RE: [PATCH v1 07/12] app/eventdev: use compiler atomic builtins for packets sync

[Joyce Kong <Joyce.Kong@arm.com>]

> <snip>
> 
> > Subject: [PATCH v1 07/12] app/eventdev: use compiler atomic builtins
> > for packets sync
> How about the following:
> app/eventdev: use compiler atomic builtins for shared data synchronization
> 

Yes, please see next version.

> >
> > Convert rte_atomic usages to compiler atomic built-ins for
> > outstanding_pkts sync in eventdev cases.
> >
> 
> <snip>
> 
> > diff --git a/app/test-eventdev/test_order_common.h b/app/test-
> > eventdev/test_order_common.h index cd9d6009ec..1507265928 100644
> > --- a/app/test-eventdev/test_order_common.h
> > +++ b/app/test-eventdev/test_order_common.h
> > @@ -48,7 +48,7 @@ struct test_order {
> >  	 * The atomic_* is an expensive operation,Since it is a functional test,
> >  	 * We are using the atomic_ operation to reduce the code complexity.
> >  	 */
> > -	rte_atomic64_t outstand_pkts;
> > +	uint64_t outstand_pkts;
> >  	enum evt_test_result result;
> >  	uint32_t nb_flows;
> >  	uint64_t nb_pkts;
> > @@ -95,7 +95,7 @@ static __rte_always_inline void
> > order_process_stage_1(struct test_order *const t,
> >  		struct rte_event *const ev, const uint32_t nb_flows,
> >  		uint32_t *const expected_flow_seq,
> > -		rte_atomic64_t *const outstand_pkts)
> > +		uint64_t *const outstand_pkts)
> >  {
> >  	const uint32_t flow = (uintptr_t)ev->mbuf % nb_flows;
> >  	/* compare the seqn against expected value */ @@ -113,7 +113,7
> @@
> > order_process_stage_1(struct test_order *const t,
> >  	 */
> >  	expected_flow_seq[flow]++;
> >  	rte_pktmbuf_free(ev->mbuf);
> > -	rte_atomic64_sub(outstand_pkts, 1);
> > +	__atomic_fetch_sub(outstand_pkts, 1, __ATOMIC_RELAXED);
> >  }
> >
> >  static __rte_always_inline void
> > @@ -132,7 +132,7 @@ order_process_stage_invalid(struct test_order
> > *const t,
> >  	const uint8_t port = w->port_id;\
> >  	const uint32_t nb_flows = t->nb_flows;\
> >  	uint32_t *expected_flow_seq = t->expected_flow_seq;\
> > -	rte_atomic64_t *outstand_pkts = &t->outstand_pkts;\
> > +	uint64_t *outstand_pkts = &t->outstand_pkts;\
> We could use the atomic built-in to set this? We have been doing that in
> other places.

Here is an address operation, so atomic built-in may not be used. 

> 
> >  	if (opt->verbose_level > 1)\
> >  		printf("%s(): lcore %d dev_id %d port=%d\n",\
> >  			__func__, rte_lcore_id(), dev_id, port) diff --git
> 
> <snip>