hello,

I use ab to test performance. but when i turn on accept_mutex, I found the num of connection for every nginx worker is not balance. for example,
I have 4 core and start 4 nginx worker.

ab -n 300000 -c 1000 -k "http://XXX/"

the establish connection of nginx worker

(netstat -antp|grep ESTABLISHED|awk -F" " '{print $7}'|sort|uniq -c)

644 24619/nginx:
1 24620/nginx:
53 24621/nginx:
302 24622/nginx:

but when I turn off accept_mutex

255 24660/nginx:
358 24661/nginx:
232 24662/nginx:
155 24663/nginx:

so if my test app is cpu bound, I will find one or two core of my 4 cpu are very busy but other cores are very idle

I kown accept_mutex can control accept by turn and realize worker balance by ngx_accept_disabled, but why " accpet_mutex off" seems control worker balance more well ? when accept_mutex on , one or two worker can accept connection much more than other.

thanks very much