From mboxrd@z Thu Jan  1 00:00:00 1970
From: damian.tometzki@icloud.com (Damian Tometzki)
Date: Tue, 12 Dec 2017 21:18:24 +0100
Subject: Virtual Memory Map
Message-ID: <20171212201824.GA18390@zrhn9910b>
To: kernelnewbies@lists.kernelnewbies.org
List-Id: kernelnewbies.lists.kernelnewbies.org

Hello all,

i have a short question:

How are the bits (in brackets) calculated in the virtual memory map ?

for example the first line (=47 bits)

Virtual memory map with 4 level page tables:

0000000000000000 - 00007fffffffffff (=47 bits) user space, different per mm
hole caused by [47:63] sign extension
ffff800000000000 - ffff87ffffffffff (=43 bits) guard hole, reserved for hypervisor

Best regards
Damian