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Commit ed7ed365 authored by Mel Gorman's avatar Mel Gorman Committed by Linus Torvalds
Browse files

handle kernelcore=: generic 



This patch adds the kernelcore= parameter for x86.

Once all patches are applied, a new command-line parameter exist and a new
sysctl.  This patch adds the necessary documentation.

From: Yasunori Goto <y-goto@jp.fujitsu.com>

  When "kernelcore" boot option is specified, kernel can't boot up on ia64
  because of an infinite loop.  In addition, the parsing code can be handled
  in an architecture-independent manner.

  This patch uses common code to handle the kernelcore= parameter.  It is
  only available to architectures that support arch-independent zone-sizing
  (i.e.  define CONFIG_ARCH_POPULATES_NODE_MAP).  Other architectures will
  ignore the boot parameter.

[bunk@stusta.de: make cmdline_parse_kernelcore() static]
Signed-off-by: default avatarMel Gorman <mel@csn.ul.ie>
Signed-off-by: default avatarYasunori Goto <y-goto@jp.fujitsu.com>
Acked-by: default avatarAndy Whitcroft <apw@shadowen.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 396faf03

Documentation/filesystems/proc.txt

+15 −0
Original line number Diff line number Diff line
@@ -1348,6 +1348,21 @@ nr_hugepages configures number of hugetlb page reserved for the system. 
hugetlb_shm_group contains group id that is allowed to create SysV shared

memory segment using hugetlb page.



hugepages_treat_as_movable

--------------------------



This parameter is only useful when kernelcore= is specified at boot time to

create ZONE_MOVABLE for pages that may be reclaimed or migrated. Huge pages

are not movable so are not normally allocated from ZONE_MOVABLE. A non-zero

value written to hugepages_treat_as_movable allows huge pages to be allocated

from ZONE_MOVABLE.



Once enabled, the ZONE_MOVABLE is treated as an area of memory the huge

pages pool can easily grow or shrink within. Assuming that applications are

not running that mlock() a lot of memory, it is likely the huge pages pool

can grow to the size of ZONE_MOVABLE by repeatedly entering the desired value

into nr_hugepages and triggering page reclaim.



laptop_mode

-----------

Documentation/kernel-parameters.txt

+16 −0
Original line number Diff line number Diff line
@@ -817,6 +817,22 @@ and is between 256 and 4096 characters. It is defined in the file 
	js=		[HW,JOY] Analog joystick

			See Documentation/input/joystick.txt.



	kernelcore=nn[KMG]	[KNL,IA-32,IA-64,PPC,X86-64] This parameter

			specifies the amount of memory usable by the kernel

			for non-movable allocations.  The requested amount is

			spread evenly throughout all nodes in the system. The

			remaining memory in each node is used for Movable

			pages. In the event, a node is too small to have both

			kernelcore and Movable pages, kernelcore pages will

			take priority and other nodes will have a larger number

			of kernelcore pages.  The Movable zone is used for the

			allocation of pages that may be reclaimed or moved

			by the page migration subsystem.  This means that

			HugeTLB pages may not be allocated from this zone.

			Note that allocations like PTEs-from-HighMem still

			use the HighMem zone if it exists, and the Normal

			zone if it does not.



	keepinitrd	[HW,ARM]



	kstack=N	[IA-32,X86-64] Print N words from the kernel stack

Documentation/sysctl/vm.txt

+2 −1
Original line number Diff line number Diff line
@@ -38,7 +38,8 @@ Currently, these files are in /proc/sys/vm: 


dirty_ratio, dirty_background_ratio, dirty_expire_centisecs,

dirty_writeback_centisecs, vfs_cache_pressure, laptop_mode,

block_dump, swap_token_timeout, drop-caches:

block_dump, swap_token_timeout, drop-caches,

hugepages_treat_as_movable:



See Documentation/filesystems/proc.txt

arch/ia64/kernel/efi.c

+1 −0
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <linux/time.h>

#include <linux/efi.h>

#include <linux/kexec.h>

#include <linux/mm.h>



#include <asm/io.h>

#include <asm/kregs.h>

include/linux/mm.h

+0 −1
Original line number Diff line number Diff line
@@ -1005,7 +1005,6 @@ extern unsigned long find_max_pfn_with_active_regions(void); 
extern void free_bootmem_with_active_regions(int nid,

						unsigned long max_low_pfn);

extern void sparse_memory_present_with_active_regions(int nid);

extern int cmdline_parse_kernelcore(char *p);

#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID

extern int early_pfn_to_nid(unsigned long pfn);

#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */