linux/Documentation/sysctl, branch v2.6.23

handle kernelcore=: generic

2007-07-17T17:22:59Z

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

Add Documentation/sysctl/ctl_unnumbered.txt

2007-07-16T16:05:49Z

Poeple keep on adding new numbered sysctls, when they're supposed not to. Add a documentation file which explain why new sysctls should use CTL_UNNUMBERED. The next patch will sprinkle pointers to this throughout sysctl.c. Eric provided the text (thanks) Cc: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

change zonelist order: zonelist order selection logic

2007-07-16T16:05:35Z

Make zonelist creation policy selectable from sysctl/boot option v6. This patch makes NUMA's zonelist (of pgdat) order selectable. Available order are Default(automatic)/ Node-based / Zone-based. [Default Order] The kernel selects Node-based or Zone-based order automatically. [Node-based Order] This policy treats the locality of memory as the most important parameter. Zonelist order is created by each zone's locality. This means lower zones (ex. ZONE_DMA) can be used before higher zone (ex. ZONE_NORMAL) exhausion. IOW. ZONE_DMA will be in the middle of zonelist. current 2.6.21 kernel uses this. Pros. * A user can expect local memory as much as possible. Cons. * lower zone will be exhansted before higher zone. This may cause OOM_KILL. Maybe suitable if ZONE_DMA is relatively big and you never see OOM_KILL because of ZONE_DMA exhaution and you need the best locality. (example) assume 2 node NUMA. node(0) has ZONE_DMA/ZONE_NORMAL, node(1) has ZONE_NORMAL. *node(0)'s memory allocation order: node(0)'s NORMAL -> node(0)'s DMA -> node(1)'s NORMAL. *node(1)'s memory allocation order: node(1)'s NORMAL -> node(0)'s NORMAL -> node(0)'s DMA. [Zone-based order] This policy treats the zone type as the most important parameter. Zonelist order is created by zone-type order. This means lower zone never be used bofere higher zone exhaustion. IOW. ZONE_DMA will be always at the tail of zonelist. Pros. * OOM_KILL(bacause of lower zone) occurs only if the whole zones are exhausted. Cons. * memory locality may not be best. (example) assume 2 node NUMA. node(0) has ZONE_DMA/ZONE_NORMAL, node(1) has ZONE_NORMAL. *node(0)'s memory allocation order: node(0)'s NORMAL -> node(1)'s NORMAL -> node(0)'s DMA. *node(1)'s memory allocation order: node(1)'s NORMAL -> node(0)'s NORMAL -> node(0)'s DMA. bootoption "numa_zonelist_order=" and proc/sysctl is supporetd. command: %echo N > /proc/sys/vm/numa_zonelist_order Will rebuild zonelist in Node-based order. command: %echo Z > /proc/sys/vm/numa_zonelist_order Will rebuild zonelist in Zone-based order. Thanks to Lee Schermerhorn, he gives me much help and codes. [Lee.Schermerhorn@hp.com: add check_highest_zone to build_zonelists_in_zone_order] [akpm@linux-foundation.org: build fix] Signed-off-by: KAMEZAWA Hiroyuki Cc: Lee Schermerhorn Cc: Christoph Lameter Cc: Andi Kleen Cc: "jesse.barnes@intel.com" Signed-off-by: Lee Schermerhorn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

security: Protection for exploiting null dereference using mmap

2007-07-12T02:52:29Z

Add a new security check on mmap operations to see if the user is attempting to mmap to low area of the address space. The amount of space protected is indicated by the new proc tunable /proc/sys/vm/mmap_min_addr and defaults to 0, preserving existing behavior. This patch uses a new SELinux security class "memprotect." Policy already contains a number of allow rules like a_t self:process * (unconfined_t being one of them) which mean that putting this check in the process class (its best current fit) would make it useless as all user processes, which we also want to protect against, would be allowed. By taking the memprotect name of the new class it will also make it possible for us to move some of the other memory protect permissions out of 'process' and into the new class next time we bump the policy version number (which I also think is a good future idea) Acked-by: Stephen Smalley Acked-by: Chris Wright Signed-off-by: Eric Paris Signed-off-by: James Morris

misc doc and kconfig typos

2007-05-09T06:58:15Z

Fix various typos in kernel docs and Kconfigs, 2.6.21-rc4. Signed-off-by: Matt LaPlante Signed-off-by: Adrian Bunk

Fix misspellings collected by members of KJ list.

2007-05-09T05:14:03Z

Fix the misspellings of "propogate", "writting" and (oh, the shame :-) "kenrel" in the source tree. Signed-off-by: Robert P. J. Day Signed-off-by: Adrian Bunk

mm: fix handling of panic_on_oom when cpusets are in use

2007-05-07T19:12:55Z

The current panic_on_oom may not work if there is a process using cpusets/mempolicy, because other nodes' memory may remain. But some people want failover by panic ASAP even if they are used. This patch makes new setting for its request. This is tested on my ia64 box which has 3 nodes. Signed-off-by: Yasunori Goto Signed-off-by: Benjamin LaHaise Cc: Christoph Lameter Cc: Paul Jackson Cc: Ethan Solomita Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] x86: add sysctl for kstack_depth_to_print

2006-12-07T01:14:11Z

Add sysctl for kstack_depth_to_print. This lets users change the amount of raw stack data printed in dump_stack() without having to reboot. Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Signed-off-by: Andi Kleen

Fix typos in /Documentation : Misc

2006-11-30T04:21:10Z

This patch fixes typos in various Documentation txts. The patch addresses some misc words. Signed-off-by: Matt LaPlante Acked-by: Randy Dunlap Signed-off-by: Adrian Bunk

[PATCH] document the core-dump-to-a-pipe patch

2006-10-11T18:14:22Z

The pipe-a-coredump-to-a-program feature was undocumented. *Grumble*. NB: a good enhancement to that patch would be: save all the stuff that a core file can get from the %x expansions in the environment. Signed-off-by: Matthias Urlichs Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds