linux-toradex.git/Documentation/atomic_ops.txt, branch v3.10.78

Documentation: Memory barrier semantics of atomic_xchg()

2013-01-08T22:14:55+00:00

Add atomic_xchg() to documentation for atomic operations and
memory barriers.

Signed-off-by: Richard Braun 
Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett

doc: Add load/store guarantees to Documentation/atomic-ops.txt

2011-12-11T18:31:58+00:00

An IRC discussion uncovered many conflicting opinions on what types
of data may be atomically loaded and stored.  This commit therefore
calls this out the official set: pointers, longs, ints, and chars (but
not shorts).  This commit also gives some examples of compiler mischief
that can thwart atomicity.

Please note that this discussion is relevant to !SMP kernels if
CONFIG_PREEMPT=y: preemption can cause almost as much trouble as can SMP.

Signed-off-by: Paul E. McKenney 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Cc: Russell King 
Cc: Haavard Skinnemoen 
Cc: Hans-Christian Egtvedt 
Cc: Mike Frysinger 
Cc: Mikael Starvik 
Cc: Jesper Nilsson 
Cc: David Howells 
Cc: Yoshinori Sato 
Cc: Richard Kuo 
Cc: Jes Sorensen 
Cc: Hirokazu Takata 
Cc: Geert Uytterhoeven 
Cc: Michal Simek 
Cc: Ralf Baechle 
Cc: Koichi Yasutake 
Cc: Jonas Bonn 
Cc: Kyle McMartin 
Cc: Helge Deller 
Cc: "James E.J. Bottomley" 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Chen Liqin 
Cc: Lennox Wu 
Cc: Paul Mundt 
Cc: "David S. Miller" 
Cc: Chris Metcalf 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Cc: Guan Xuetao 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: Chris Zankel

Documentation/atomic_ops.txt: avoid volatile in sample code

2011-05-27T00:12:34+00:00

As declaring counter as volatile is discouraged, it is best not to use it
in sample code as well.

Signed-off-by: Nikanth Karthikesan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Documentation/: it's -> its where appropriate

2010-04-23T00:09:52+00:00

Fix obvious cases of "it's" being used when "its" was meant.

Signed-off-by: Francis Galiegue 
Acked-by: Randy Dunlap 
Signed-off-by: Jiri Kosina

Documentation/atomic_ops.txt: fix sample code

2009-06-17T02:47:52+00:00

list_add() lost a parameter in sample code.

Signed-off-by: Figo.zhang 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

documentation: atomic_add_unless() doesn't imply mb() on failure

2008-02-24T01:52:36+00:00

(sorry for being offtpoic, but while experts are here...)

A "typical" implementation of atomic_add_unless() can return 0 immediately
after the first atomic_read() (before doing cmpxchg). In that case it doesn't
provide any barrier semantics. See include/asm-ia64/atomic.h as an example.

We should either change the implementation, or fix the docs.

Signed-off-by: Oleg Nesterov 
Acked-by: Nick Piggin 
Signed-off-by: Linus Torvalds

bitops: introduce lock ops

2007-10-18T21:37:29+00:00

Introduce test_and_set_bit_lock / clear_bit_unlock bitops with lock semantics.
Convert all architectures to use the generic implementation.

Signed-off-by: Nick Piggin 
Acked-By: David Howells 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Russell King 
Cc: Haavard Skinnemoen 
Cc: Bryan Wu 
Cc: Mikael Starvik 
Cc: David Howells 
Cc: Yoshinori Sato 
Cc: "Luck, Tony" 
Cc: Hirokazu Takata 
Cc: Geert Uytterhoeven 
Cc: Roman Zippel 
Cc: Greg Ungerer 
Cc: Ralf Baechle 
Cc: Kyle McMartin 
Cc: Matthew Wilcox 
Cc: Paul Mackerras 
Cc: Benjamin Herrenschmidt 
Cc: Heiko Carstens 
Cc: Martin Schwidefsky 
Cc: Paul Mundt 
Cc: Kazumoto Kojima 
Cc: Richard Curnow 
Cc: William Lee Irwin III 
Cc: "David S. Miller" 
Cc: Jeff Dike 
Cc: Paolo 'Blaisorblade' Giarrusso 
Cc: Miles Bader 
Cc: Andi Kleen 
Cc: Chris Zankel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

atomic_ops.txt has incorrect, misleading and insufficient information [Bug 9020]

2007-10-17T15:42:58+00:00

atomic_ops.txt has incorrect, misleading and insufficient information about
semantics of initializer, atomic_set, atomic_read and atomic_xchg.

It also incorrectly implies that operations mentioned above are not actual
atomic operations.

Included is most of the patch Document non-semantics of atomic_read() and
atomic_set() by Chris Snook, except the word "assignment".

Signed-off-by: Matti Linnanvuori 
Cc: Nick Piggin 
Cc: "Paul E. McKenney" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

atomic_ops.txt: mention local_t

2007-10-17T15:42:56+00:00

local_t is a variant of atomic_t and has related ops to match.
Add reference for local_t documentation to atomic_ops.txt.

Signed-off-by: Grant Grundler 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Documentation/atomic_ops.txt typo fix

2007-06-09T00:23:33+00:00

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