Segmentation fault for repeated execution of a reduction kernel on a 4850

Discussion created by jopakastner on Sep 12, 2008
Latest reply on Sep 17, 2008 by MicahVillmow


the following brook+ code results in a segmentation fault on my 4850 with SDK 1.2 and Catalyst 8.8:

reduce void sum(float a<>, reduce float b<> {
    b = b + a;



int main() {
    float x<10>;
    float x_in[10];
    float s;
    int i;

    for (i=0; i<9; i++)
        x_in = (float)i;


    sum(x,s);  // 2 calls to sum are OK
    sum(x,s);  // 3rd call --> segmentation fault

    return 0;

This error is somewhat weird, since two succesive calls to the reduction kernel work fine, but the third call results in a segmentation fault. The same problem occurs if the reduction kernel is part of a for- or while-loop. Has anyone experienced a similar problem?

My configuration:
- OpenSuSE 11.0 64bit
- HD 4850
- Stream SDK 1.2
- Catalyst 8.8


--- johannes