insufficient virtual memory
When I run a program on Linux, I got the following error, :
forrtl: severe (41): insufficient virtual memory
This error seems to be clear. As it says, I seem to require too many memory. But when I printed the number of memory I was requiring, it seemed to be not too much, like 1.8GB, for the system having 32GB.
Actually this bug was related to the limit of 4-Byte integer. Since the maximum number 4-Byte integer can handle is :
2^31 = 2147483648
And if the number is larger than this, 4-Byte integer cannot express correct value and shows wrong number, which is called overflow.
So I printed the value in 8-Byte integer by using cast function
int(n,kind=8), it turns out that I was requesting about 40GB!! Now I
understand the above error message is correct.
Debugging is always annoying task...