Re: [tip:core/memblock] x86-64: Only set max_pfn_mapped to 512 MiBif we enter via head_64.S

From: Ingo Molnar
Date: Thu Oct 14 2010 - 02:37:25 EST



* Yinghai Lu <yinghai@xxxxxxxxxx> wrote:

> On 10/13/2010 10:57 PM, Ingo Molnar wrote:
> >
> > * tip-bot for Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:
> >
> >> Commit-ID: 859ee4f57fb4e91de8439496f62eb996f4a28ca8
> >> Gitweb: http://git.kernel.org/tip/859ee4f57fb4e91de8439496f62eb996f4a28ca8
> >> Author: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
> >> AuthorDate: Wed, 13 Oct 2010 16:34:15 -0700
> >> Committer: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
> >> CommitDate: Wed, 13 Oct 2010 17:09:59 -0700
> >>
> >> x86-64: Only set max_pfn_mapped to 512 MiB if we enter via head_64.S
> >>
> >> head_64.S maps up to 512 MiB, but that is not necessarity true for
> >> other entry paths, such as Xen.
> >
> > These two commits are a boot crasher on x86 defconfig (64-bit):
> >
> > [ 0.000000] init_memory_mapping: 0000000000000000-000000003fff0000
> > [ 0.000000] 0000000000 - 003fe00000 page 2M
> > [ 0.000000] 003fe00000 - 003fff0000 page 4k
> > [ 0.000000] Kernel panic - not syncing: Cannot find space for the kernel page tables
> > [ 0.000000] Pid: 0, comm: swapper Not tainted 2.6.36-rc7-tip+ #49192
> > [ 0.000000] Call Trace:
> > [ 0.000000] [<ffffffff8156c73f>] panic+0x8c/0x192
> > [ 0.000000] [<ffffffff8156c881>] ? printk+0x3c/0x3e
> > [ 0.000000] [<ffffffff8154ec40>] init_memory_mapping+0x372/0x506
> > [ 0.000000] [<ffffffff819053ed>] ? memblock_x86_reserve_range+0x7c/0x83
> > [ 0.000000] [<ffffffff818f2f3d>] setup_arch+0x5a3/0xa68
> > [ 0.000000] [<ffffffff8156c881>] ? printk+0x3c/0x3e
> > [ 0.000000] [<ffffffff81061135>] ? clockevents_register_notifier+0x3e/0x4a
> > [ 0.000000] [<ffffffff818ef9e1>] start_kernel+0x83/0x36e
> > [ 0.000000] [<ffffffff818ef2a8>] x86_64_start_reservations+0xb8/0xbc
> > [ 0.000000] [<ffffffff818ef393>] x86_64_start_kernel+0xe7/0xee
>
> max_pfn_mapped is in .bss section. so it get cleared.
>
> will have a patch to move clear_bss from head64.c to head_64.S

Ok, great - thanks!

Ingo
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