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From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
	mingo@kernel.org
Cc: stern@rowland.harvard.edu, parri.andrea@gmail.com,
	will.deacon@arm.com, peterz@infradead.org, boqun.feng@gmail.com,
	npiggin@gmail.com, dhowells@redhat.com, j.alglave@ucl.ac.uk,
	luc.maranget@inria.fr, akiyks@gmail.com,
	SeongJae Park <sj38.park@gmail.com>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: [PATCH memory-model 7/8] atomic_ops.rst: Fix wrong example code
Date: Mon, 14 May 2018 15:55:32 -0700	[thread overview]
Message-ID: <1526338533-6044-7-git-send-email-paulmck@linux.vnet.ibm.com> (raw)
In-Reply-To: <20180514225457.GA5142@linux.vnet.ibm.com>

From: SeongJae Park <sj38.park@gmail.com>

Example code snippets for necessary of READ_ONCE() and WRITE_ONCE() has
an unnecessary line of code and wrong condition.  This commit fixes
them.

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
---
 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.
-- 
2.5.2

  parent reply	other threads:[~2018-05-14 22:55 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-14 22:54 [PATCH memory-model 0/8] memory-barriers.txt and atomic_ops.rst updates Paul E. McKenney
2018-05-14 22:55 ` [PATCH memory-model 1/8] docs/memory-barriers.txt: Fix broken DMA vs MMIO ordering example Paul E. McKenney
2018-05-15  6:21   ` [tip:locking/core] locking/memory-barriers.txt: Fix broken DMA vs. " tip-bot for Will Deacon
2018-05-14 22:55 ` [PATCH memory-model 2/8] kokr/doc: READ_ONCE() now implies smp_barrier_depends() Paul E. McKenney
2018-05-15  6:22   ` [tip:locking/core] locking/memory-barriers.txt/kokr: Update Korean translation to indicate that " tip-bot for SeongJae Park
2018-05-14 22:55 ` [PATCH memory-model 3/8] kokr/doc: De-emphasize smp_read_barrier_depends Paul E. McKenney
2018-05-15  6:22   ` [tip:locking/core] locking/memory-barriers.txt/kokr: Update Korean translation to de-emphasize smp_read_barrier_depends() tip-bot for SeongJae Park
2018-05-14 22:55 ` [PATCH memory-model 4/8] kokr/Documentation/memory-barriers.txt: Cross-reference "tools/memory-model/" Paul E. McKenney
2018-05-15  6:23   ` [tip:locking/core] locking/memory-barriers.txt/kokr: Update Korean translation to cross-reference "tools/memory-model/" tip-bot for SeongJae Park
2018-05-14 22:55 ` [PATCH memory-model 5/8] kokr/memory-barriers: Fix description of data dependency barriers Paul E. McKenney
2018-05-15  6:23   ` [tip:locking/core] locking/memory-barriers.txt/kokr: Update Korean translation to fix " tip-bot for SeongJae Park
2018-05-14 22:55 ` [PATCH memory-model 6/8] kokr/locking/memory-barriers: De-emphasize smp_read_barrier_depends() some more Paul E. McKenney
2018-05-15  6:24   ` [tip:locking/core] locking/memory-barriers.txt/kokr: Update Korean translation to de-emphasize " tip-bot for SeongJae Park
2018-05-14 22:55 ` Paul E. McKenney [this message]
2018-05-15  6:24   ` [tip:locking/core] locking/Documentation: Fix incorrect example code tip-bot for SeongJae Park
2018-05-14 22:55 ` [PATCH memory-model 8/8] atomic_ops.rst: Use `warning` rst directive Paul E. McKenney
2018-05-15  6:25   ` [tip:locking/core] locking/Documentation: Use `warning` RST directive tip-bot for SeongJae Park

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