Re: [GIT PULL] x86/uapi for 3.8

From: Linus Torvalds
Date: Sat Dec 15 2012 - 14:58:11 EST


On Sat, Dec 15, 2012 at 11:41 AM, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
>
> Matt is on vacation, and I'm partly offline for the weekend, but that
> definitely seems suspicious. Do we have a memory map of the affected
> machine(s)?

Here's mine.

e820: BIOS-provided physical RAM map:
BIOS-e820: [mem 0x0000000000000000-0x000000000009e7ff] usable
BIOS-e820: [mem 0x000000000009e800-0x000000000009ffff] reserved
BIOS-e820: [mem 0x00000000000e4000-0x00000000000fffff] reserved
BIOS-e820: [mem 0x0000000000100000-0x00000000bdc6ffff] usable
BIOS-e820: [mem 0x00000000bdc70000-0x00000000bdc87fff] ACPI data
BIOS-e820: [mem 0x00000000bdc88000-0x00000000bdcdbfff] ACPI NVS
BIOS-e820: [mem 0x00000000bdcdc000-0x00000000bfffffff] reserved
BIOS-e820: [mem 0x00000000fee00000-0x00000000fee00fff] reserved
BIOS-e820: [mem 0x00000000ff800000-0x00000000ffffffff] reserved
BIOS-e820: [mem 0x0000000100000000-0x00000001fbffffff] usable
BIOS-e820: [mem 0x00000001fc000000-0x00000001ffffffff] reserved
BIOS-e820: [mem 0x0000000200000000-0x000000023fffffff] usable

but as mentioned, there's bound to be some particular kernel layout
that triggers this, because I definitely ran a few kernels with that
commit in it without problems (and clearly other people are too).
Looking at my boot log, I had successful boots with both 6a57d104c8cb
and c2714334b944, which contains that commit.

It might also be that it causes some massive corruption at boot time,
but it then requires that that particular memory is actually used. So
maybe it's not so much about the memory map except indirectly.

But that commit *does* look a lot more likely than the things I looked at.

Markus, how did you happen to pinpoint that particular commit? Is it
entirely repeatable for you?

Linus
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