linux-kernel - Re: memory beyond4GB invisible to the system even though CONFIG

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <adaeiz6k4o4.fsf@cisco.com>
Date:	Tue, 13 Jan 2009 18:22:19 -0800
From:	Roland Dreier <rdreier@...co.com>
To:	"James Kirin" <james.kirin40@...il.com>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: memory beyond4GB invisible to the system even though CONFIG_HIGHMEM64G=y

 > I am running kernel 2.6.28 on a computer with 8GB RAM. The BIOS
 > detects all 8GB, yet
 > 
 > jk@...2:~$ free
 >              total       used       free     shared    buffers     cached
 > Mem:       3622504     799696    2822808          0      90936     369604
 > -/+ buffers/cache:     339156    3283348
 > Swap:      6867776          0    6867776

The message in your kernel log:

[    0.000000] WARNING: BIOS bug: CPU MTRRs don't cover all of memory, losing 4096MB of RAM.
[    0.000000] ------------[ cut here ]------------
[    0.000000] WARNING: at arch/x86/kernel/cpu/mtrr/main.c:1662 mtrr_trim_uncached_memory+0x283/0x2a4()

is a clue.  You might want to look for a BIOS update for your
motherboard.

 - R.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/