Re: high %CPU values after upgrading to the last stable kernel

Frédéric Weisbecker
2008-10-22T21:05:23Z

2008/10/22 sbs <gexlie@gmail.com>:
> after upgrading from 2.6.16 to 2.6.27 kernel top shows a strange
> picture of extremely highly %CPU values.
>
> # top -V
> top: procps version 3.2.6
>
>
> # top
> top - 04:24:06 up 7 days, 1:12, 1 user, load average: 2.28, 2.03, 2.00
> Tasks: 183 total, 2 running, 181 sleeping, 0 stopped, 0 zombie
> Cpu(s): 36.2% us, 2.4% sy, 0.0% ni, 56.1% id, 4.7% wa, 0.1% hi, 0.5% si
> Mem: 12473092k total, 11169060k used, 1304032k free, 16k buffers
> Swap: 2048248k total, 636k used, 2047612k free, 1257988k cached
>
> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
> 19824 b 20 0 92212 17m 5420 S 4308 0.1 1:39.49 httpd
> 14396 b 20 0 92716 28m 16m S 3721 0.2 38:47.38 httpd
> 14024 b 20 0 92376 28m 16m S 2437 0.2 51:49.68 httpd
> 7415 b 20 0 96876 40m 24m D 2146 0.3 93:59.72 httpd
> 8182 b 20 0 94500 36m 21m S 1997 0.3 111:41.60 httpd
> 13461 b 20 0 94240 31m 17m S 1439 0.3 48:43.71 httpd
> 8466 b 20 0 92036 32m 21m S 1136 0.3 107:37.90 httpd
> 17620 b 20 0 92660 23m 11m S 1003 0.2 10:55.03 httpd
> 14025 b 20 0 92000 28m 16m S 720 0.2 51:49.49 httpd
> 3808 nobody 20 0 3013m 2.9g 592 S 714 24.7 343030:50 memcached
> 10 root 15 -5 0 0 0 S 714 0.0 11881:28 ksoftirqd/3
> 18487 b 20 0 91416 20m 9572 S 580 0.2 8:29.20 httpd
> 13252 b 20 0 93408 30m 17m S 580 0.3 45:19.69 httpd
> 17525 b 20 0 93208 23m 10m S 566 0.2 18:34.40 httpd
> 14760 b 20 0 93452 28m 15m S 534 0.2 57:34.65 httpd
> 3804 nobody 20 0 2995m 2.9g 592 S 441 24.6 378908:26 memcached
> 12209 b 20 0 92312 28m 16m S 279 0.2 63:28.45 httpd
>
>
>
> %CPU is 4308 here and it's not the highest value.
> i havent seen that on any previous kernel on the same server.
>
> should i upgrade procps or downgrade kernel then to get proper values back? :)
> or is it a feature of the new kernel?
>
> thank you
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Hi,

It really depends on what your box is doing at the time you capture
the cpu usage.
And it really depends too of your kernel config...