Possible Duplicate:
C programming, why does this large array declaration produce a segmentation fault?
Why does this program crash? It works fine for a max of 1e6, and works fine if I don't set every value to 0.
Doesn't the program get all of the memory allocated?
int main() {
const int max = 10000000; // 1e7
int end[max];
unsigned int i;
for ( i = 0; i < max; i++ )
end[i] = 0;
}
$ gcc test.c && ./a.out
Segmentation fault (core dumped)
Variable-length arrays are usually allocated on the stack. Stack space is limited; you are probably getting a stack overflow here. You can't allocate a very large size like that on such memory location. Your array is too big to fit in your program's stack. A better idea to allocate such size is to allocate on the heap.
#include <stdlib.h>
int *end = malloc(sizeof *end * max);
/* some stuff */
free(end);
The heap is many times larger than the stack.
Your stack size is limited by your operating system.
If you have to allocate very big values, don't use the stack but use the heap with malloc().
It probably is a stack size problem.
You could manually check and change your stack size with setrlimit and getrlimit
http://linux.die.net/man/2/setrlimit
You can also do it when compiling with the --stack option:
gcc --stack,<your size> ...
