Module openj9.gpu

Package com.ibm.gpu

Class CUDAManager

java.lang.Object

com.ibm.gpu.CUDAManager

public final class CUDAManager
extends Object

This class contains information important to IBM GPU enabled functions.

Method Summary

Modifier and Type	Method	Description
int	acquireFreeDevice()	Look for the next free device and mark it as busy.
ArrayList<CUDADevice>	getCUDADevices()	Use this method to obtain a reference to an ArrayList containing references to all discovered CUDA devices.
int	getDefaultDevice()	Gets the ID of the default device, set to 0 by default.
CUDADevice	getDevice(int deviceId)	Get a reference to the CUDA device by means of its index (with 0 being the first).
int	getDeviceCount()	Identifies the number of available CUDA devices.
CUDADevice	getDeviceWithMostAvailableMemory()	Identifies the CUDA device that has the most memory available.
int	getDoubleThreshold()	Gets the minimum length of a double array that will be sorted using a GPU if enabled.
CUDADevice[]	getEnabledCUDADevices()	Use this method to return an array of enabled CUDA devices.
int	getFloatThreshold()	Gets the minimum length of a float array that will be sorted using a GPU if enabled.
long	getFreeMemoryForDevice(int deviceId)	Get the amount of free memory (in bytes) available for the provided CUDA device.
static CUDAManager	getInstance()	Deprecated. Use instance() instead.
int	getIntThreshold()	Gets the minimum length of an int array that will be sorted using a GPU if enabled.
int	getLongThreshold()	Gets the minimum length of a long array that will be sorted using a GPU if enabled.
int	getNextAvailableDevice()	Returns the next CUDA device that is available to run calculations on.
static String	getOutputHeader()	Get the header used to prefix all IBM GPU related output.
boolean	getVerboseGPUOutput()	Get the value of the verboseGPUOutput flag.
static String	getVersion()	Get the version of this class.
boolean	hasCUDASupport()	Use this method to identify if CUDA is supported on this machine and within this environment: returns true if the number of CUDA devices detected is greater than 0.
static CUDAManager	instance()	Return a CUDAManager instance.
boolean	isSortEnabledOnGPU()	This method provides a means to determine if sort is enabled to be used by any available CUDA device.
boolean	isSortEnforcedOnGPU()	This method provides a means to determine if sort is forced to be used by any available CUDA device.
void	printAllDeviceInfo()	Print information for each detected CUDA device.
void	releaseDevice(int deviceId)	Mark a device as being free; must be in a try finally block as we MUST release the handle regardless of whether or not a sort was successful.
void	setDefaultDevice(int deviceId)	Sets the default device to the given device ID.
void	setDevice(int deviceId)	Use this method to set the device to use for subsequent calls.
void	setVerboseGPU(boolean condition)	Set the value of the verboseGPUOutput flag.
static void	tearDown()	Deprecated. This method has no effect; it will be removed in a future version.

Methods declared in class java.lang.Object

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

Method Details

getInstance

@Deprecated
public static CUDAManager getInstance()
                               throws GPUConfigurationException,
SecurityException

Deprecated.

Use instance() instead.

Return a CUDAManager instance.

Returns:

a CUDAManager instance

Throws:

GPUConfigurationException - This exception is not actually thrown; use instance() instead.

SecurityException - If a security manager exists and the calling thread does not have permission to access the CUDAManager instance.

instance

public static CUDAManager instance()
                            throws SecurityException

Return a CUDAManager instance.

Returns:

a CUDAManager instance

Throws:

SecurityException - If a security manager exists and the calling thread does not have permission to access the CUDAManager instance.

getOutputHeader

public static String getOutputHeader()

Get the header used to prefix all IBM GPU related output.

Returns:

The header used for IBM GPU related output.

getVersion

public static String getVersion()

Get the version of this class.

Returns:

Returns the version of this class.

tearDown

@Deprecated
public static void tearDown()

Deprecated.

This method has no effect; it will be removed in a future version.

Performs cleanup on the CUDAManager class.

acquireFreeDevice

public int acquireFreeDevice()

Look for the next free device and mark it as busy.

Returns:

Returns the device ID of the next free device.

getCUDADevices

public ArrayList<CUDADevice> getCUDADevices()

Use this method to obtain a reference to an ArrayList containing references to all discovered CUDA devices.

Returns:

Returns an ArrayList containing all discovered CUDA devices - see CUDADevice for details.

getDefaultDevice

public int getDefaultDevice()

Gets the ID of the default device, set to 0 by default.

