If you can't modify the kernel to collect more accurate data (like we did with our top-oid in OSE), you have to get a lot smarter. Set up some 'offline' processing of bulk data, NON-clock synchronized, and characterize that. (i.e. I can process 1000 records/second in a non-clock-synced loop, therefore each record takes 1msec. Normal clock-synced behavior is 1 record per clock invocation.)
Etc. It's a pain. -- Jim -----Original Message----- From: busybox [mailto:[email protected]] On Behalf Of Grant Edwards Sent: Friday, November 14, 2014 2:26 PM To: [email protected] Subject: Re: Accuracy/reliability of "top" CPU usage numbers On 2014-11-14, Grant Edwards <[email protected]> wrote: > Almost all of the "real" work done on this target is clock > synchronized, so how does one determine how much CPU is being used > and by whom? The short answer is that the values shown by top are almost completely useless in this scenario. There isn't anything top can do about it, since the limitation is in the data gathered by the kernel itself. What may be surprising (until you think about it for a few seconds), is that running a single clock-driven app can completely throw off the values shown for "normal" programs. A low-priority idle program can be used to determine how much idle CPU time is available, but determining who is using how much seems to be limited to watching the idle program output change as you start/stop programs about which you want info. -- Grant Edwards grant.b.edwards Yow! Here I am in 53 at B.C. and all I want is a gmail.com dill pickle!! _______________________________________________ busybox mailing list [email protected] http://lists.busybox.net/mailman/listinfo/busybox _______________________________________________ busybox mailing list [email protected] http://lists.busybox.net/mailman/listinfo/busybox
