Re: [SLUB 2/2] i386 arch page size slab fixes

On Sat, 31 Mar 2007 11:31:07 -0800 (PST) Christoph Lameter <clameter@xxxxxxx> wrote:

Fixup i386 arch for SLUB support

i386 arch code currently uses the page struct of slabs for various purposes.
This interferes with slub and so SLUB has been disabled for i386 by setting
ARCH_USES_SLAB_PAGE_STRUCT.

This patch removes the use of page sized slabs for maintaining pgds and pmds.

Patch by William Irwin with only very minor modifications by me which are

1. Removal of HIGHMEM64G slab caches. It seems that virtualization hosts
require a a full pgd page.

2. Add missing virtualization hook. Seems that we need a new way
of serializing paravirt_alloc(). It may need to do its own serialization.

3. Remove ARCH_USES_SLAB_PAGE_STRUCT

Note that this makes things work without debugging on.
The arch still fails to boot properly if full SLUB debugging is on with
a cryptic message:

CPU: AMD Athlon(tm) 64 Processor 3000+ stepping 00
Checking 'hlt' instruction... OK.
ACPI: Core revision 20070126
ACPI: setting ELCR to 0200 (from 1ca0)
BUG: at kernel/sched.c:3417 sub_preempt_count()
[<c0342d43>] _spin_unlock_irq+0x13/0x30
[<c01160e6>] schedule_tail+0x36/0xd0
[<c0102df8>] __switch_to+0x28/0x180
[<c0103f9a>] ret_from_fork+0x6/0x1c
[<c012acf0>] kthread+0x0/0xe0

This all has the potential to make my inbox hurt.

Can we disable SLUB on i386 in Kconfig until it gets sorted out?
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Relevant Pages

  • [SLUB 2/2] i386 arch page size slab fixes
    ... i386 arch code currently uses the page struct of slabs for various purposes. ... This interferes with slub and so SLUB has been disabled for i386 by setting ... This patch removes the use of page sized slabs for maintaining pgds and pmds. ... pmd_t *pmd; ...
    (Linux-Kernel)
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