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From: "H. Peter Anvin" <hpa@zytor.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Ondrej Zary <linux@rainbow-software.org>,
	Ingo Molnar <mingo@elte.hu>,
	Yuhong Bao <yuhongbao_386@hotmail.com>,
	linux-kernel@vger.kernel.org, gregkh@suse.de
Subject: Re: Windows side agrees that lowmem corruption is a problem too
Date: Tue, 08 Jun 2010 14:57:53 -0700	[thread overview]
Message-ID: <4C0EBCE1.2070609@zytor.com> (raw)
In-Reply-To: <20100608225656.7f645621@lxorguk.ukuu.org.uk>

On 06/08/2010 02:56 PM, Alan Cox wrote:
>>> I agree that dis-using <1M by default is probably the sanest option.
>>
>> But please limit it to newer systems only (DMI present && year > 200?). There 
>> are many old machines running fine. Losing 1MB from 16MB is a bad thing.
> 
> Losing the low 1MB is bad thing anyway for things like firmware flashing
> and other weird crap that needs low pages (floppy controllers etc).
> 
> Losing 64K (but reporting corruption in it in a big scary way) is
> probably sensible for distributions, but its a config item so its policy
> so that wouldn't be a problem.
> 
> It has to be painful to the vendors so they get complaints, reports and
> support call costs. Otherwise they won't have the correct incentives to
> fix their mess.

We have already functionally lost 64K on all existing machines... I
think the current blacklist covers 90% or more of all systems in
existence, and we keep filling in the few holes that remain.

Adding the remaining half-megabyte of RAM really shouldn't be done
unconditionally, but as I said it could plausibly be reserved for
ZONE_DMA only.

	-hpa


  reply	other threads:[~2010-06-08 21:58 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-06-08 18:28 Windows side agrees that lowmem corruption is a problem too Yuhong Bao
2010-06-08 19:06 ` H. Peter Anvin
2010-06-08 19:08   ` Ingo Molnar
2010-06-08 19:22     ` Ondrej Zary
2010-06-08 19:31       ` Yuhong Bao
2010-06-08 20:31       ` H. Peter Anvin
2010-06-08 20:49         ` Yuhong Bao
2010-06-11  1:15         ` Robert Hancock
2010-06-08 21:56       ` Alan Cox
2010-06-08 21:57         ` H. Peter Anvin [this message]
2010-06-09  1:08           ` Yuhong Bao
  -- strict thread matches above, loose matches on Subject: below --
2010-06-08 18:12 Yuhong Bao

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