# app/config/config.yml
# AdminLog Configuration
services:
    admin_log:
        class:        xyzBundleCoreBundleServiceAdminLogService
        arguments:    [@doctrine.orm.entity_manager]

<?php
namespace xyzBundleCoreBundleService;
use xyzBundleCoreBundleEntityAdminLog;

class AdminLogService
{
    protected $em;

    public function __construct(DoctrineORMEntityManager $em)
    {
        $this->em = $em;
    }

    public function logActivity($controller, $action, $entityName, $note)
    {
        $adminLog = new AdminLog(
            1,
            $controller,
            $action,
            $entityName,
            $note
        );
        $this->em->persist($adminLog);
        $this->em->flush();
    }

}

$this->get('admin_log')->logActivity('Website', 'index', 'Test', 'Note here...');