[tip:locking/core] locking/Documentation: Fix incorrect example code

From: tip-bot for SeongJae Park
Date: Tue May 15 2018 - 02:25:30 EST


Commit-ID: fc7bdc90249b216051d06496577c306327f2e3f5
Gitweb: https://git.kernel.org/tip/fc7bdc90249b216051d06496577c306327f2e3f5
Author: SeongJae Park <sj38.park@xxxxxxxxx>
AuthorDate: Mon, 14 May 2018 15:55:32 -0700
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 15 May 2018 08:11:14 +0200

locking/Documentation: Fix incorrect example code

- Remove a stale line of code
- Fix the condition of the READ_ONCE() example

Signed-off-by: SeongJae Park <sj38.park@xxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: akiyks@xxxxxxxxx
Cc: boqun.feng@xxxxxxxxx
Cc: dhowells@xxxxxxxxxx
Cc: j.alglave@xxxxxxxxx
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: luc.maranget@xxxxxxxx
Cc: npiggin@xxxxxxxxx
Cc: parri.andrea@xxxxxxxxx
Link: http://lkml.kernel.org/r/1526338533-6044-7-git-send-email-paulmck@xxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
Documentation/core-api/atomic_ops.rst | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Documentation/core-api/atomic_ops.rst b/Documentation/core-api/atomic_ops.rst
index fce929144ccd..4ea4af71e68a 100644
--- a/Documentation/core-api/atomic_ops.rst
+++ b/Documentation/core-api/atomic_ops.rst
@@ -111,7 +111,6 @@ If the compiler can prove that do_something() does not store to the
variable a, then the compiler is within its rights transforming this to
the following::

- tmp = a;
if (a > 0)
for (;;)
do_something();
@@ -119,7 +118,7 @@ the following::
If you don't want the compiler to do this (and you probably don't), then
you should use something like the following::

- while (READ_ONCE(a) < 0)
+ while (READ_ONCE(a) > 0)
do_something();

Alternatively, you could place a barrier() call in the loop.