linux-toradex.git/include/linux/kernel.h, branch v3.0.16

BUILD_BUG_ON_ZERO: fix sparse breakage

2011-06-16T03:04:00+00:00

BUILD_BUG_ON_ZERO and BUILD_BUG_ON_NULL must return values, even in the
CHECKER case otherwise various users of it become syntactically invalid.

Signed-off-by: Dr. David Alan Gilbert 
Reviewed-by: KOSAKI Motohiro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lib: add kstrto*_from_user()

2011-05-25T15:39:52+00:00

There is quite a lot of code which does copy_from_user() + strict_strto*()
or simple_strto*() combo in slightly different ways.

Before doing conversions all over tree, let's get final API correct.

Enter kstrtoull_from_user() and friends.

Typical code which uses them looks very simple:

	TYPE val;
	int rv;

	rv = kstrtoTYPE_from_user(buf, count, 0, &val);
	if (rv < 0)
		return rv;
	[use val]
	return count;

There is a tiny semantic difference from the plain kstrto*() API -- the
latter allows any amount of leading zeroes, while the former copies data
into buffer on stack and thus allows leading zeroes as long as it fits
into buffer.

This shouldn't be a problem for typical usecase "echo 42 > /proc/x".

The point is to make reading one integer from userspace _very_ simple and
very bug free.

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

sparse: define dummy BUILD_BUG_ON definition for sparse

2011-05-25T15:39:46+00:00

BUILD_BUG_ON() causes a syntax error to detect coding errors.  So it
causes sparse to detect an error too.  This reduces sparse's usefulness.

This patch makes a dummy BUILD_BUG_ON() definition for sparse.

Signed-off-by: KOSAKI Motohiro 
Cc: Dave Hansen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ftrace: Allow dynamically allocated function tracers

2011-05-18T19:29:51+00:00

Now that functions may be selected individually, it only makes sense
that we should allow dynamically allocated trace structures to
be traced. This will allow perf to allocate a ftrace_ops structure
at runtime and use it to pick and choose which functions that
structure will trace.

Note, a dynamically allocated ftrace_ops will always be called
indirectly instead of being called directly from the mcount in
entry.S. This is because there's no safe way to prevent mcount
from being preempted before calling the function, unless we
modify every entry.S to do so (not likely). Thus, dynamically allocated
functions will now be called by the ftrace_ops_list_func() that
loops through the ops that are allocated if there are more than
one op allocated at a time. This loop is protected with a
preempt_disable.

To determine if an ftrace_ops structure is allocated or not, a new
util function was added to the kernel/extable.c called
core_kernel_data(), which returns 1 if the address is between
_sdata and _edata.

Cc: Paul E. McKenney 
Signed-off-by: Steven Rostedt

kstrto*: converting strings to integers done (hopefully) right

2011-03-23T00:44:14+00:00

1. simple_strto*() do not contain overflow checks and crufty,
   libc way to indicate failure.
2. strict_strto*() also do not have overflow checks but the name and
   comments pretend they do.
3. Both families have only "long long" and "long" variants,
   but users want strtou8()
4. Both "simple" and "strict" prefixes are wrong:
   Simple doesn't exactly say what's so simple, strict should not exist
   because conversion should be strict by default.

The solution is to use "k" prefix and add convertors for more types.
Enter
	kstrtoull()
	kstrtoll()
	kstrtoul()
	kstrtol()
	kstrtouint()
	kstrtoint()

	kstrtou64()
	kstrtos64()
	kstrtou32()
	kstrtos32()
	kstrtou16()
	kstrtos16()
	kstrtou8()
	kstrtos8()

Include runtime testsuite (somewhat incomplete) as well.

strict_strto*() become deprecated, stubbed to kstrto*() and
eventually will be removed altogether.

Use kstrto*() in code today!

Note: on some archs _kstrtoul() and _kstrtol() are left in tree, even if
      they'll be unused at runtime. This is temporarily solution,
      because I don't want to hardcode list of archs where these
      functions aren't needed. Current solution with sizeof() and
      __alignof__ at least always works.

