Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!floyd!harpo!seismo!hao!hplabs!sri-unix!ALMQUIST@SU-SCORE.ARPA From: ALMQUIST@SU-SCORE.ARPA Newsgroups: net.unix Subject: Re: 4.1bsd accounting question Message-ID: <17296@sri-arpa.UUCP> Date: Wed, 7-Mar-84 19:29:00 EST Article-I.D.: sri-arpa.17296 Posted: Wed Mar 7 19:29:00 1984 Date-Received: Sat, 10-Mar-84 08:15:37 EST Lines: 14 From: Philip AlmquistI've never tried to do such analysis on a UNIX system, but such problems (user time + system time /= real time) seems to be quite common. Under Tops-20, for example, the sum of user time and system time seems to vary between about 70% and 115% of real time. The reasons seem to be both due to numerical (rounding) problems and to data collection problems (some time is counted as both kinds or not at all). Solving the latter problem is actually a rather subtle task, since you need an atomic way of switching which clock you are charging the time to and since there are a great many places where the average OS can switch between "user tasks" and "system tasks". Philip -------