Renato: actually Jeff’s statement is correct, since taskmgr and process explorer show the current CPU usage/load, NOT Walltime. Same thing if you use the per-process “performance graph” of Process Explorer. If you have an app that’s doing a blocking wait (and has no other active threads), it’s CPU usage graph will flatline.
When talking about absolute time usage, you’re obviously right that we’re talking Walltime and CPUTime where CPUTime is split between kernel and user. But task managers don’t show absolute usage in their graph overview, they show relative CPU usage since last update-tick.