Not if you're writing UI code, networking code, most IO-related code, etc. A microsecond is very small compared to the time penalty you are likely to incur doin

Not if you're writing UI code, networking code, most IO-related code, etc. A microsecond is very small compared to the time penalty you are likely to incur doing any sort of syscall. For the vast majority of code, it's negligible. For tight, fast, repetitive code it is far too slow.