Returns:

Returns the device ID of the current default device.

getDevice

public CUDADevice getDevice(int deviceId)
                     throws GPUConfigurationException

Get a reference to the CUDA device by means of its index (with 0 being the first).

Parameters:

deviceId - The index of the device to retrieve (with 0 being the first).

Returns:

Returns a CUDA device at the specified index - see CUDADevice for details.

Throws:

GPUConfigurationException - Throws this exception if an invalid deviceId has been specified.

getDeviceCount

public int getDeviceCount()

Identifies the number of available CUDA devices.

Returns:

Returns how many CUDA devices have been detected.

getDeviceWithMostAvailableMemory

public CUDADevice getDeviceWithMostAvailableMemory()
                                            throws GPUConfigurationException

Identifies the CUDA device that has the most memory available.

Returns:

Returns a reference to the CUDA device with the most memory available.

Throws:

GPUConfigurationException - Throws this exception if an attempt was made to access an invalid device (no longer available).

getDoubleThreshold

public int getDoubleThreshold()

Gets the minimum length of a double array that will be sorted using a GPU if enabled.

Returns:

The minimum length of a double array that will be sorted using a GPU.

getEnabledCUDADevices

public CUDADevice[] getEnabledCUDADevices()

Use this method to return an array of enabled CUDA devices.

Returns:

Returns an array containing enabled CUDA devices - see CUDADevice for details.

getFloatThreshold

public int getFloatThreshold()

Gets the minimum length of a float array that will be sorted using a GPU if enabled.

Returns:

The minimum length of a float array that will be sorted using a GPU.

getFreeMemoryForDevice

public long getFreeMemoryForDevice(int deviceId)
                            throws GPUConfigurationException

Get the amount of free memory (in bytes) available for the provided CUDA device. Does not persistently change the current device.

Parameters:

deviceId - The index of the device to query (with 0 being the first).

Returns:

Returns the amount of free memory available.

Throws:

GPUConfigurationException - Throw this exception if cannot get free memory amount.

getIntThreshold

public int getIntThreshold()

Gets the minimum length of an int array that will be sorted using a GPU if enabled.

Returns:

The minimum length of an int array that will be sorted using a GPU.

getLongThreshold

public int getLongThreshold()

Gets the minimum length of a long array that will be sorted using a GPU if enabled.

Returns:

The minimum length of a long array that will be sorted using a GPU.

getNextAvailableDevice

public int getNextAvailableDevice()

Returns the next CUDA device that is available to run calculations on.

Returns:

-1 if there are no free devices, otherwise returns the ID of the free CUDA device.

getVerboseGPUOutput

public boolean getVerboseGPUOutput()

Get the value of the verboseGPUOutput flag.

Returns:

Whether or not verbose output should be produced.

hasCUDASupport

public boolean hasCUDASupport()

Use this method to identify if CUDA is supported on this machine and within this environment: returns true if the number of CUDA devices detected is greater than 0.

Returns:

Returns true if one or more CUDA devices have been detected.

isSortEnabledOnGPU

public boolean isSortEnabledOnGPU()

This method provides a means to determine if sort is enabled to be used by any available CUDA device.

Returns:

Returns true if GPU sort is enabled.

isSortEnforcedOnGPU

public boolean isSortEnforcedOnGPU()

This method provides a means to determine if sort is forced to be used by any available CUDA device.

Returns:

Returns true if GPU sort is forced.

printAllDeviceInfo

public void printAllDeviceInfo()

Print information for each detected CUDA device.

releaseDevice

public void releaseDevice(int deviceId)

Mark a device as being free; must be in a try finally block as we MUST release the handle regardless of whether or not a sort was successful.

Parameters:

deviceId - The device to be marked as free.

setDefaultDevice

public void setDefaultDevice(int deviceId)

Sets the default device to the given device ID.

Parameters:

deviceId - The new default device.

setDevice

public void setDevice(int deviceId)
               throws GPUConfigurationException

Use this method to set the device to use for subsequent calls.

Parameters:

deviceId - Set the default device ID to be this.

Throws:

GPUConfigurationException - Throws this exception if an invalid device number was specified.

setVerboseGPU

public void setVerboseGPU(boolean condition)

Set the value of the verboseGPUOutput flag. When this flag is true, GPU output will be produced.

Parameters:

condition - Whether or not verbose output should be produced.