Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1338779

Re: [PATCH] Documentation/memory-barriers: fix wrong comment in example

Show all headers | View raw

On Sat, Feb 20, 2016 at 03:01:08PM +0900, SeongJae Park wrote:
> There is wrong comment in example for compiler store omit behavior.  It
> shows example of the problem and than problem solved version code.
> However, the comment in the solved version is still same with not solved
> version.  Fix the wrong statement with this commit.
> 
> Signed-off-by: SeongJae Park <sj38.park@gmail.com>

Hmmm...  The code between the two stores of zero to "a" is intended to
remain the same in the broken and fixed versions.  So the only change
is from "a = 0" to "WRITE_ONCE(a, 0)".  Note that it is some other
CPU that did the third store to "a".

Or am I missing your point here?

							Thanx, Paul

> ---
>  Documentation/memory-barriers.txt | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt
> index 061ff29..b4754c7 100644
> --- a/Documentation/memory-barriers.txt
> +++ b/Documentation/memory-barriers.txt
> @@ -1471,7 +1471,7 @@ of optimizations:
>       wrong guess:
> 
>  	WRITE_ONCE(a, 0);
> -	/* Code that does not store to variable a. */
> +	/* Code that does store to variable a. */
>  	WRITE_ONCE(a, 0);
> 
>   (*) The compiler is within its rights to reorder memory accesses unless
> -- 
> 1.9.1
> 

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH] Documentation/memory-barriers: fix wrong comment in example SeongJae Park <sj38.park@gmail.com> - 2016-02-20 07:10 +0100
  Re: [PATCH] Documentation/memory-barriers: fix wrong comment in  example "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-02-20 21:00 +0100
    Re: [PATCH] Documentation/memory-barriers: fix wrong comment in example SeongJae Park <sj38.park@gmail.com> - 2016-02-21 00:00 +0100
      Re: [PATCH] Documentation/memory-barriers: fix wrong comment in example SeongJae Park <sj38.park@gmail.com> - 2016-02-21 19:00 +0100
        Re: [PATCH] Documentation/memory-barriers: fix wrong comment in example David Howells <dhowells@redhat.com> - 2016-02-22 11:10 +0100
          Re: [PATCH] Documentation/memory-barriers: fix wrong comment in  example SeongJae Park <sj38.park@gmail.com> - 2016-02-22 12:10 +0100
            Re: [PATCH] Documentation/memory-barriers: fix wrong comment in example David Howells <dhowells@redhat.com> - 2016-02-22 12:20 +0100
              Re: [PATCH] Documentation/memory-barriers: fix wrong comment in  example "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-02-22 17:40 +0100
                Re: [PATCH] Documentation/memory-barriers: fix wrong comment in example SeongJae Park <sj38.park@gmail.com> - 2016-02-22 22:50 +0100
      Re: [PATCH] Documentation/memory-barriers: fix wrong comment in  example "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-02-22 03:40 +0100

csiph-web