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

kernel.h: fix kernel-doc warning

2011-01-31T22:23:22+00:00

Fix kernel-doc warning in kernel.h from commit 7ef88ad56145
("BUILD_BUG_ON: make it handle more cases"):

  Warning(include/linux/kernel.h:605): No description found for parameter 'condition'
  Warning(include/linux/kernel.h:605): Excess function parameter 'cond' description in 'BUILD_BUG_ON'

Signed-off-by: Randy Dunlap 
Signed-off-by: Linus Torvalds

Remove MAYBE_BUILD_BUG_ON

2011-01-24T04:15:11+00:00

Now BUILD_BUG_ON() can handle optimizable constants, we don't need
MAYBE_BUILD_BUG_ON any more.

Signed-off-by: Rusty Russell

BUILD_BUG_ON: make it handle more cases

2011-01-24T04:15:10+00:00

BUILD_BUG_ON used to use the optimizer to do code elimination or fail
at link time; it was changed to first the size of a negative array (a
nicer compile time error), then (in
8c87df457cb58fe75b9b893007917cf8095660a0) to a bitfield.

This forced us to change some non-constant cases to MAYBE_BUILD_BUG_ON();
as Jan points out in that commit, it didn't work as intended anyway.

bitfields: needs a literal constant at parse time, and can't be put under
	"if (__builtin_constant_p(x))" for example.
negative array: can handle anything, but if the compiler can't tell it's
	a constant, silently has no effect.
link time: breaks link if the compiler can't determine the value, but the
	linker output is not usually as informative as a compiler error.

If we use the negative-array-size method *and* the link time trick,
we get the ability to use BUILD_BUG_ON() under __builtin_constant_p()
branches, and maximal ability for the compiler to detect errors at
build time.

We also document it thoroughly.

Signed-off-by: Rusty Russell 
Cc: Jan Beulich 
Acked-by: Hollis Blanchard

lockdep: Move early boot local IRQ enable/disable status to init/main.c

2011-01-20T12:32:33+00:00

During early boot, local IRQ is disabled until IRQ subsystem is
properly initialized.  During this time, no one should enable
local IRQ and some operations which usually are not allowed with
IRQ disabled, e.g. operations which might sleep or require
communications with other processors, are allowed.

lockdep tracked this with early_boot_irqs_off/on() callbacks.
As other subsystems need this information too, move it to
init/main.c and make it generally available.  While at it,
toggle the boolean to early_boot_irqs_disabled instead of
enabled so that it can be initialized with %false and %true
indicates the exceptional condition.

Signed-off-by: Tejun Heo 
Acked-by: Peter Zijlstra 
Acked-by: Pekka Enberg 
Cc: Linus Torvalds 
LKML-Reference: <20110120110635.GB6036@htj.dyndns.org>
Signed-off-by: Ingo Molnar

mm: vmscan: reclaim order-0 and use compaction instead of lumpy reclaim

2011-01-14T01:32:33+00:00

Lumpy reclaim is disruptive.  It reclaims a large number of pages and
ignores the age of the pages it reclaims.  This can incur significant
stalls and potentially increase the number of major faults.

Compaction has reached the point where it is considered reasonably stable
(meaning it has passed a lot of testing) and is a potential candidate for
displacing lumpy reclaim.  This patch introduces an alternative to lumpy
reclaim whe compaction is available called reclaim/compaction.  The basic
operation is very simple - instead of selecting a contiguous range of
pages to reclaim, a number of order-0 pages are reclaimed and then
compaction is later by either kswapd (compact_zone_order()) or direct
compaction (__alloc_pages_direct_compact()).

[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: use conventional task_struct naming]
Signed-off-by: Mel Gorman 
Cc: Andrea Arcangeli 
Cc: KOSAKI Motohiro 
Cc: Rik van Riel 
Acked-by: Johannes Weiner 
Cc: Andy Whitcroft 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds