On Tue, Oct 16, 2012 at 8:55 PM, Jun Hu <duanshuidao@xxxxxxxxxxx> wrote: > Hi Guys: > > My machine has 8G memory, when I use kernel boot parameter mem=5G , it only > display “4084 M” using “free –m “. > where the “5120-4084 = 1036M “ memory run? mem is misleading parameter. It is not specify amount memoy. It is specify maximum recognized address. Thus when your machine have some memory hole, you see such result. Don't worry, recent regular machine often have ~1G hole. Detailed memory map is logged in /var/log/messages as a part of boot messages. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href