Is kernel memory allocation thread-safe?

Accelerated Computing CUDA CUDA Programming and Performance
1

Do I need to lock calls like “malloc” or “new” inside the kernel?

2

The programming guide doesn’t mention anything about locking, and given that there really is no simple “locking” construct in CUDA to begin with, I would assume that device-side memory allocation is threadsafe. (I wonder if they use atomics to achieve this, or a segmented heap…) It even says that you can pass the pointers between threads, and free() from a different thread as long as you don’t double-free a pointer.

3

Thanks for your reply. I also found that the the allocation fails if I just try to allocate a moderate size (starting to fail at ~10MB for just a single thread single block kernel, in GTX480). Anyone knows if this total size is configurable?

4

The size of the device memory heap is configurable through cudaDeviceSetLimit.