linux-kernel - Re: Does Linux have plan to support memory hole remapping?

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <ac8af0be0804090204t79beaca2qe077a28fc4a515ad@mail.gmail.com>
Date:	Wed, 9 Apr 2008 17:04:24 +0800
From:	"Zhao Forrest" <forrest.zhao@...il.com>
To:	"Andi Kleen" <andi@...stfloor.org>
Cc:	discuss@...-64.org, linux-kernel@...r.kernel.org,
	yhlu.kernel@...il.com, mingo@...e.hu, ak@...e.de
Subject: Re: Does Linux have plan to support memory hole remapping?

On 4/9/08, Andi Kleen <andi@...stfloor.org> wrote:
> "Zhao Forrest" <forrest.zhao@...il.com> writes:
> >
> > As we can see from above information that the physical memory in system
> > is 32768MB(32GB). However OS is only using about
> > (32768-512)MB(MemTotal:     33010240 kB). Does this mean that this
> > linux kernel can't use the physical memory remapped
> > from (4G-512M, 4G) to (32G, 32G+512M)?
>
> The linux kernel can only use the memory passed to it by the BIOS.
> Sometimes they need special BIOS setup options to enable remapping. If
> there are no such options and you can't upgrade it you're out of luck

Yes, I have enabled mem hole remapping in BIOS SETUP.
After looking into dmesg, I found that all 32GB physical memory has
been allocated to 8 nodes, but why MemTotal shows a less amount of
memory than 32GB? Interesting......
Does MemTotal means the amount of physical memory allocated to all
nodes? Or it has different meanings?

Thanks,
Forrest
--
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/