Re: MySQL using only 1 CPU

[Per Jessen]

Eber Duarte wrote:

> I noticed that I always have 2 processes runing on Linux doesn't
> matter the amount of concurrent connections that is running on MySQL.
> Due to that, MySQL is using only 1 CPU instead of using 8 CPUs that
> exist on this machine:

Do you have enough concurrent load to occupy 8 CPUs? 

Here's a sample 'top' from one of my machines (also 8-way):

top - 18:12:58 up 12 days, 23:22,  6 users,  load average: 2.95, 3.02, 3.53
Tasks: 177 total,   1 running, 175 sleeping,   0 stopped,   1 zombie
Cpu0  : 45.1%us, 13.2%sy,  0.0%ni, 41.4%id,  0.0%wa,  0.0%hi,  0.3%si,  0.0%st
Cpu1  : 19.0%us, 13.8%sy,  0.0%ni, 67.2%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu2  : 23.9%us, 12.7%sy,  0.0%ni, 63.4%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu3  : 32.1%us, 11.1%sy,  0.0%ni, 56.7%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu4  : 38.0%us,  9.5%sy,  0.0%ni, 52.5%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu5  : 98.4%us,  1.6%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu6  : 73.9%us, 16.3%sy,  0.0%ni,  9.8%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu7  : 36.7%us, 13.4%sy,  0.0%ni, 49.8%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:   5195036k total,  4960136k used,   234900k free,        8k buffers
Swap:  4200956k total,      244k used,  4200712k free,  3469996k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
 4575 mysql     16   0 1152m 1.0g 4792 S  249 21.0  18269:15 mysqld
16720 root      25   0     0    0    0 Z    5  0.0   0:00.15 make <defunct>



/Per Jessen, Zürich