7.20. cudaFuncAttributes Struct Reference

[Data types used by CUDA Runtime]

CUDA function attributes

Public Variables

int  binaryVersion
int  cacheModeCA
int  clusterDimMustBeSet
int  clusterSchedulingPolicyPreference
size_t  constSizeBytes
size_t  localSizeBytes
int  maxDynamicSharedSizeBytes
int  maxThreadsPerBlock
int  nonPortableClusterSizeAllowed
int  numRegs
int  preferredShmemCarveout
int  ptxVersion
int  requiredClusterWidth
int  reserved[16]
size_t  sharedSizeBytes


int cudaFuncAttributes::binaryVersion [inherited]

The binary architecture version for which the function was compiled. This value is the major binary version * 10 + the minor binary version, so a binary version 1.3 function would return the value 13.

int cudaFuncAttributes::cacheModeCA [inherited]

The attribute to indicate whether the function has been compiled with user specified option "-Xptxas --dlcm=ca" set.

int cudaFuncAttributes::clusterDimMustBeSet [inherited]

If this attribute is set, the kernel must launch with a valid cluster dimension specified.

int cudaFuncAttributes::clusterSchedulingPolicyPreference [inherited]

The block scheduling policy of a function. See cudaFuncSetAttribute

size_t cudaFuncAttributes::constSizeBytes [inherited]

The size in bytes of user-allocated constant memory required by this function.

size_t cudaFuncAttributes::localSizeBytes [inherited]

The size in bytes of local memory used by each thread of this function.

int cudaFuncAttributes::maxDynamicSharedSizeBytes [inherited]

The maximum size in bytes of dynamic shared memory per block for this function. Any launch must have a dynamic shared memory size smaller than this value.

int cudaFuncAttributes::maxThreadsPerBlock [inherited]

The maximum number of threads per block, beyond which a launch of the function would fail. This number depends on both the function and the device on which the function is currently loaded.

int cudaFuncAttributes::nonPortableClusterSizeAllowed [inherited]

Whether the function can be launched with non-portable cluster size. 1 is allowed, 0 is disallowed. A non-portable cluster size may only function on the specific SKUs the program is tested on. The launch might fail if the program is run on a different hardware platform.

CUDA API provides cudaOccupancyMaxActiveClusters to assist with checking whether the desired size can be launched on the current device.

Portable Cluster Size

A portable cluster size is guaranteed to be functional on all compute capabilities higher than the target compute capability. The portable cluster size for sm_90 is 8 blocks per cluster. This value may increase for future compute capabilities.

The specific hardware unit may support higher cluster sizes that’s not guaranteed to be portable. See cudaFuncSetAttribute

int cudaFuncAttributes::numRegs [inherited]

The number of registers used by each thread of this function.

int cudaFuncAttributes::preferredShmemCarveout [inherited]

On devices where the L1 cache and shared memory use the same hardware resources, this sets the shared memory carveout preference, in percent of the maximum shared memory. Refer to cudaDevAttrMaxSharedMemoryPerMultiprocessor. This is only a hint, and the driver can choose a different ratio if required to execute the function. See cudaFuncSetAttribute

int cudaFuncAttributes::ptxVersion [inherited]

The PTX virtual architecture version for which the function was compiled. This value is the major PTX version * 10 + the minor PTX version, so a PTX version 1.3 function would return the value 13.

int cudaFuncAttributes::requiredClusterWidth [inherited]

The required cluster width/height/depth in blocks. The values must either all be 0 or all be positive. The validity of the cluster dimensions is otherwise checked at launch time.

If the value is set during compile time, it cannot be set at runtime. Setting it at runtime should return cudaErrorNotPermitted. See cudaFuncSetAttribute

int cudaFuncAttributes::reserved[16] [inherited]

Reserved for future use.

size_t cudaFuncAttributes::sharedSizeBytes [inherited]

The size in bytes of statically-allocated shared memory per block required by this function. This does not include dynamically-allocated shared memory requested by the user at runtime.