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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)
tree6c22daf6908f92c64aae2b425e6383fe0ed404ac /Documentation
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>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/filesystems/proc.txt15
-rw-r--r--Documentation/kernel-parameters.txt16
-rw-r--r--Documentation/sysctl/vm.txt3
3 files changed, 33 insertions, 1 deletions
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 460b892d089e..ebffdffb3d99 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.
+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
-----------
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 8363ad3ba018..1794affbd06f 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 df3ff2095f9d..a0ccc5b60260 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,
+hugepages_treat_as_movable:
See Documentation/filesystems/proc.txt