We have no doubt that it is based on reality because public companies do not make things up in order to avoid lawsuits. The company has never defined its performance criteria publicly. During the launch event, however, Apple compared the new M2 chipset to the Core i7 processor.
M2 AND DIM3 HOW TO
You can use a similar method to track those down (perhaps using printf to spit out the computed indexes, or else testing the indexes for validity).Īlthough the above description uses cuda-memcheck, the compute-sanitizer tool works similarly, and is the recommended one at the time of this edit.įor another example of how to use this method to narrow down the source of a problem, see here.To date, there is no report that compares both the chipset and statistics on which one is faster. You've got lots of complicated indexing going on in your kernel, so I'm pretty sure there are other errors as well. Trying to read from M1 will create a fault. for thread (0,0) in your 2D thread array)? It evaluates to -2048 (i.e. What does this evaluate to when i=0 and j=0 (ie. But we already have a clue that we are indexing out-of-bounds, so let's inspect the indexing: i + ROOM_X *(j-1) We could debug further, perhaps using in-kernel printf statements to discover where the problem is. This line happens to be this line of kernel code: float M1_IndexRight = M1 With the lineinfo information, we can see that this occurred: = at 0x00000070 in /home/bob/misc/t615.cu:34:SolverGPU(float*, float*) an out of bounds access trying to read an int or float quantity, for example). This means that the very first error encountered by your kernel was an invalid global read of size 4 (i.e. = Host Frame:/lib64/libc.so.6 (_libc_start_main + 0xf4) = Host Frame:/usr/lib64/libcuda.so.1 (cuLaunchKernel + 0x2cd)
M2 AND DIM3 DRIVER
= Saved host backtrace up to driver entry point at kernel launch time Now we get output that looks like this: $ nvcc -arch=sm_20 -lineinfo -o t615 t615.cu
M2 AND DIM3 CODE
We can get additional clarity if we recompile your code adding the -lineinfo switch (or alternatively with -G), and then re-run your code with cuda-memcheck. This means that you are making an out-of-bounds memory access. cc7.0 or newer, you should use compute-sanitizer instead of cuda-memcheck, but otherwise the process here is identical.) If we run your program with cuda-memcheck, we get some additional output that indicates that the kernel is doing invalid global reads of size 4. But we don't need to pull out the debugger just yet.Ī useful tool is cuda-memcheck. You can debug kernel execution problems using a debugger, such as cuda-gdb on linux, or Nsight VSE on windows. But we can proceed forward regardless.Įither message indicates that the kernel launched but encountered an error, and so failed to complete successfully. The exact error reporting will depend on CUDA version, GPU, and platform. You may indeed be getting "unspecified launch failure" instead. When I compile and run your code, I get: an illegal memory access was encountered-3 I guess that's the error is quite simple, but can't figure to find it. But I can't find the error (s) in the kernel. Ok, so I've read that it's usually due to the kernel which doesn't run properly. Whne I check my errors, the "unspecified launch failure" appears on the memcpy AFTER the kernel. Printf("%s-%d",cudaGetErrorString(err),3) Here is the kernel and a function that fill a matrix : #include "solver.h"Įrr=cudaMemcpy(M1_h, M1_d, size, cudaMemcpyDeviceToHost) _global_ void SolverGPU(float* M1, float* M2) Here is the header, its name is "sole : #define ITER_BETWEEN_SAVES 10000 ROOM_X ans ROOM_Y are the width and height of the matrices.
The program is a solver of a differential equation. I'm encountering an "unspecified launch failure" when running my program in Cuda.
0 kommentar(er)
