проблема с php-cgi+ngninx

переодически вижу вот такое в логе.

 kernel: pid 8784 (php-cgi), uid 80: exited on signal 6
 kernel: pid 8771 (php-cgi), uid 80: exited on signal 6

php-5.2.6 у меня стоит

в логах php-fpm

вот это

Nov 17 11:06:10.318183 [WARNING] fpm_stdio_child_said(), line 158: child 
24729 (pool main) said into stderr: "php-cgi"
Nov 17 11:06:10.318252 [WARNING] fpm_stdio_child_said(), line 158: child 
24729 (pool main) said into stderr: " in malloc():"
Nov 17 11:06:10.318273 [WARNING] fpm_stdio_child_said(), line 158: child 
24729 (pool main) said into stderr: " error: "
Nov 17 11:06:10.318294 [WARNING] fpm_stdio_child_said(), line 158: child 
24729 (pool main) said into stderr: "recursive call"
Nov 17 11:06:10.318435 [WARNING] fpm_stdio_child_said(), line 158: child 
24729 (pool main) said into stderr: "[24729] EACCEL"
Nov 17 11:06:10.318446 [WARNING] fpm_stdio_child_said(), line 158: child 
24729 (pool main) said into stderr: ""
Nov 17 11:06:10.322070 [NOTICE] fpm_got_signal(), line 48: received SIGCHLD
Nov 17 11:06:10.322215 [WARNING] fpm_children_bury(), line 215: child 
24729 (pool main) exited on signal 6 SIGABRT after 806t
Nov 17 11:06:10.322929 [NOTICE] fpm_children_make(), line 352: child 
24922 (pool main) started
Nov 17 11:08:28.772408 [WARNING] fpm_stdio_child_said(), line 158: child 
24660 (pool main) said into stderr: "php-cgi"
Nov 17 11:08:28.772451 [WARNING] fpm_stdio_child_said(), line 158: child 
24660 (pool main) said into stderr: " in malloc():"
Nov 17 11:08:28.772470 [WARNING] fpm_stdio_child_said(), line 158: child 
24660 (pool main) said into stderr: " error: "
Nov 17 11:08:28.772488 [WARNING] fpm_stdio_child_said(), line 158: child 
24660 (pool main) said into stderr: "recursive call"
Nov 17 11:08:28.772615 [WARNING] fpm_stdio_child_said(), line 158: child 
24660 (pool main) said into stderr: "[24660] EACCEL"
Nov 17 11:08:28.772625 [WARNING] fpm_stdio_child_said(), line 158: child 
24660 (pool main) said into stderr: ""
Nov 17 11:08:28.776924 [NOTICE] fpm_got_signal(), line 48: received SIGCHLD
Nov 17 11:08:28.777002 [WARNING] fpm_children_bury(), line 215: child 
24660 (pool main) exited on signal 6 SIGABRT after 944t
Nov 17 11:08:28.778190 [NOTICE] fpm_children_make(), line 352: child 
24939 (pool main) started

в какую сторону копать ?