Re: [V9fs-developer] [PATCH v2 1/6] 9p: Fix comment on smp_wmb

From: Greg Kurz
Date: Thu Jul 12 2018 - 08:31:19 EST


On Wed, 11 Jul 2018 14:02:20 -0700
Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote:

> The previous comment misled me into thinking the barrier wasn't needed
> at all.
>
> Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
> ---

Reviewed-by: Greg Kurz <groug@xxxxxxxx>

> net/9p/client.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/9p/client.c b/net/9p/client.c
> index 18c5271910dc..999eceb8af98 100644
> --- a/net/9p/client.c
> +++ b/net/9p/client.c
> @@ -447,7 +447,7 @@ void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
>
> /*
> * This barrier is needed to make sure any change made to req before
> - * the other thread wakes up will indeed be seen by the waiting side.
> + * the status change is visible to another thread
> */
> smp_wmb();
> req->status = status;