Bug 137577
| Summary: | failures of the process accounting in ps, top, and time | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 3 | Reporter: | Allen Brown <abrown> |
| Component: | kernel | Assignee: | Ernie Petrides <petrides> |
| Status: | CLOSED NOTABUG | QA Contact: | Brian Brock <bbrock> |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | 3.0 | CC: | abrown, dff, petrides, riel, tburke |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | i686 | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2004-10-30 00:38:54 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
Reassigning to PM since this is a feature request. Hello, Allen. It looks to me like the cpu usage %'s are correct, although obviously the system-wide totals have a factor of 4 figured in (on a 4-cpu system). In your 1st set of results, you have: (0.0 + 69.0 + 0.0 + 31.5) / 4 = 25.1 There is obviously some minor variation from one instant to the next (from when "top" runs to when "ps" runs). And the fact that process timing is done in 1/HZ intervals is by design (in order to have low overhead). |
From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040207 Firefox/0.8 Description of problem: Process timing measurement is incorrect. Also note that top, ps, and /proc will not charge processor time to tasks which complete their load in less than 1/HZ (a "jiffy"). Version-Release number of selected component (if applicable): kernel-smp-2.4.21-9.EL How reproducible: Always Steps to Reproduce: 1.exec'ed an app (eatcpu) 2. exec top (see output #1 below) 3. kill eatcpu 4. see output #2 below Actual Results: #1: 63 processes: 61 sleeping, 2 running, 0 zombie, 0 stopped CPU states: cpu user nice system irq softirq iowait idle total 25.1% 0.0% 0.0% 0.0% 0.0% 0.0% 74.8% cpu00 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 100.0% cpu01 69.0% 0.0% 0.0% 0.0% 0.0% 0.0% 31.0% cpu02 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 100.0% cpu03 31.5% 0.0% 0.0% 0.0% 0.0% 0.0% 68.5% Mem: 3950388k av, 602488k used, 3347900k free, 0k shrd, 162580k buff 331096k active, 25784k inactive Swap: 4096312k av, 0k used, 4096312k free 165716k cached PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME CPU COMMAND 12746 root 25 0 640 640 560 R 24.9 0.0 0:13 3 eatcpu 1 root 15 0 500 500 440 S 0.0 0.0 1:28 3 init 2 root RT 0 0 0 0 SW 0.0 0.0 0:00 0 migration/0 ---------------------------------------------------- #2 62 processes: 61 sleeping, 1 running, 0 zombie, 0 stopped CPU states: cpu user nice system irq softirq iowait idle total 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 99.9% cpu00 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 100.0% cpu01 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 100.0% cpu02 0.0% 0.0% 0.0% 0.0% 0.0% 0.2% 99.8% cpu03 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 100.0% Mem: 3950388k av, 602480k used, 3347908k free, 0k shrd, 162580k buff 331008k active, 25784k inactive Swap: 4096312k av, 0k used, 4096312k free 165716k cached PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME CPU COMMAND 1 root 15 0 500 500 440 S 0.0 0.0 1:28 1 init 2 root RT 0 0 0 0 SW 0.0 0.0 0:00 0 migration/0 3 root RT 0 0 0 0 SW 0.0 0.0 0:00 1 migration/1 Expected Results: Per CPU%'s reported in CPU states should match (or total) CPU%'s reported per PID. Additional info: