linux-toradex.git/Documentation/memory-barriers.txt, branch v3.18.18

memory-barriers: Fix description of 2-legged-if-based control dependencies

2014-09-07T23:15:53+00:00

Sad to say, current compilers really will hoist identical stores from both
branches of an "if" statement to precede the conditional.  This commit
therefore updates the description of control dependencies to reflect this
ugly reality.

Reported-by: Pranith Kumar 
Reported-by: Peter Zijlstra 
Signed-off-by: Paul E. McKenney

memory-barriers: Retain barrier() in fold-to-zero example

2014-09-07T23:15:52+00:00

The transformation in the fold-to-zero example incorrectly omits the
barrier() directive.  This commit therefore adds it back in.

Reported-by: Pranith Kumar 
Signed-off-by: Paul E. McKenney

memory-barriers: Fix control-ordering no-transitivity example

2014-09-07T23:15:41+00:00

The control-ordering example demonstrating lack of transitivity had
multiple problems.  This commit fixes them.

Reported-by: Nikolay Samofatov 
Signed-off-by: Paul E. McKenney 
Reviewed-by: Pranith Kumar

documentation: Add acquire/release barriers to pairing rules

2014-07-08T15:32:51+00:00

It is possible to pair acquire and release barriers with other barriers,
so this commit adds them to the list in the SMP barrier pairing section.

Reported-by: Lai Jiangshan 
Signed-off-by: Paul E. McKenney 
Reviewed-by: Tejun Heo 
Reviewed-by: Josh Triplett 
[ paulmck: Updated pairing discussion as suggested by Peter Zijlstra. ]

documentation: Clarify wake-up/memory-barrier relationship

2014-07-08T15:13:03+00:00

This commit adds an example demonstrating that if a wake_up() doesn't
actually wake something up, no memory ordering is provided.

Reported-by: Peter Zijlstra 
Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett 
Reviewed-by: Lai Jiangshan 
Acked-by: Peter Zijlstra

Documentation/memory-barriers.txt: fix important typo re memory barriers

2014-06-06T23:08:11+00:00

Examples introducing neccesity of RMB+WMP pair reads as

        A=3	READ B
        www	rrrrrr
        B=4	READ A

Note the opposite order of reads vs writes.

But the first example without barriers reads as

        A=3	READ A
        B=4	READ B

There are 4 outcomes in the first example.

But if someone new to the concept tries to insert barriers like this:

        A=3	READ A
        www	rrrrrr
        B=4	READ B

he will still get all 4 possible outcomes, because "READ A" is first.

All this can be utterly confusing because barrier pair seems to be
superfluous.  In short, fixup first example to match latter examples
with barriers.

Signed-off-by: Alexey Dobriyan 
Cc: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

arch,doc: Convert smp_mb__*()

2014-04-18T12:20:48+00:00

Update the documentation to reflect the change of barrier primitives.

Signed-off-by: Peter Zijlstra 
Reviewed-by: Paul E. McKenney 
Acked-by: David Howells 
Link: http://lkml.kernel.org/n/tip-xslfehiga1twbk5uk94rij1e@git.kernel.org
Cc: Linus Torvalds 
Cc: Randy Dunlap 
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial

2014-04-02T23:23:38+00:00

Pull trivial tree updates from Jiri Kosina:
 "Usual rocket science -- mostly documentation and comment updates"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
  sparse: fix comment
  doc: fix double words
  isdn: capi: fix "CAPI_VERSION" comment
  doc: DocBook: Fix typos in xml and template file
  Bluetooth: add module name for btwilink
  driver core: unexport static function create_syslog_header
  mmc: core: typo fix in printk specifier
  ARM: spear: clean up editing mistake
  net-sysfs: fix comment typo 'CONFIG_SYFS'
  doc: Insert MODULE_ in module-signing macros
  Documentation: update URL to hfsplus Technote 1150
  gpio: update path to documentation
  ixgbe: Fix format string in ixgbe_fcoe.
  Kconfig: Remove useless "default N" lines
  user_namespace.c: Remove duplicated word in comment
  CREDITS: fix formatting
  treewide: Fix typo in Documentation/DocBook
  mm: Fix warning on make htmldocs caused by slab.c
  ata: ata-samsung_cf: cleanup in header file
  idr: remove unused prototype of idr_free()

doc: fix double words

2014-03-21T12:16:58+00:00

Fix double words "the the" in various files
within Documentations.

Signed-off-by: Masanari Iida 
Signed-off-by: Jiri Kosina

Documentation/memory-barriers.txt: Clarify release/acquire ordering

2014-02-24T16:37:29+00:00

This commit fixes a couple of typos and clarifies what happens when
the CPU chooses to execute a later lock acquisition before a prior
lock release, in particular, why deadlock is avoided.

Reported-by: Peter Hurley 
Reported-by: James Bottomley 
Reported-by: Stefan Richter 
Signed-off-by: Paul E. McKenney