From ed7ed365172e27b0efe9d43cc962723c7193e34e Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 17 Jul 2007 04:03:14 -0700 Subject: 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 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 Signed-off-by: Yasunori Goto Acked-by: Andy Whitcroft Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/filesystems/proc.txt | 15 +++++++++++++++ Documentation/kernel-parameters.txt | 16 ++++++++++++++++ Documentation/sysctl/vm.txt | 3 ++- 3 files changed, 33 insertions(+), 1 deletion(-) (limited to 'Documentation') 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 -- cgit v1.2.3-55-g7522