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@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: akiyks@gmail.com
Cc: boqun.feng@gmail.com
Cc: dhowells@redhat.com
Cc: j.alglave@ucl.ac.uk
Cc: linux-arch@vger.kernel.org
Cc: luc.maranget@inria.fr
Cc: npiggin@gmail.com
Cc: parri.andrea@gmail.com
Link: http://lkml.kernel.org/r/1526338533-6044-7-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
SeongJae Park 2018-05-14 15:55:32 -07:00 committed by Ingo Molnar
parent e89641dd03
commit fc7bdc9024

View File

@ -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.