php - Why is "zero (deleted)" using so much memory? -

i'm running cloudlinux 7. keep getting lfd notifications following:

time:         thu sep  1 16:29:12 2016 -0400 account:      xxx resource:     virtual memory size exceeded:     1226 > 256 (mb) executable:   /opt/cpanel/ea-php70/root/usr/bin/lsphp.cagefs command line: lsphp pid:          102817 (parent pid:102817) killed:       no 

i created test.php code sleep(30); , used pmap track memory use. following output (truncated):

address           kbytes     rss   dirty mode  mapping 00007f68183e7000 1048576     132     132 rw-s- 0 (deleted) 00007f68583e7000      48       0       0 r-x-- libnss_files-2.17.so 00007f68583f3000    2044       0       0 ----- libnss_files-2.17.so 00007f68585f2000       4       4       4 r---- libnss_files-2.17.so 00007f68585f3000       4       4       4 rw--- libnss_files-2.17.so 00007f68585f4000      24       0       0 rw---   [ anon ] 00007f68585fa000      28      20       0 r-x-- xmlreader.so 00007f6858601000    2044       0       0 ----- xmlreader.so ---------------- ------- ------- ------- total kb         1256296    9228    6340 

it looks ram being used first line item -- zero (deleted). looking around, shared memory... why high? how lower it?