Nginx or PHP FPM ignores memory_limit in php.ini
The problem may be in fpm the process duplication, even you change your /etc/php5/fpm/php.ini it was not effect.
- Stop php5-fpm with (ubuntu): sudo service php5-fpm stop
- check that no more fpm processes: sudo ps ax | grep fpm
- if any kill it all with: sudo kill -9 pid
- be sure that you kill all fpm processes
- restart: sudo service php5-fpm restart
You can take Nginx out of the picture, it just passes the request on, it's in php-fpm running your php code.
you might check your suhosin settings, suhosin.memory_limit.
when you see your phpinfo output there should be 2 columns, master and local for memory_limit, what do these each show?
128M is the default for memory_limit in php 5.3
In /etc/php5/fpm/php-fpm.conf
I have php_admin_value[memory_limit] = 512M
This works for me.