Long time running kernel = X freezes

Discussion created by Ailer on Aug 27, 2011
Latest reply on Aug 30, 2011 by Bdot


I wrote some OpenCL program, whitch do lots of calculations, so kernel run time is big (7 days on CPU). When i try to run it on GPU or APU - computer freezes after 1,5...2 seconds. So, to be sure that freeze occurs because long run time, i wrote this simple kernel:


__kernel void square(__global float* input,__global float* output,const unsigned int count)


   int i = get_global_id(0);

  int u;

for (u=0;u<count;u++)





If i set count=10000, it runs well on GPU and CPU. If i set count=1000000, it runs on CPU, but trying to run on GPU leads to X server completely freeze, and process takes 100% of CPU(fully loads one core). Trying to kill -s 9 it causes no effect - process makrs as <defunct>, and keep loads CPU (memory consumption is 0 after kill attempt). One way to stop it - reboot computer. I try to run this code on another (non-AMD) GPU - it works well.

It is possible to run it on AMD? And is it possible to run it without X(computer have no monitor, it controlled by SSH, so i just don't need X)?

SDK ver: 2.3, ati-drivers ver: 11.6, kernel ver: 2.6.39.