diff --git a/admin/cli/install_database.php b/admin/cli/install_database.php
index 87202f29ca3..17f6d59309d 100644
--- a/admin/cli/install_database.php
+++ b/admin/cli/install_database.php
@@ -85,7 +85,7 @@ if ($DB->get_tables() ) {
 $CFG->early_install_lang = true;
 get_string_manager(true);
 
-@raise_memory_limit('128M');
+raise_memory_limit(MEMORY_EXTRA);
 
 // now get cli options
 list($options, $unrecognized) = cli_get_params(
diff --git a/admin/health.php b/admin/health.php
index 385792604d0..e18a052c059 100644
--- a/admin/health.php
+++ b/admin/health.php
@@ -330,7 +330,7 @@ class problem_000008 extends problem_base {
         global $CFG;
 
         $oldmemlimit = @ini_get('memory_limit');
-        if(empty($oldmemlimit)) {
+        if (empty($oldmemlimit)) {
             // PHP not compiled with memory limits, this means that it's
             // probably limited to 8M or in case of Windows not at all.
             // We can ignore it for now - there is not much to test anyway
@@ -338,12 +338,9 @@ class problem_000008 extends problem_base {
             return false;
         }
         $oldmemlimit = get_real_size($oldmemlimit);
-        //now lets change the memory limit to something unique below 128M==134217728
-        if (empty($CFG->extramemorylimit)) {
-            raise_memory_limit('128M');
-        } else {
-            raise_memory_limit($CFG->extramemorylimit);
-        }
+        //now lets change the memory limit to something higher
+        $newmemlimit = ($oldmemlimit + 1024*1024*5);
+        raise_memory_limit($newmemlimit);
         $testmemlimit = get_real_size(@ini_get('memory_limit'));
         //verify the change had any effect at all
         if ($oldmemlimit == $testmemlimit) {
diff --git a/admin/report/security/index.php b/admin/report/security/index.php
index d4415eb0e63..ddb96d73097 100644
--- a/admin/report/security/index.php
+++ b/admin/report/security/index.php
@@ -39,7 +39,7 @@ if (array_search($issue, $issues, true) === false) {
 }
 
 // we may need a bit more memory and this may take a long time to process
-@raise_memory_limit('128M');
+raise_memory_limit(MEMORY_EXTRA);
 @set_time_limit(0);
 
 // Print the header.
diff --git a/admin/report/unittest/index.php b/admin/report/unittest/index.php
index 0f56a167467..6ccc938caf6 100644
--- a/admin/report/unittest/index.php
+++ b/admin/report/unittest/index.php
@@ -18,7 +18,7 @@ require_once('ex_reporter.php');
 // Always run the unit tests in developer debug mode.
 $CFG->debug = DEBUG_DEVELOPER;
 error_reporting($CFG->debug);
-raise_memory_limit('256M');
+raise_memory_limit(MEMORY_EXTRA);
 
 // page parameters
 $path         = optional_param('path', null, PARAM_PATH);
diff --git a/backup/lib.php b/backup/lib.php
index 2ced1d52180..885c7caeb51 100644
--- a/backup/lib.php
+++ b/backup/lib.php
@@ -556,11 +556,7 @@
             return false;
         }
         @ini_set("max_execution_time","3000");
-        if (empty($CFG->extramemorylimit)) {
-            raise_memory_limit('128M');
-        } else {
-            raise_memory_limit($CFG->extramemorylimit);
-        }
+        raise_memory_limit(MEMORY_EXTRA);
 
         if (!$backup_unique_code = restore_precheck($destinationcourse,$pathtofile,$errorstr,true)) {
             mtrace($debuginfo.'Failed restore_precheck (error was '.$errorstr.')');
diff --git a/enrol/database/lib.php b/enrol/database/lib.php
index 185d5fc3aa0..b99090ce319 100644
--- a/enrol/database/lib.php
+++ b/enrol/database/lib.php
@@ -244,7 +244,7 @@ class enrol_database_plugin extends enrol_plugin {
 
