remove admin bar globally on front and back end

admin-bar-kill.php

<?php
add_action  ( 'init',  'rkv_adminbar_front_kill' );
add_action	( 'admin_init',  'rkv_adminbar_back_kill' );

function rkv_adminbar_front_kill() {

	show_admin_bar( false );
	wp_dequeue_script('admin-bar');
	wp_dequeue_style('admin-bar');

	add_filter('wp_head',  'rkv_admin_front_style_kill', 99 );
	add_filter('admin_head',  'rkv_admin_back_style_kill', 99 );

}


function rkv_adminbar_back_kill() {

	show_admin_bar( false );
	wp_dequeue_script('admin-bar');
	wp_dequeue_style('admin-bar');

	add_filter('admin_head',  'rkv_admin_back_style_kill', 99 );

}

function rkv_admin_front_style_kill() {
	echo '<style type="text/css" media="screen">
			html { margin-top: 0px !important; }
			* html body { margin-top: 0px !important; }
			</style>';
}

function rkv_admin_back_style_kill() {
	echo '<style type="text/css" media="screen">
			html.wp-toolbar { margin-top: 0px !important; padding-top: 0px !important; }
			div#wpadminbar {display:none!important;}
			</style>';
}