After enable ACL module , all php-fpm process load CPU 100%

Hi! Help me plz!
HW param: CPU 8 core , 6Gb RAM
I'm use Drupal 7.34 , system CentOS release 6.7, php 5.4
nginx + php-fpm
Problem! if i enable module ACL, all php-fpm process load CPU over 100%
after disable module ACL, CPU load is normal, Why ?