Date: Thu, 2 May 2002 16:15:05 -0700 (PDT) From: Patrick Thomas <root@utility.clubscholarship.com> To: <freebsd-questions@freebsd.org> Subject: confusing CPU stats in `top` Message-ID: <20020502160811.P29785-100000@utility.clubscholarship.com>
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background: normally, when I run `top` in a multu processor system, the CPU percentage summary tells me the percentage being used of the entire 4 processor range. So, if for instance the system is lightly loaded (99.9% idle) and suddenly some process takes up a ton of cycles, I will see this in `top`: 92731 88 2 0 42280K 18464K poll 1 238:30 99.95% 99.95% mysqld BUT - in the summary at the top of `top`, I will see roughly 74.9% idle - since only one of the four CPUs is being eaten up. THis makes sense, and it what I have learned to look for in 4-proc systems. ---- So what is happening here ? last pid: 24283; load averages: 1.71, 2.07, 2.62 up 97+17:51:18 16:09:59 964 processes: 4 running, 956 sleeping, 4 zombie CPU states: 11.1% user, 0.2% nice, 19.0% system, 0.0% interrupt, 69.7% idle Mem: 1289M Active, 234M Inact, 376M Wired, 82M Cache, 199M Buf, 28M Free Swap: 2018M Total, 6316K Used, 2012M Free PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU CPU COMMAND 92645 88 2 0 42280K 18464K poll 1 238:30 38.82% 38.82% mysqld 56036 root 2 0 1836K 1316K select 1 21:58 6.84% 6.84% master 8398 88 2 0 39272K 20700K poll 0 996:14 5.47% 5.47% mysqld 23617 root 31 0 2968K 2108K CPU1 2 0:01 5.31% 2.54% top 19435 1006 2 20 48916K 39828K poll 0 35:20 1.12% 1.12% httpd 93802 500 2 0 64804K 61024K sbwait 1 2:40 0.63% 0.63% httpd 87873 root 2 0 1596K 1180K select 2 0:01 0.20% 0.20% proftpd 93750 500 2 0 70352K 66716K accept 1 3:24 0.15% 0.15% httpd 93751 500 2 0 66396K 62412K accept 0 3:02 0.15% 0.15% httpd 4965 500 2 0 49084K 45436K sbwait 2 0:02 0.10% 0.10% httpd 53925 user 38 5 10652K 4960K CPU2 0 7:40 0.05% 0.05% ack 747 root 2 0 872K 284K poll 2 159:24 0.00% 0.00% httpd 68955 root 2 0 872K 368K poll 1 148:05 0.00% 0.00% httpd 96533 72 2 0 13360K 12624K poll 0 29:00 0.00% 0.00% ircd As you can see, the server reports 69.7% idle BUT, that would imply processes using up a total of (30.3 x 4) `top` reported percent ... which is not the case - if you add up the percentages in the `top` reported processes, they add up to ~58 or so, and if we divide that by four we would expect to see 85% idle or so, instead of 69.7% idle. So why is this exhibiting this behavior, when as I said, if you have a non-loaded system, and a single process goes to 99%, the overall load is roughly 74% ?? thanks, PT To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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