On Mon, 2008-12-08 at 07:25 -0800, Barton Robinson wrote: > Sorry Christian, but with the latest and greatest, there are many cases where > Linux and > TOP now seriously under report utilization (I think by factor of 5 in the > lab, and by 4 in > a production server). Not sure we've bothered to report the details since > this problem > would not impact our users. So the data still can not be used for serious > performance > work, capacity planning or accounting/chargeback. It's like putting gas in a > car, and the > price per "unit" varies with the number of other people wanting gas. Doesn't > lead one to > trust the instrumentation.
1) Rob, please report these discrepancies. The numbers linux reports should be correct. 2) The factor of 4-5 is based on what numbers exactly? I doubt that you get that discrepancy if you are running a cpu bound linux process that uses more than a few percent of cpu. As already pointer out the situation that started this thread is very likely a multi threaded program and top aggregates the cputime. 3) Top is by no means a monitoring tool. You can use it to get a rough snapshot of the current situation but please don't use it instead of a real monitor because top itself uses a lot of cpu. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
