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SubjectRe: [PATCH v3 2/5] Documentation/locking/atomic: Fix atomic-set litmus test
On Thu, 27 Feb 2020, Boqun Feng wrote:

> Currently the litmus test "atomic-set" in atomic_t.txt has a few things
> to be improved:
>
> 1) The CPU/Processor numbers "P1,P2" are not only inconsistent with
> the rest of the document, which uses "CPU0" and "CPU1", but also
> unacceptable by the herd tool, which requires processors start
> at "P0".
>
> 2) The initialization block uses a "atomic_set()", which is OK, but
> it's better to use ATOMIC_INIT() to make clear this is an
> initialization.
>
> 3) The return value of atomic_add_unless() is discarded
> inexplicitly, which is OK for C language, but it will be helpful
> to the herd tool if we use a void cast to make the discard
> explicit.
>
> Therefore fix these and this is the preparation for adding the litmus
> test into memory-model litmus-tests directory so that people can
> understand better about our requirements of atomic APIs and klitmus tool
> can be used to generate tests.
>
> Signed-off-by: Boqun Feng <boqun.feng@gmail.com>

Patch 5/5 in this series does basically the same thing for
Atomic-RMW+mb__after_atomic-is-stronger-than-acquire. How come you
used one patch for that, but this is split into two patches (2/5 and
4/5)?

Alan

> ---
> Documentation/atomic_t.txt | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/atomic_t.txt b/Documentation/atomic_t.txt
> index 0ab747e0d5ac..ceb85ada378e 100644
> --- a/Documentation/atomic_t.txt
> +++ b/Documentation/atomic_t.txt
> @@ -91,15 +91,15 @@ ops. That is:
> C atomic-set
>
> {
> - atomic_set(v, 1);
> + atomic_t v = ATOMIC_INIT(1);
> }
>
> - P1(atomic_t *v)
> + P0(atomic_t *v)
> {
> - atomic_add_unless(v, 1, 0);
> + (void)atomic_add_unless(v, 1, 0);
> }
>
> - P2(atomic_t *v)
> + P1(atomic_t *v)
> {
> atomic_set(v, 0);
> }
>


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