         // we may need a lot of memory here
         @set_time_limit(0);
-        @raise_memory_limit("512M");
+        raise_memory_limit(MEMORY_HUGE);
 
         $extdb = $this->db_init();
 
@@ -477,7 +477,7 @@ class enrol_database_plugin extends enrol_plugin {
 
         // we may need a lot of memory here
         @set_time_limit(0);
-        @raise_memory_limit("512M");
+        raise_memory_limit(MEMORY_HUGE);
 
         $extdb = $this->db_init();
 
diff --git a/enrol/ldap/lib.php b/enrol/ldap/lib.php
index 86be4665aa5..04472b086b8 100644
--- a/enrol/ldap/lib.php
+++ b/enrol/ldap/lib.php
@@ -138,7 +138,7 @@ class enrol_ldap_plugin extends enrol_plugin {
 
         // We may need a lot of memory here
         @set_time_limit(0);
-        @raise_memory_limit("512M");
+        raise_memory_limit(MEMORY_HUGE);
 
         // Get enrolments for each type of role.
         $roles = get_all_roles();
@@ -297,7 +297,7 @@ class enrol_ldap_plugin extends enrol_plugin {
 
         // we may need a lot of memory here
         @set_time_limit(0);
-        @raise_memory_limit("512M");
+        raise_memory_limit(MEMORY_HUGE);
 
         // Get enrolments for each type of role.
         $roles = get_all_roles();
diff --git a/grade/import/csv/index.php b/grade/import/csv/index.php
index 69d147d7b5f..4cd70b3dd45 100755
--- a/grade/import/csv/index.php
+++ b/grade/import/csv/index.php
@@ -100,7 +100,7 @@ if ($formdata = $mform->get_data()) {
     // that we'll take longer, and that the process should be recycled soon
     // to free up memory.
     @set_time_limit(0);
-    @raise_memory_limit("192M");
+    raise_memory_limit(MEMORY_EXTRA);
 
     // use current (non-conflicting) time stamp
     $importcode = get_new_importcode();
@@ -205,7 +205,7 @@ if ($formdata = $mform->get_data()) {
     // that we'll take longer, and that the process should be recycled soon
     // to free up memory.
     @set_time_limit(0);
-    @raise_memory_limit("192M");
+    raise_memory_limit(MEMORY_EXTRA);
 
     // we only operate if file is readable
     if ($fp = fopen($filename, "r")) {
diff --git a/grade/import/xml/import.php b/grade/import/xml/import.php
index baf7510c450..3c941f090f1 100644
--- a/grade/import/xml/import.php
+++ b/grade/import/xml/import.php
@@ -44,7 +44,7 @@ require_capability('gradeimport/xml:view', $context);
 // that we'll take longer, and that the process should be recycled soon
 // to free up memory.
 @set_time_limit(0);
-@raise_memory_limit("256M");
+raise_memory_limit(MEMORY_EXTRA);
 
 $text = download_file_content($url);
 if ($text === false) {
diff --git a/grade/import/xml/index.php b/grade/import/xml/index.php
index efa2f2ab332..5ce766b4331 100755
--- a/grade/import/xml/index.php
+++ b/grade/import/xml/index.php
@@ -48,7 +48,7 @@ if ($data = $mform->get_data()) {
     // that we'll take longer, and that the process should be recycled soon
     // to free up memory.
     @set_time_limit(0);
-    @raise_memory_limit("256M");
+    raise_memory_limit(MEMORY_EXTRA);
 
     if ($text = $mform->get_file_content('userfile')) {
         print_grade_page_head($COURSE->id, 'import', 'xml', get_string('importxml', 'grades'));
diff --git a/lib/cronlib.php b/lib/cronlib.php
index 76b6e61b798..d1904879550 100644
--- a/lib/cronlib.php
+++ b/lib/cronlib.php
@@ -52,7 +52,7 @@ function cron_run() {
     $starttime = microtime();
 
