Description:
------------
Additional modules added to PHP:

/etc/php5/apache2/conf.d/apc.ini, 
/etc/php5/apache2/conf.d/curl.ini, 
/etc/php5/apache2/conf.d/cwioncube.ini, 
/etc/php5/apache2/conf.d/cwzend-optimizer.ini, 
/etc/php5/apache2/conf.d/gd.ini, 
/etc/php5/apache2/conf.d/gmp.ini, 
/etc/php5/apache2/conf.d/imap.ini, 
/etc/php5/apache2/conf.d/interbase.ini, 
/etc/php5/apache2/conf.d/ldap.ini, 
/etc/php5/apache2/conf.d/mapscript.ini, 
/etc/php5/apache2/conf.d/mcrypt.ini, 
/etc/php5/apache2/conf.d/memcache.ini, 
/etc/php5/apache2/conf.d/mhash.ini, 
/etc/php5/apache2/conf.d/mssql.ini, 
/etc/php5/apache2/conf.d/mysql.ini, 
/etc/php5/apache2/conf.d/mysqli.ini, 
/etc/php5/apache2/conf.d/odbc.ini, 
/etc/php5/apache2/conf.d/pdo.ini, 
/etc/php5/apache2/conf.d/pdo_dblib.ini, 
/etc/php5/apache2/conf.d/pdo_firebird.ini, 
/etc/php5/apache2/conf.d/pdo_mysql.ini, 
/etc/php5/apache2/conf.d/pdo_odbc.ini, 
/etc/php5/apache2/conf.d/pdo_pgsql.ini, 
/etc/php5/apache2/conf.d/pdo_sqlite.ini, 
/etc/php5/apache2/conf.d/pgsql.ini, 
/etc/php5/apache2/conf.d/php_exec.ini, 
/etc/php5/apache2/conf.d/pspell.ini, 
/etc/php5/apache2/conf.d/recode.ini, 
/etc/php5/apache2/conf.d/snmp.ini, 
/etc/php5/apache2/conf.d/sqlite.ini, 
/etc/php5/apache2/conf.d/tidy.ini, 
/etc/php5/apache2/conf.d/xmlrpc.ini, 
/etc/php5/apache2/conf.d/xsl.ini


When setting apc.cache_by_default to On I get 500 errors and 
after trying to reload the page over and over again I get:

Fatal error: Allowed memory size of 1073741824 bytes 
exhausted (tried to allocate 3266497821 bytes) in Unknown on 
line 0

Notice that during my debugging of this behavior I set the 
memory_limit of PHP to 1024M. A number no script should hit.

As a test I put the code: echo "something"; into a PHP file 
and tried to load it. Out of 30 tries 23 were WSOD, 4 gave 
me a line similar to ((Fatal error: Allowed memory size of 
1073741824 bytes exhausted (tried to allocate 2039749994 
bytes) in Unknown on line 0)) and 3 times the file loaded 
and printing, "something" as output.

A file that is simply echoing a string should not require a 
gig of memory!

Also note: If I turn off opcode caching via:
apc.cache_by_default=Off

I can then use the APC cache to put and get information. So 
this only seems to effect the system cache entries. User 
cache entries work just fine.

Reproduce code:
---------------
Any PHP coding will trigger the problem. However, simply putting <? ?> with nothing to parse will not.

Expected result:
----------------
something

Actual result:
--------------
Fatal error: Allowed memory size of 1073741824 bytes exhausted 
(tried to allocate 2039749994 bytes) in Unknown on line 0