如何在codeigniter 3中获取会话数据

I want to get session data in codeigniter I set it successfully but fail to get session data when i print the session data it is empty when i check session data where i set it first it show all the data in the same function but I get same data in anther function data is not showing. Any body help thanks in advance. set session data here

public function user_login()
    {
        $username  =    $this->input->post('user_name');
        $pass      =    $this->input->post('user_password');
        $pass      =    hash('sha1', $pass);

        $array_con = array('emailid' => $username ,'password' => $pass);
        $data = $this->User_model->login($array_con);
        if (!empty($data)) {
        $newdata = array(
        'pkuserid'  => $data->pkuserid,
        'emailid'     => $data->emailid,
        'logged_in' => TRUE
    );
    $this->session->set_userdata($newdata);    
            echo json_encode($data);
        }else
        {
            $data = 0;
            echo json_encode($data);
        }
    }

this is ajax call

if(error=='') {
        var formData = new FormData($('#logged_in')[0]);
        $.ajax({
            type: "POST",
            url: base_url+"profile/user_login",
            data: formData,
            cache:false,
            processData:false,
            contentType:false,

            success: function(data){
                var result = $.parseJSON(data);
                if (result == 0)
                {
                    error = 'Authentication Failed';
                    $("#failed_access").html(error);
                    $("#failed_access").css("display","block");
                    $('#failed_access').delay(5000).fadeOut('slow');

                }else{

                    window.location = base_url+"profile/profile_setup";
                }

            }
        });
    }

this is get session function

public function profile_setup()
    { 
        $email_id = $this->session->userdata('emailid');
        if(!empty($email_id))
        {
            $result['result']    = $this->User_model->profile_data($email_id);
            $user_id                     = $result['result']->pkuserid;

            $this->session->set_userdata('user_id',$user_id);

            $result['countries']         = $this->User_model->get_countries();
            $result['industries']        = $this->User_model->get_industries();
            $result['institution']       = $this->User_model->get_institutions();
            $result['result_companies']  = $this->User_model->get_companies();
            $result['pagetitle']         = 'profile_setup';

            if (!empty($result)) {
                $this->load->view('header/registeruser_header_view');
                $this->load->view("users/profile_view.php", $result);
                $this->load->view('footer/profilesetup');
            }
        }else
        {
            redirect(base_url());
        }
    }

Replace this where you are going to set session in code.

$this->session->set_userdata('logged_in',array(
            'pkuserid'  => $data[0]->pkuserid,
            'emailid' => $data[0]->emailid,
            'logged_in'   => TRUE
        ));

Then change in profile_setup function as below code

$session_data = $this->session->userdata('logged_in');
    $email_id = $session_data['emailid'];