in your example, there are 8 groups of lsphp5, lsphp5 in one group share 1 APC cache. for example, lsphp5 pid=31153,776,1944,31744 are in one group. the parent process is 31153, the rest are child processes and share APC cache created by 31153.
but share cache between groups of lsphp5 is not...