule()

Method Summary

Modifier and Type	Method	Description
static int	calcParallelism(long timeUser, long timeSys, long timeReal)	Calculate parallelism, the ratio of user + sys to wall (real) time.
RunnableFuture<IResult>	createEvaluation(org.openjdk.jmc.common.item.IItemCollection items, org.openjdk.jmc.common.util.IPreferenceValueProvider valueProvider, IResultValueProvider resultProvider)
Collection<org.openjdk.jmc.common.util.TypedPreference<?>>	getConfigurationAttributes()
String	getId()
String	getName()
Map<String,RulesToolkit.EventAvailability>	getRequiredEvents()
Collection<TypedResult<?>>	getResults()
String	getTopic()
static boolean	isInvertedParallelism(int parallelism)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

GC_CPU_TIME_EVENT_COUNT

public static final TypedResult<org.openjdk.jmc.common.unit.IQuantity> GC_CPU_TIME_EVENT_COUNT

INVERTED_PARALLELISM_COUNT

public static final TypedResult<Long> INVERTED_PARALLELISM_COUNT

Constructor Details

GcInvertedParallelismRule

public GcInvertedParallelismRule()

Method Details

createEvaluation

public RunnableFuture<IResult> createEvaluation(org.openjdk.jmc.common.item.IItemCollection items,
 org.openjdk.jmc.common.util.IPreferenceValueProvider valueProvider,
 IResultValueProvider resultProvider)

Specified by:

createEvaluation in interface IRule

calcParallelism

public static int calcParallelism(long timeUser,
 long timeSys,
 long timeReal)

Calculate parallelism, the ratio of user + sys to wall (real) time.

Parameters:

timeUser - The user (non-kernel) time.

timeSys - The sys (kernel) time.

timeReal - The wall (clock) time.

Returns:

Percent user:real time rounded up the the nearest whole number.

isInvertedParallelism

public static boolean isInvertedParallelism(int parallelism)

Parameters:

parallelism - The parallelism percent (ratio or user to wall (real time).

Returns:

True if the parallelism is "inverted", false otherwise. Inverted parallelism is less than 100. In other words, the parallel collection performance is less than serial (single-threaded).

getConfigurationAttributes

public Collection<org.openjdk.jmc.common.util.TypedPreference<?>> getConfigurationAttributes()

Specified by:

getConfigurationAttributes in interface IRule

getId

public String getId()

Specified by:

getId in interface IRule

getName

public String getName()

Specified by:

getName in interface IRule

getTopic

public String getTopic()

Specified by:

getTopic in interface IRule

getRequiredEvents

public Map<String,RulesToolkit.EventAvailability> getRequiredEvents()

Specified by:

getRequiredEvents in interface IRule

getResults

public Collection<TypedResult<?>> getResults()

Specified by:

getResults in interface IRule