why mysql is using 300% cpu

[jackc]

very strange

 

[jackc]

Tasks: 166 total, 1 running, 165 sleeping, 0 stopped, 0 zombie
Cpu0 : 29.7% us, 29.0% sy, 0.0% ni, 39.0% id, 0.3% wa, 0.0% hi, 2.0% si
Cpu1 : 41.9% us, 24.9% sy, 0.0% ni, 32.9% id, 0.3% wa, 0.0% hi, 0.0% si
Cpu2 : 39.3% us, 21.7% sy, 0.0% ni, 37.3% id, 1.0% wa, 0.0% hi, 0.7% si
Cpu3 : 40.4% us, 22.8% sy, 0.0% ni, 35.4% id, 1.0% wa, 0.0% hi, 0.3% si
Cpu4 : 36.5% us, 22.9% sy, 0.0% ni, 38.5% id, 1.7% wa, 0.0% hi, 0.3% si
Cpu5 : 38.7% us, 20.5% sy, 0.0% ni, 40.4% id, 0.0% wa, 0.0% hi, 0.3% si
Cpu6 : 28.5% us, 24.2% sy, 0.0% ni, 46.7% id, 0.3% wa, 0.0% hi, 0.3% si
Cpu7 : 31.9% us, 22.6% sy, 0.0% ni, 45.2% id, 0.0% wa, 0.0% hi, 0.3% si
Mem: 6093836k total, 4671832k used, 1422004k free, 729060k buffers
Swap: 1959888k total, 4596k used, 1955292k free, 2955256k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
23231 mysql 15 0 445m 288m 4948 S 397 4.9 65996:56 mysqld
25231 squid 16 0 93296 69m 1556 S 30 1.2 9405:10 squid
29226 apache 16 0 180m 41m 23m S 5 0.7 0:13.95 httpd
29296 apache 16 0 180m 35m 17m S 4 0.6 0:04.64 httpd
29204 apache 16 0 184m 42m 20m S 4 0.7 0:09.22 httpd
29275 apache 16 0 179m 38m 21m S 4 0.7 0:08.26 httpd
29291 apache 15 0 180m 36m 18m S 4 0.6 0:06.07 httpd
29227 apache 15 0 180m 40m 22m S 3 0.7 0:11.69 httpd
29215 apache 15 0 181m 41m 23m S 3 0.7 0:13.01 httpd
29235 apache 15 0 179m 40m 23m S 3 0.7 0:12.25 httpd
29278 apache 16 0 180m 38m 20m S 3 0.6 0:05.30 httpd
29290 apache 16 0 176m 34m 20m S 3 0.6 0:04.48 httpd
29212 apache 15 0 180m 40m 23m S 3 0.7 0:11.25 httpd
29209 apache 16 0 181m 43m 23m S 2 0.7 0:12.95 httpd
29213 apache 15 0 180m 41m 23m S 2 0.7 0:11.67 httpd
29216 apache 15 0 181m 42m 23m S 2 0.7 0:09.65 httpd
29234 apache 15 0 180m 41m 23m S 2 0.7 0:10.20 httpd
29222 apache 15 0 179m 40m 22m S 2 0.7 0:13.52 httpd
29211 apache 16 0 182m 42m 22m S 1 0.7 0:11.48 httpd
29232 apache 15 0 180m 39m 21m S 1 0.7 0:09.88 httpd
457 root 15 0 0 0 0 S 0 0.0 149:43.30 kjournald
29300 root 16 0 6280 1072 776 R 0 0.0 0:00.28 top

 

[nobaloney]

Where do you see that MySQL us using 300% of your CPU? I don't think that would be possible, unless you're running some kind of quantum computer.

Jeff

 

[jackc]

now it's doing over 100%, yesterday was over 300%
it's been like this for couple months already.
using mysql 5.0.27

 

[jackc]

here is a 300%

 

[nobaloney]

When I read man top I find:

%CPU  --  CPU usage
          The task's share of the elapsed CPU  time  since  the  last  screen
          update, expressed as a percentage of total CPU time.  In a true SMP
          environment, if 'Irix mode' is Off, top will  operate  in  ?Solaris
          mode'  where a task's cpu usage will be divided by the total number
          of CPUs.  You toggle 'Irix/Solaris' modes with the 'I'  interactive
          command.

and I've never seen anything over 100%. In fact I've hardly ever seen anything close. What OS Distribution are you running? What does your man top command say about the meaning of %CPU ?

Be carefull, though, if you type man top into google; you might get some unintended consquences .

Jeff

 

[jackc]

I'm using 64bit CentOS 4.4, man top saying the same.
It seems this over 100% mysqld only shows on quad-core cpu systems, all of my quad-core cpu systems seem to have this, but not the dual dual-core systems. I think somehow top combined the cpu usage of all the mysqld processes or something like that...

 

[Chrysalis]

When I read man top I find:

%CPU  --  CPU usage
          The task's share of the elapsed CPU  time  since  the  last  screen
          update, expressed as a percentage of total CPU time.  In a true SMP
          environment, if 'Irix mode' is Off, top will  operate  in  ?Solaris
          mode'  where a task's cpu usage will be divided by the total number
          of CPUs.  You toggle 'Irix/Solaris' modes with the 'I'  interactive
          command.

and I've never seen anything over 100%. In fact I've hardly ever seen anything close. What OS Distribution are you running? What does your man top command say about the meaning of %CPU ?

Be carefull, though, if you type man top into google; you might get some unintended consquences .

Jeff

weighted cpu? which can go over 100%.

 

[bdj]

Any solution to this because I have the same thing, only not reaching 300% but 130% cpu usage.