diff options
authorMel Gorman <mel@csn.ul.ie>2007-07-17 04:03:14 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-17 10:22:59 -0700
commited7ed365172e27b0efe9d43cc962723c7193e34e (patch)
parent396faf0303d273219db5d7eb4a2879ad977ed185 (diff)
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: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Acked-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
6 files changed, 38 insertions, 3 deletions
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 460b892d089..ebffdffb3d9 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -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.
+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
+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.
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 8363ad3ba01..1794affbd06 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -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
diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt
index df3ff2095f9..a0ccc5b6026 100644
--- a/Documentation/sysctl/vm.txt
+++ b/Documentation/sysctl/vm.txt
@@ -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,
See Documentation/filesystems/proc.txt
diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c
index 75ec3478d8a..73ca86d0381 100644
--- a/arch/ia64/kernel/efi.c
+++ b/arch/ia64/kernel/efi.c
@@ -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>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 857e4481717..97d0cddfd22 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -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);
extern int early_pfn_to_nid(unsigned long pfn);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c3f6f851f76..0a53728a12f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3416,7 +3416,7 @@ void __init free_area_init_nodes(unsigned long *max_zone_pfn)
* kernelcore=size sets the amount of memory for use for allocations that
* cannot be reclaimed or migrated.
-int __init cmdline_parse_kernelcore(char *p)
+static int __init cmdline_parse_kernelcore(char *p)
unsigned long long coremem;
if (!p)
@@ -3430,6 +3430,9 @@ int __init cmdline_parse_kernelcore(char *p)
return 0;
+early_param("kernelcore", cmdline_parse_kernelcore);