linux-kernel - Re: [PATCH] x86: 46 bit PAE support

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: <20090506123030.GW25203@elte.hu>
Date:	Wed, 6 May 2009 14:30:30 +0200
From:	Ingo Molnar <mingo@...e.hu>
To:	Rik van Riel <riel@...hat.com>
Cc:	"H. Peter Anvin" <hpa@...or.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	linux-mm@...ck.org, mingo@...hat.com, akpm@...ux-foundation.org
Subject: Re: [PATCH] x86: 46 bit PAE support


* Rik van Riel <riel@...hat.com> wrote:

> H. Peter Anvin wrote:
>> Rik van Riel wrote:
>>> Testing: booted it on an x86-64 system with 6GB RAM.  Did you really think
>>> I had access to a system with 64TB of RAM? :)
>>
>> No, but it would be good if we could test it under Qemu or KVM with an
>> appropriately set up sparse memory map.
>
> I don't have a system with 1TB either, which is how much space
> the memmap[] would take...

Not if the physical layout is sparse. I.e. something silly like:

  BIOS-e820: 0000000100000000 - 0000000140000000 (usable)
  BIOS-e820: 0000200000000000 - 0000200040000000 (usable)

Which is 1GB of RAM at 4GB physical offset, and another 1GB of RAM 
at 32 TB physical offset. Takes two gigs of real RAM and a kernel 
modified with your patch, to not get confused by this :-)

	Ingo
--
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/