cuda.bindings._v2.driver.mem_discard_batch_async#

cuda.bindings._v2.driver.mem_discard_batch_async( intptr_t dptrs, intptr_t sizes, size_t count, unsigned long long flags, intptr_t h_stream, )#

Performs a batch of memory discards asynchronously.

Performs a batch of memory discards. The batch as a whole executes in stream order but operations within a batch are not guaranteed to execute in any specific order. All devices in the system must have a non-zero value for the device attribute CU_DEVICE_ATTRIBUTE_CONCURRENT_MANAGED_ACCESS otherwise the API will return an error. Discarding a memory range informs the driver that the contents of that range are no longer useful. Discarding memory ranges allows the driver to optimize certain data migrations and can also help reduce memory pressure. This operation can be undone on any part of the range by either writing to it or prefetching it via cuMemPrefetchAsync or cuMemPrefetchBatchAsync. Reading from a discarded range, without a subsequent write or prefetch to that part of the range, will return an indeterminate value. Note that any reads, writes or prefetches to any part of the memory range that occur simultaneously with the discard operation result in undefined behavior. Performs memory discard on address ranges specified in dptrs and sizes. Both arrays must be of the same length as specified by count. Each memory range specified must refer to managed memory allocated via cuMemAllocManaged or declared via managed variables or it may also refer to system-allocated memory when all devices have a non-zero value for CU_DEVICE_ATTRIBUTE_PAGEABLE_MEMORY_ACCESS.

Parameters:

dptrs (intptr_t) – Array of pointers to be discarded.
sizes (intptr_t) – Array of sizes for memory discard operations.
count (size_t) – Size of dptrs and sizes arrays.
flags (unsigned long long) – Flags reserved for future use. Must be zero.
h_stream (intptr_t) – The stream to enqueue the operations in. Must not be legacy NULL stream.