linux-kernel - Re: [PATCH v7 24/27] x86: Add swiotlb force off 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: <50D8E671.3020502@zytor.com>
Date:	Mon, 24 Dec 2012 15:34:09 -0800
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Yinghai Lu <yinghai@...nel.org>
CC:	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...e.hu>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v7 24/27] x86: Add swiotlb force off support

On 12/21/2012 09:11 PM, Yinghai Lu wrote:
> On Fri, Dec 21, 2012 at 7:25 PM, H. Peter Anvin <hpa@...or.com> wrote:
>> On 12/21/2012 07:23 PM, Eric W. Biederman wrote:
>>>
>>> In this case YH has been working on the case of loading a kernel
>>> completely above 4G, and apparently he has also been testing the case of
>>> running a kernel with no memory below 4G.
>>>
>>
>> It is worth noting that we cannot run with *no* memory below 4G -- it is
>> not possible to run SMP at least without some memory below the 1M mark.
> 
> yes need keep 8k or so for trampoline.
> 
> but kdump only use one CPU.
> 

... except we have an active request to change that, and the trampoline
is more like 20K depending on options.

	-hpa


--
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/