爲什麼更改內核參數耗盡我的資源？

我在下面做了一個非常簡單的內核來練習CUDA。爲什麼更改內核參數耗盡我的資源？

import pycuda.driver as cuda 
import pycuda.autoinit 
import numpy as np 
from pycuda.compiler import SourceModule 
from pycuda import gpuarray 
import cv2 

def compile_kernel(kernel_code, kernel_name): 
    mod = SourceModule(kernel_code) 
    func = mod.get_function(kernel_name) 
    return func 

input_file = np.array(cv2.imread('clouds.jpg')) 
height, width, channels = np.int32(input_file.shape) 

my_kernel_code = """ 
    __global__ void my_kernel(int width, int height) { 
    // This kernel trivially does nothing! Hurray! 
    } 
""" 
kernel = compile_kernel(my_kernel_code, 'my_kernel') 

if __name__ == '__main__': 

    for i in range(0, 2): 
    print 'o' 
    kernel(width, height, block=(32, 32, 1), grid=(125, 71)) 

    # When I take this line away, the error goes bye bye. 
    # What in the world? 
    width -= 1

現在，如果我們運行上面的代碼，執行繼續執行for循環的第一次迭代就好了。但是，在循環的第二次迭代期間，我收到以下錯誤。

Traceback (most recent call last): 
    File "outOfResources.py", line 27, in <module> 
    kernel(width, height, block=(32, 32, 1), grid=(125, 71)) 
    File "/software/linux/x86_64/epd-7.3-1-pycuda/lib/python2.7/site-packages/pycuda-2012.1-py2.7-linux-x86_64.egg/pycuda/driver.py", line 374, in function_call 
    func._launch_kernel(grid, block, arg_buf, shared, None) 
pycuda._driver.LaunchError: cuLaunchKernel failed: launch out of resources

如果我拿走了這一行width -= 1，錯誤消失。這是爲什麼？我不能第二次更改內核的參數嗎？作爲參考，這裏是clouds.jpg。

enter image description here