mm: meminit: make __early_pfn_to_nid SMP-safe and introduce meminit_pfn_in_nid
authorMel Gorman <mgorman@suse.de>
Tue, 30 Jun 2015 21:56:55 +0000 (14:56 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 1 Jul 2015 02:44:56 +0000 (19:44 -0700)
commit8a942fdea560d4ac0e9d9fabcd5201ad20e0c382
tree452c0f5acccf96ffc54748a44ab5bc788f7dbffc
parentd70ddd7a5d9aa335f9b4b0c3d879e1e70ee1e4e3
mm: meminit: make __early_pfn_to_nid SMP-safe and introduce meminit_pfn_in_nid

__early_pfn_to_nid() use static variables to cache recent lookups as
memblock lookups are very expensive but it assumes that memory
initialisation is single-threaded.  Parallel initialisation of struct
pages will break that assumption so this patch makes __early_pfn_to_nid()
SMP-safe by requiring the caller to cache recent search information.
early_pfn_to_nid() keeps the same interface but is only safe to use early
in boot due to the use of a global static variable.  meminit_pfn_in_nid()
is an SMP-safe version that callers must maintain their own state for.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Tested-by: Nate Zimmer <nzimmer@sgi.com>
Tested-by: Waiman Long <waiman.long@hp.com>
Tested-by: Daniel J Blueman <daniel@numascale.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: Nate Zimmer <nzimmer@sgi.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Waiman Long <waiman.long@hp.com>
Cc: Scott Norton <scott.norton@hp.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/ia64/mm/numa.c
include/linux/mm.h
include/linux/mmzone.h
mm/page_alloc.c