linux-kernel - Re: Why is "Memory split" Kconfig option only for EMBEDDED?

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]

Date:	Wed, 6 Dec 2006 22:00:55 +0100 (MET)
From:	Jan Engelhardt <jengelh@...ux01.gwdg.de>
To:	Norbert Kiesel <nkiesel@...networks.com>
cc:	Arjan van de Ven <arjan@...radead.org>,
	linux-kernel@...r.kernel.org
Subject: Re: Why is "Memory split" Kconfig option only for EMBEDDED?


On Dec 6 2006 14:36, Norbert Kiesel wrote:
>On Wed, 2006-12-06 at 13:45 +0100, Arjan van de Ven wrote:
>> On Wed, 2006-12-06 at 13:19 +0100, Norbert Kiesel wrote:
>> > On Wed, 2006-12-06 at 12:58 +0100, Arjan van de Ven wrote:
>> > > On Wed, 2006-12-06 at 12:42 +0100, Norbert Kiesel wrote:
>> > > > Hi,
>> > > > 
>> > > > I remember reading on LKML some time ago that using
>> > > > VMSPLIT_3G_OPT would be optimal for a machine with
>> > > > exactly 1GB memory (like my current desktop). Why is
>> > > > that option only prompted for after selecting EMBEDDED
>> > > > (which I normally don't select for desktop machines
>> > > 
>> > > because it changes the userspace ABI and has some other
>> > > caveats.... this is not something you should muck with
>> > > lightly
>> > 
>> > Hmm, but it's also marked EXPERIMENTAL. Would that not be
>> > the sufficient?  Assuming I don't use any external/binary
>> > drivers and a self-compiled kernel w//o any additional
>> > patches: is there really any downside?
>> 
>> I said *userspace ABI*. You're changing something that
>> userspace has known about and was documented since the start
>> of Linux. So userspace application binaries can break, and at
>> least you're changing the rules on them. That's fine if you
>> know what you're doing.. but in a general system... not a
>> good default, hence the EMBEDDED.
>
>Thanks for the reply. I was not asking to change the default, I
>just want to see the option in e.g. menuconfig. And the help
>text already has a very strong advise to leave it at
>VMSPLIT_3G.

I have not had yet any problems with VMSPLIT_3G_OPT ever since I
used it -- which dates back to when it was a feature of Con
Kolivas's patchset (known as LOWMEM1G), [even] before it got
merged in mainline.

It only seem to break the VMware compilation process, but what
they do in the makefiles is not really standard anyhow.

>Anyway, I don't want to stress this further: I'm happy enough with my
>Kconfig that has "if EMBEDDED" removed for the prompt. 



	-`J'
-- 
-
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/