My program runs in background. I use linux top command, it shows 16g memory. But when I want to use go pprof -inuse_space to check the point, I gives only 200M. Where do the other memory go?
Generally, the memory used in os(shown by top VIRT) is larger than pprof. One reason is gc will happen when heap size > ($GOGC% + 1) * (reachable nodes size): https://blog.golang.org/go15gc. By default, $GOGC is 100, that means the memory size will be twice of the heap size shown by pprof. But you seem not to be in this case.