linux/arch/x86_64
Andi Kleen 68a3a7feb0 [PATCH] x86_64: Reserve SRAT hotadd memory on x86-64
From: Keith Mannthey, Andi Kleen

Implement memory hotadd without sparsemem. The memory in the SRAT
hotadd area is just preserved instead and can be activated later.

There are a few restrictions:
- Only one continuous hotadd area allowed per node

The main problem is dealing with the many buggy SRAT tables
that are out there. The strategy here is to reject anything
suspicious.

Originally from Keith Mannthey, with several hacks and changes by AK
and also contributions from Andrew Morton

[ TBD: Problems pointed out by KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>:

 1) Goto's rebuild_zonelist patch will not work if CONFIG_MEMORY_HOTPLUG=n.

    Rebuilding zonelist is necessary when the system has just memory <
    4G at boot, and hot add memory > 4G.  because x86_64 has DMA32,
    ZONE_NORAML is not included into zonelist at boot time if system
    doesn't have memory >4G at boot.

    [AK: should just force the higher zones at boot time when SRAT tells us]

 2) zone and node's spanned_pages and present_pages are not incremented.
    They should be.

    For example, our server (ia64/Fujitsu PrimeQuest) can equip memory
    from 4G to 1T(maybe 2T in future), and SRAT will *always* say we have
    possible 1T +memory.  (Microsoft requires "write all possible memory
    in SRAT") When we reserve memmap for possible 1T memory, Linux will
    not work well in +minimum 4G configuraion ;)

    [AK: needs limiting to 5-10% of max memory]
 ]

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-09 11:53:16 -07:00
..
boot [PATCH] x86: "make isoimage" support; FDINITRD= support; minor cleanups 2006-03-26 08:56:53 -08:00
crypto [CRYPTO] aes: Fixed array boundary violation 2006-03-21 20:14:10 +11:00
ia32 [PATCH] Mark unwind info for signal trampolines in vDSOs 2006-03-31 12:18:52 -08:00
kernel [PATCH] x86_64: Support memory hotadd without sparsemem 2006-04-09 11:53:16 -07:00
lib [PATCH] x86_64: remove dead do_softirq_thunk 2006-03-25 09:10:53 -08:00
mm [PATCH] x86_64: Reserve SRAT hotadd memory on x86-64 2006-04-09 11:53:16 -07:00
oprofile [PATCH] Move Kprobes and Oprofile to "Instrumentation Support" menu 2005-11-07 07:53:35 -08:00
pci [PATCH] x86_64: {set,clear,test}_bit() related cleanup and pci_mmcfg_init() fix 2006-03-24 07:33:15 -08:00
defconfig [PATCH] x86_64: Update defconfig 2006-04-09 11:53:16 -07:00
Kconfig [PATCH] unify pfn_to_page: x86_64 pfn_to_page 2006-03-27 08:44:44 -08:00
Kconfig.debug [PATCH] x86_64: Remove CONFIG_INIT_DEBUG 2006-02-04 16:43:13 -08:00
Makefile [PATCH] x86: "make isoimage" support; FDINITRD= support; minor cleanups 2006-03-26 08:56:53 -08:00