linux-kernel - Re: [PATCH v2] x86/kexec: Exclude GART aperture from vmcore

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Message-ID: <20171227122523.GC13909@nazgul.tnic>
Date:   Wed, 27 Dec 2017 13:25:23 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Baoquan He <bhe@...hat.com>
Cc:     Jiri Bohac <jbohac@...e.cz>, Toshi Kani <toshi.kani@....com>,
        David Airlie <airlied@...ux.ie>,
        Dave Young <dyoung@...hat.com>, joro@...tes.org,
        kexec@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Ingo Molnar <mingo@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Bjorn Helgaas <bhelgaas@...gle.com>,
        Thomas Gleixner <tglx@...utronix.de>, yinghai@...nel.org,
        Vivek Goyal <vgoyal@...hat.com>
Subject: Re: [PATCH v2] x86/kexec: Exclude GART aperture from vmcore

On Wed, Dec 27, 2017 at 03:44:49PM +0800, Baoquan He wrote:
> > yes, instead of crashing the machine (because GART may be initialized in the
> > 2nd kernel, overlapping the 1st kernel memory, which the 2nd kernel with its
> > fake e820 map sees as unused).
> > 
> > I'd say this is an improvement.
> 
> I don't get what you said. If 'iommu=off' only specified in 1st kernel,
> kdump kernel will think the memory which GART bar pointed as a hole.
> This is incorrect. I don't see the improvement.

So he says, this memory is unused. Why is that incorrect?!?

Wh do I care about dumping unused memory?!?!

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--