What does the 'zu bytes' mean?

Accelerated Computing CUDA CUDA Programming and Performance
1

Hi, I’m doing some work with CUDA. I run the deviceQuery.exe to get device information.
But what does the ‘zu bytes’ mean in the chart?

Device 0: "GeForce 940MX"
  CUDA Driver Version / Runtime Version          10.1 / 10.1
  CUDA Capability Major/Minor version number:    5.0
  Total amount of global memory:                 2048 MBytes (2147483648 bytes)
  ( 3) Multiprocessors, (128) CUDA Cores/MP:     384 CUDA Cores
  GPU Max Clock rate:                            1242 MHz (1.24 GHz)
  Memory Clock rate:                             1001 Mhz
  Memory Bus Width:                              64-bit
  L2 Cache Size:                                 1048576 bytes
  Maximum Texture Dimension Size (x,y,z)         1D=(65536), 2D=(65536, 65536), 3D=(4096, 4096, 4096)
  Maximum Layered 1D Texture Size, (num) layers  1D=(16384), 2048 layers
  Maximum Layered 2D Texture Size, (num) layers  2D=(16384, 16384), 2048 layers
  Total amount of constant memory:               zu bytes
  Total amount of shared memory per block:       zu bytes
  Total number of registers available per block: 65536
  Warp size:                                     32
  Maximum number of threads per multiprocessor:  2048
  Maximum number of threads per block:           1024
  Max dimension size of a thread block (x,y,z): (1024, 1024, 64)
  Max dimension size of a grid size    (x,y,z): (2147483647, 65535, 65535)
  Maximum memory pitch:                          zu bytes
  Texture alignment:                             zu bytes
  Concurrent copy and kernel execution:          Yes with 4 copy engine(s)
  Run time limit on kernels:                     Yes
  Integrated GPU sharing Host Memory:            No
  Support host page-locked memory mapping:       Yes
  Alignment requirement for Surfaces:            Yes
  Device has ECC support:                        Disabled
  CUDA Device Driver Mode (TCC or WDDM):         WDDM (Windows Display Driver Model)
  Device supports Unified Addressing (UVA):      Yes
  Device supports Compute Preemption:            No
  Supports Cooperative Kernel Launch:            No
  Supports MultiDevice Co-op Kernel Launch:      No
  Device PCI Domain ID / Bus ID / location ID:   0 / 2 / 0
2

Take a look at the source code. Presumably it prints the number of bytes with the %zu format of printf(), which is the correct format for size_t variables.

I am guessing that either the ‘%’ character went missing in the source code, or that your host tool chain does not support the %zu format specifier. That format specifier was introduced twenty years ago in ISO C99 (and more recently incorporated into ISO C++11), but I seem to vaguely recall that Microsoft didn’t support it until MSVS 2013.

3

Thank you very much! But I can’t see the source code of the exe. I turn to CUDA-Z and the problem is gone.

4

The source of the deviceQuery app used to be part of the sample programs that ship with CUDA. I wasn’t aware that has changed.

5

Oh I just forgot it, thanks:)