diff --git a/admin/tool/generator/classes/testplan_backend.php b/admin/tool/generator/classes/testplan_backend.php
index 6b3c2e447dd..d4bde532a4a 100644
--- a/admin/tool/generator/classes/testplan_backend.php
+++ b/admin/tool/generator/classes/testplan_backend.php
@@ -100,10 +100,12 @@ class tool_generator_testplan_backend extends tool_generator_backend {
      *
      * @param int $courseid The target course id
      * @param bool $updateuserspassword Updates the course users password to $CFG->tool_generator_users_password
+     * @param int|null $size of the test plan. Used to limit the number of users exported
+     *                 to match the threads in the plan. For BC, defaults to null that means all enrolled users.
      * @return stored_file
      */
-    public static function create_users_file($courseid, $updateuserspassword) {
-        $csvcontents = self::generate_users_file($courseid, $updateuserspassword);
+    public static function create_users_file($courseid, $updateuserspassword, ?int $size = null) {
+        $csvcontents = self::generate_users_file($courseid, $updateuserspassword, $size);
 
         $fs = get_file_storage();
         $filerecord = self::get_file_record('users', 'csv');
@@ -171,14 +173,18 @@ class tool_generator_testplan_backend extends tool_generator_backend {
      *
      * @param int $targetcourseid
      * @param bool $updateuserspassword Updates the course users password to $CFG->tool_generator_users_password
+     * @param int|null $size of the test plan. Used to limit the number of users exported
+     *                 to match the threads in the plan. For BC, defaults to null that means all enrolled users.
      * @return string The users csv file contents.
      */
-    protected static function generate_users_file($targetcourseid, $updateuserspassword) {
+    protected static function generate_users_file($targetcourseid, $updateuserspassword, ?int $size = null) {
         global $CFG;
 
         $coursecontext = context_course::instance($targetcourseid);
 
-        $users = get_enrolled_users($coursecontext, '', 0, 'u.id, u.username, u.auth', 'u.username ASC');
+        // If requested, get the number of users (threads) to use in the plan. We only need those in the exported file.
+        $planusers = self::$users[$size] ?? 0;
+        $users = get_enrolled_users($coursecontext, '', 0, 'u.id, u.username, u.auth', 'u.username ASC', 0, $planusers);
         if (!$users) {
             print_error('coursewithoutusers', 'tool_generator');
         }
diff --git a/admin/tool/generator/cli/maketestplan.php b/admin/tool/generator/cli/maketestplan.php
index 1dbb2ae1498..89a616a68ee 100644
--- a/admin/tool/generator/cli/maketestplan.php
+++ b/admin/tool/generator/cli/maketestplan.php
@@ -98,7 +98,7 @@ if (empty($CFG->tool_generator_users_password) || is_bool($CFG->tool_generator_u
 
 // Create files.
 $courseid = $DB->get_field('course', 'id', array('shortname' => $shortname));
-$usersfile = tool_generator_testplan_backend::create_users_file($courseid, !empty($options['updateuserspassword']));
+$usersfile = tool_generator_testplan_backend::create_users_file($courseid, !empty($options['updateuserspassword']), $size);
 $testplanfile = tool_generator_testplan_backend::create_testplan_file($courseid, $size);
 
 // One file path per line so other CLI scripts can easily parse the output.
diff --git a/admin/tool/generator/maketestplan.php b/admin/tool/generator/maketestplan.php
index fe2965ae225..eac66ea80f1 100644
--- a/admin/tool/generator/maketestplan.php
+++ b/admin/tool/generator/maketestplan.php
@@ -51,7 +51,7 @@ if ($data = $mform->get_data()) {
 
     // Creating both test plan and users files.
     $testplanfile = tool_generator_testplan_backend::create_testplan_file($data->courseid, $data->size);
-    $usersfile = tool_generator_testplan_backend::create_users_file($data->courseid, $data->updateuserspassword);
+    $usersfile = tool_generator_testplan_backend::create_users_file($data->courseid, $data->updateuserspassword, $data->size);
 
     // Test plan link.
     $testplanurl = moodle_url::make_pluginfile_url(
diff --git a/admin/tool/generator/upgrade.txt b/admin/tool/generator/upgrade.txt
index 4d5b19fb4b3..21e87ab3a7f 100644
--- a/admin/tool/generator/upgrade.txt
+++ b/admin/tool/generator/upgrade.txt
@@ -1,6 +1,13 @@
 This files describes API changes in core libraries and APIs,
 information provided here is intended especially for developers.
 
+=== 3.10.8 ===
+
+* Function tool_generator_testplan_backend::create_users_file() now supports to pass the size of the testing plan,
+  that needs to be equal or smaller than the size of the generated site. That's used to effectively restrict the
+  exported number of users to the number of threads the jmeter plan will have (previously all the enrolled users
+  were being exported, with that leading to "false" loops (users not really looping X times).
+
 === 3.7 ===
 
 * Function tool_generator_testplan_backend::get_course_options() is removed, the 'course' form element is used instead.