Changes between Version 22 and Version 23 of user_applications

Timestamp:

Jan 19, 2016, 2:05:51 PM (8 years ago)

Author:

alain

Comment:

--

user_applications

@@ -54 +54 @@
 
 It can run on a multi-processors, multi-clusters architecture, with one thread per processor core. 
-The total number of threads depends on the hardware architecture, and is computed as ( x_size * y_size * nprocs ) . The main() function is executed by the thread running on P[0,0,0]. It makes several initializations, launches all other threads (using the pthread_create() function), and calls the execute() function. When the main() function returns from the execute(), it uses the
+The total number of threads depends on the hardware architecture, and is computed as ( x_size * y_size * nprocs ). The main() function is executed by the thread running on P[0,0,0]. It makes several initializations, launches all other threads (using the pthread_create() function), and calls itself the execute() function. When the main() function returns from the execute(), it uses the
 pthread_join() function to detect application completion. All others threads are executing the execute() function. Each execute() function is handling exactly (image_size / nthreads) lines.
 
 The buf_in[x,y] and buf_out[x,y] buffers containing the direct ans transposed images are distributed in clusters:
-In each cluster[x,y], the thread running on processor P[x,y,0] uses the giet_fat_mmap() function to map the buf_in[x,y] and buf_out[x,y] buffers containing a set of lines.
-Then, all threads in cluster[x,y] read pixels from the local buf_in[x,y] buffer, and write the pixels to the remote buf_out[x,y] buffers. Finally, each thread display
-a part of the transposed image to the frame buffer. There is (image size / clusters) lines per cluster. Therefore, the data read are local, but the data write are mostly remote.
+In each cluster[x,y], the thread running on processor P[x,y,0] uses the giet_fat_mmap() function to map the buf_in[x,y] and buf_out[x,y] buffers containing the set of lines that must be handled in cluster[x,y] : (image_size / nclusters) lines per cluster.
+Then, all threads in cluster[x,y] read pixels from the local buf_in[x,y] buffer, and write the pixels to the remote buf_out[x,y] buffers. Finally, each thread display a part of the transposed image to the frame buffer. Therefore, the data read are local, but the data write are mostly remote.
 
  * The image size must fit the frame buffer width and height, that must be power of 2.