save() and push() are too slow in laravel with white screen result

i have this two related table :

Users --> id | username | password | ...

Users_profiles --> id | user_id | firstname | lastname | ...

My User Eloquent is :

class User extends Authenticatable
{

    protected $fillable = ['username','password','status','type'];

    protected $hidden = [
        'password', 'remember_token',
    ];

    public function profile()
    {
        return $this->hasOne('App\User_profile','user_id', 'id');
    }
}

My User Controller is :

public function Update($id, Request $r){
        $rules = [
            'username'  => 'unique:users,username',
            'firstname' => 'required',
            'lastname'  => 'required',
            'mobile'    => 'required',
        ];
        $validator = \Validator::make($r->all(), $rules);
        if ($validator->fails()) {
            return response()->json(['status' => 'failed', 'message' => $validator->errors()->first()]);
        } else {
            $users = User::with('profile')->where('id',$id)->first();
            $users->username = $r->username;
            $users->profile->firstname = $r->firstname;
            $users->push();
            return response()->json(['status' => 'success', 'message' => "OK"]);
        }
    }

But now when i try to update my record in first it takes long time (about 1 min) and then after update users.username and without changes any thing on users_profile table, appears white screen.

also save() method has this results again.

via Chebli Mohamed