linux-toradex.git/kernel/sysctl.c, branch tegra-9.12.7

security: use mmap_min_addr indepedently of security models

2009-08-13T22:06:08+00:00

This patch removes the dependency of mmap_min_addr on CONFIG_SECURITY.
It also sets a default mmap_min_addr of 4096.

mmapping of addresses below 4096 will only be possible for processes
with CAP_SYS_RAWIO.

Signed-off-by: Christoph Lameter 
Acked-by: Eric Paris 
Looks-ok-by: Linus Torvalds 
Signed-off-by: James Morris

mm: Add min_free_order_shift tunable.

2009-04-07T23:42:54+00:00

By default the kernel tries to keep half as much memory free at each
order as it does for one order below. This can be too agressive when
running without swap.

Signed-off-by: Arve Hjønnevåg

mm: fix dirty_bytes/dirty_background_bytes sysctls on 64bit arches

2009-02-11T22:25:35+00:00

We need to pass an unsigned long as the minimum, because it gets casted
to an unsigned long in the sysctl handler. If we pass an int, we'll
access four more bytes on 64bit arches, resulting in a random minimum
value.

[rientjes@google.com: fix type of `old_bytes']
Signed-off-by: Sven Wegener 
Cc: Peter Zijlstra 
Cc: Dave Chinner 
Cc: Christoph Lameter 
Cc: David Rientjes 
Signed-off-by: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'core/debugobjects' into core/urgent

2009-01-22T09:03:02+00:00

[IA64] dump stack on kernel unaligned warnings

2009-01-15T18:38:56+00:00

Often the cause of kernel unaligned access warnings is not
obvious from just the ip displayed in the warning.  This adds
the option via proc to dump the stack in addition to the warning.
The default is off (just display the 1 line warning).  To enable
the stack to be shown: echo 1 > /proc/sys/kernel/unaligned-dump-stack

Signed-off-by: Doug Chapman 
Signed-off-by: Tony Luck

[CVE-2009-0029] System call wrappers part 27

2009-01-14T13:15:29+00:00

Signed-off-by: Heiko Carstens

softlock: fix false panic which can occur if softlockup_thresh is reduced

2009-01-14T10:48:07+00:00

At run-time, if softlockup_thresh is changed to a much lower value,
touch_timestamp is likely to be much older than the new softlock_thresh.

This will cause a false softlockup to be detected. If softlockup_panic
is enabled, the system will panic.

The fix is to touch all watchdogs before changing softlockup_thresh.

Signed-off-by: Mandeep Singh Baines 
Signed-off-by: Ingo Molnar

NOMMU: Make mmap allocation page trimming behaviour configurable.

2009-01-08T12:04:47+00:00

NOMMU mmap allocates a piece of memory for an mmap that's rounded up in size to
the nearest power-of-2 number of pages.  Currently it then discards the excess
pages back to the page allocator, making that memory available for use by other
things.  This can, however, cause greater amount of fragmentation.

To counter this, a sysctl is added in order to fine-tune the trimming
behaviour.  The default behaviour remains to trim pages aggressively, while
this can either be disabled completely or set to a higher page-granular
watermark in order to have finer-grained control.

vm region vm_top bits taken from an earlier patch by David Howells.

Signed-off-by: Paul Mundt 
Signed-off-by: David Howells 
Tested-by: Mike Frysinger

mm: add dirty_background_bytes and dirty_bytes sysctls

2009-01-06T23:59:03+00:00

This change introduces two new sysctls to /proc/sys/vm:
dirty_background_bytes and dirty_bytes.

dirty_background_bytes is the counterpart to dirty_background_ratio and
dirty_bytes is the counterpart to dirty_ratio.

With growing memory capacities of individual machines, it's no longer
sufficient to specify dirty thresholds as a percentage of the amount of
dirtyable memory over the entire system.

dirty_background_bytes and dirty_bytes specify quantities of memory, in
bytes, that represent the dirty limits for the entire system.  If either
of these values is set, its value represents the amount of dirty memory
that is needed to commence either background or direct writeback.

When a `bytes' or `ratio' file is written, its counterpart becomes a
function of the written value.  For example, if dirty_bytes is written to
be 8096, 8K of memory is required to commence direct writeback.
dirty_ratio is then functionally equivalent to 8K / the amount of
dirtyable memory:

	dirtyable_memory = free pages + mapped pages + file cache

	dirty_background_bytes = dirty_background_ratio * dirtyable_memory
		-or-
	dirty_background_ratio = dirty_background_bytes / dirtyable_memory

		AND

	dirty_bytes = dirty_ratio * dirtyable_memory
		-or-
	dirty_ratio = dirty_bytes / dirtyable_memory

Only one of dirty_background_bytes and dirty_background_ratio may be
specified at a time, and only one of dirty_bytes and dirty_ratio may be
specified.  When one sysctl is written, the other appears as 0 when read.

The `bytes' files operate on a page size granularity since dirty limits
are compared with ZVC values, which are in page units.

Prior to this change, the minimum dirty_ratio was 5 as implemented by
get_dirty_limits() although /proc/sys/vm/dirty_ratio would show any user
written value between 0 and 100.  This restriction is maintained, but
dirty_bytes has a lower limit of only one page.

Also prior to this change, the dirty_background_ratio could not equal or
exceed dirty_ratio.  This restriction is maintained in addition to
restricting dirty_background_bytes.  If either background threshold equals
or exceeds that of the dirty threshold, it is implicitly set to half the
dirty threshold.

Acked-by: Peter Zijlstra 
Cc: Dave Chinner 
Cc: Christoph Lameter 
Signed-off-by: David Rientjes 
Cc: Andrea Righi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6

2008-12-29T04:19:47+00:00

Conflicts:
	arch/sparc64/kernel/idprom.c