linux-toradex.git/Documentation/sysctl, branch v2.6.22.15

misc doc and kconfig typos

2007-05-09T06:58:15+00:00

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.

2007-05-09T05:14:03+00:00

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

2007-05-07T19:12:55+00:00

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

2006-12-07T01:14:11+00:00

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

2006-11-30T04:21:10+00:00

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

2006-10-11T18:14:22+00:00

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

[PATCH] zone_reclaim: dynamic slab reclaim

2006-09-26T15:48:51+00:00

Currently one can enable slab reclaim by setting an explicit option in
/proc/sys/vm/zone_reclaim_mode.  Slab reclaim is then used as a final
option if the freeing of unmapped file backed pages is not enough to free
enough pages to allow a local allocation.

However, that means that the slab can grow excessively and that most memory
of a node may be used by slabs.  We have had a case where a machine with
46GB of memory was using 40-42GB for slab.  Zone reclaim was effective in
dealing with pagecache pages.  However, slab reclaim was only done during
global reclaim (which is a bit rare on NUMA systems).

This patch implements slab reclaim during zone reclaim.  Zone reclaim
occurs if there is a danger of an off node allocation.  At that point we

1. Shrink the per node page cache if the number of pagecache
   pages is more than min_unmapped_ratio percent of pages in a zone.

2. Shrink the slab cache if the number of the nodes reclaimable slab pages
   (patch depends on earlier one that implements that counter)
   are more than min_slab_ratio (a new /proc/sys/vm tunable).

The shrinking of the slab cache is a bit problematic since it is not node
specific.  So we simply calculate what point in the slab we want to reach
(current per node slab use minus the number of pages that neeed to be
allocated) and then repeately run the global reclaim until that is
unsuccessful or we have reached the limit.  I hope we will have zone based
slab reclaim at some point which will make that easier.

The default for the min_slab_ratio is 5%

Also remove the slab option from /proc/sys/vm/zone_reclaim_mode.

[akpm@osdl.org: cleanups]
Signed-off-by: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Fix docs for fs.suid_dumpable

2006-08-27T18:01:28+00:00

Sergey Vlasov noticed that there is not kernel.suid_dumpable, but
fs.suid_dumpable.

How KERN_SETUID_DUMPABLE ended up in fs_table[]? Hell knows...

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] doc: update panic_on_oops documentation

2006-08-06T15:57:47+00:00

Signed-off-by: Maxime Bizon 
Acked-by: Simon Horman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] ZVC/zone_reclaim: Leave 1% of unmapped pagecache pages for file I/O

2006-07-03T22:26:59+00:00

It turns out that it is advantageous to leave a small portion of unmapped file
backed pages if all of a zone's pages (or almost all pages) are allocated and
so the page allocator has to go off-node.

This allows recently used file I/O buffers to stay on the node and
reduces the times that zone reclaim is invoked if file I/O occurs
when we run out of memory in a zone.

The problem is that zone reclaim runs too frequently when the page cache is
used for file I/O (read write and therefore unmapped pages!) alone and we have
almost all pages of the zone allocated.  Zone reclaim may remove 32 unmapped
pages.  File I/O will use these pages for the next read/write requests and the
unmapped pages increase.  After the zone has filled up again zone reclaim will
remove it again after only 32 pages.  This cycle is too inefficient and there
are potentially too many zone reclaim cycles.

With the 1% boundary we may still remove all unmapped pages for file I/O in
zone reclaim pass.  However.  it will take a large number of read and writes
to get back to 1% again where we trigger zone reclaim again.

The zone reclaim 2.6.16/17 does not show this behavior because we have a 30
second timeout.

[akpm@osdl.org: rename the /proc file and the variable]
Signed-off-by: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds