Red Hat Bugzilla – Bug 76797
top idle time incorrect
Last modified: 2007-04-18 12:47:58 EDT
From Bugzilla Helper: User-Agent: Mozilla/4.0 (compatible; MSIE 5.5; Windows 98; T312461) Description of problem: Idle time incorrect in top (procps-2.0.7-11) Version-Release number of selected component (if applicable): How reproducible: Sometimes Steps to Reproduce: 1.top 2.wait for less than 10 seconds on machine with load average over 1 3.watch idle time alternate between 0% and 8xxxxx.x% Actual Results: 128 processes: 122 sleeping, 6 running, 0 zombie, 0 stopped CPU states: 0.7% user, 2.1% system, 97.2% nice, 843804.7% idle Mem: 255744K av, 250980K used, 4764K free, 0K shrd, 55260K buff Swap: 554184K av, 26080K used, 528104K free 108344K cached PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND Expected Results: 0% idle Additional info: Linux 2.4.18-17.7.xcustom (root@malacandra) procinfo -f seems to display correct information
I am running Red Hat 7.3. This is my experience with this bug: I've recently upgraded to kernel-2.4.18-17.7.x.athlon.rpm (from kernel-2.4.18-10.athlon.rpm) and I've noticed a problem with the CPU idle %. Here is an example of what happens when running "top": 10:37am up 8 days, 22:02, 9 users, load average: 1.00, 1.01, 1.00 89 processes: 81 sleeping, 7 running, 1 zombie, 0 stopped CPU states: 0.1% user, 0.1% system, 99.8% nice, 857278.7% idle Mem: 514156K av, 485724K used, 28432K free, 0K shrd, 57956K buff Swap: 522072K av, 44048K used, 478024K free 288448K cached PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND 18840 mersenne 39 19 14996 14M 696 R N 99.9 2.9 7046m mprime 14091 marco 15 0 1084 1084 848 R 0.1 0.2 0:00 top 1 root 15 0 472 444 420 S 0.0 0.0 0:04 init 2 root 15 0 0 0 0 SW 0.0 0.0 0:01 keventd 3 root 15 0 0 0 0 SW 0.0 0.0 0:00 kapmd As you can see the idle value is absurd (it blows up about 1 in five times, other updates are reasonable e.g. 0.2% idle). When running "top" the value consistently jumps to about 800000% about 20% of the time. If I run "top -d1" so that the updates take place every second the value consistently jumps to about 4200000%, again about 20% of the time. Running "top -d2" makes it jump to around 2000000%. The idle value behaves approximately as follows: 4200000 idle = --------% once every five updates. interval If I stop "mprime" so that the system load becomes negligible the idle value does not spike. If I run "mprime" or any other CPU-consuming task (e.g. yes > /dev/null) the spikes commence. The niceness of the process does not seem to matter. My hardware is an Athlon 2100+ running on an ASUS A7V333. > uname -a Linux reimeika.math.toronto.edu 2.4.18-17.7.x #1 Tue Oct 8 11:49:30 EDT 2002 i686 unknown > top --version top (procps version 2.0.7) > rpm -q procps procps-2.0.7-12
*** This bug has been marked as a duplicate of 71237 ***