Hi Chung-Lin!

On Sat, 5 Jan 2019 17:47:10 +0800, Chung-Lin Tang <chunglin_tang@mentor.com> wrote:
> this is the current version of the oacc-* parts of the Async Re-work patch.
> 
> I have reverted away from the earlier mentioned attempt of using lockless
> techniques to manage the asyncqueues; it is really hard to do in a 100% correct
> manner, unless we only use something like simple lists to manage them,
> which probably makes lookup unacceptably slow.
> 
> For now, I have changed to use the conventional locking and success/fail return
> codes for the synchronize/serialize hooks.

OK, thanks.


> I hope this is enough to pass
> and get committed.

Well, the "Properly handle wait clause with no arguments" changes still
need to be completed and go in first (to avoid introducing regressions),
and then I will have to see your whole set of changes that you intend to
commit: the bits you've incrementally posted still don't include several
of the changes I suggested and provided patches for (again, to avoid
introducing regressions).


But GCC now is in "regression and documentation fixes mode", so I fear
that it's too late now?


> --- oacc-async.c	(revision 267507)
> +++ oacc-async.c	(working copy)

> @@ -62,12 +158,10 @@ acc_wait (int async)

> +  goacc_aq aq = lookup_goacc_asyncqueue (thr, true, async);
> +  thr->dev->openacc.async.synchronize_func (aq);

Have to check the result here?  Like you're doing here, for example:

>  acc_wait_async (int async1, int async2)
>  {

> +  if (!thr->dev->openacc.async.synchronize_func (aq1))
> +    gomp_fatal ("wait on %d failed", async1);
> +  if (!thr->dev->openacc.async.serialize_func (aq1, aq2))
> +    gomp_fatal ("ordering of async ids %d and %d failed", async1, async2);

> --- oacc-parallel.c	(revision 267507)
> +++ oacc-parallel.c	(working copy)

> @@ -521,17 +500,22 @@ goacc_wait (int async, int num_waits, va_list *ap)

>        if (async == acc_async_sync)
> -	acc_wait (qid);
> +	acc_dev->openacc.async.synchronize_func (aq);

Likewise?

>        else if (qid == async)
> -	;/* If we're waiting on the same asynchronous queue as we're
> -	    launching on, the queue itself will order work as
> -	    required, so there's no need to wait explicitly.  */
> +	/* If we're waiting on the same asynchronous queue as we're
> +	   launching on, the queue itself will order work as
> +	   required, so there's no need to wait explicitly.  */
> +	;
>        else
> -	acc_dev->openacc.async_wait_async_func (qid, async);
> +	{
> +	  goacc_aq aq2 = get_goacc_asyncqueue (async);
> +	  acc_dev->openacc.async.synchronize_func (aq);
> +	  acc_dev->openacc.async.serialize_func (aq, aq2);
> +	}

Likewise?


Also, I had to apply additional changes as attached, to make this build.


Grüße
 Thomas