I really dislike the fact that during intense IO operations (like copying a file from one partition to another one) you cannot see the actual CPU usage because kernel (via proc fs) reports that one of the CPUs is 100% busy. Most people, when faced with such statistics, will judge with all confidence, that CPU is indeed 100% busy which is not true. One could think that this is probably a userspace bug, but I tend not to think this way, because both top and htop utitities report the same data. Furthermore, this simple test: cat big_file > /dev/null will raise load average to 1.00 which means that at least one of the CPUs in a system is 100% busy and load average is a _direct_ kernel counter, so, top and htop cannot be wrong. That doesn't make sense. Please, fix this bug. If a CPU is indeed busy waiting for IO operations to complete, then a real IO wait time should be reported. P.S. Kernel 2.4.x did not have this problem.
Gnome System Monitor doesn't have this problem, closing.