 /// increase memory limit (PHP 5.2 does different calculation, we need more memory now)
-    @raise_memory_limit('128M');
+    raise_memory_limit(MEMORY_EXTRA);
 
 /// emulate normal session
     cron_setup_user();
@@ -333,7 +333,7 @@ function cron_run() {
         //Execute backup's cron
         //Perhaps a long time and memory could help in large sites
         @set_time_limit(0);
-        @raise_memory_limit("192M");
+        raise_memory_limit(MEMORY_EXTRA);
         if (file_exists("$CFG->dirroot/backup/backup_scheduled.php") and
             file_exists("$CFG->dirroot/backup/backuplib.php") and
             file_exists("$CFG->dirroot/backup/lib.php") and
diff --git a/mod/assignment/type/online/assignment.class.php b/mod/assignment/type/online/assignment.class.php
index fce9463f28f..7317f3e0c8b 100644
--- a/mod/assignment/type/online/assignment.class.php
+++ b/mod/assignment/type/online/assignment.class.php
@@ -385,7 +385,7 @@ class assignment_online extends assignment_base {
     public function download_submissions() {
         global $CFG, $DB;
 
-        @raise_memory_limit('256M');
+        raise_memory_limit(MEMORY_EXTRA);
 
         $submissions = $this->get_submissions('','');
         if (empty($submissions)) {
@@ -403,7 +403,7 @@ class assignment_online extends assignment_base {
         } else {
             $groupmode = $this->course->groupmode;
         }
-        
+
         $groupid = 0;   // All users
         $groupname = '';
         if ($groupmode) {
diff --git a/mod/data/import.php b/mod/data/import.php
index 8352780c76b..346c54ff692 100755
--- a/mod/data/import.php
+++ b/mod/data/import.php
@@ -107,7 +107,7 @@ if (!$formdata = $form->get_data()) {
     // that we'll take longer, and that the process should be recycled soon
     // to free up memory.
     @set_time_limit(0);
-    @raise_memory_limit("96M");
+    raise_memory_limit(MEMORY_EXTRA);
 
     $iid = csv_import_reader::get_new_iid('moddata');
     $cir = new csv_import_reader($iid, 'moddata');
diff --git a/search/cron_php5.php b/search/cron_php5.php
index 276147332b8..fa53cc17408 100644
--- a/search/cron_php5.php
+++ b/search/cron_php5.php
@@ -2,7 +2,7 @@
 /*
 * Moodle global search engine
 * This is a special externalized code for cron handling in PHP5.
-* Should never be called by a php 4.3.0 implementation. 
+* Should never be called by a php 4.3.0 implementation.
 * @package search
 * @category core
 * @subpackage search_engine
@@ -14,11 +14,7 @@
 
 try{
     ini_set('max_execution_time', 300);
-    if (empty($CFG->extramemorylimit)) {
-        raise_memory_limit('128M');
-    } else {
-        raise_memory_limit($CFG->extramemorylimit);
-    }
+    raise_memory_limit(MEMORY_EXTRA);
 
     mtrace("\n--DELETE----");
     require_once($CFG->dirroot.'/search/delete.php');
diff --git a/webservice/lib.php b/webservice/lib.php
index 1b4f9f002e5..bc9c4ce6999 100644
--- a/webservice/lib.php
+++ b/webservice/lib.php
@@ -701,7 +701,7 @@ abstract class webservice_zend_server extends webservice_server {
      */
     public function run() {
         // we will probably need a lot of memory in some functions
-        @raise_memory_limit('128M');
+        raise_memory_limit(MEMORY_EXTRA);
 
         // set some longer timeout, this script is not sending any output,
         // this means we need to manually extend the timeout operations
@@ -1141,7 +1141,7 @@ abstract class webservice_base_server extends webservice_server {
      */
     public function run() {
         // we will probably need a lot of memory in some functions
-        @raise_memory_limit('128M');
+        raise_memory_limit(MEMORY_EXTRA);
 
         // set some longer timeout, this script is not sending any output,
         // this means we need to manually extend the timeout operations