Re: [dpdk-dev] [PATCH v1 04/12] test/stack_perf: use compiler atomics for lcore sync

[Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>]

<snip>

> 
> Convert rte_atomic usages to compiler atomic built-ins for lcore sync in
> stack_perf test cases.
> 
> Signed-off-by: Joyce Kong <joyce.kong@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Looks good
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>

> ---
>  app/test/test_stack_perf.c | 14 ++++++--------
>  1 file changed, 6 insertions(+), 8 deletions(-)
> 
> diff --git a/app/test/test_stack_perf.c b/app/test/test_stack_perf.c index
> 4ee40d5d19..1eae00a334 100644
> --- a/app/test/test_stack_perf.c
> +++ b/app/test/test_stack_perf.c
> @@ -6,7 +6,6 @@
>  #include <stdio.h>
>  #include <inttypes.h>
> 
> -#include <rte_atomic.h>
>  #include <rte_cycles.h>
>  #include <rte_launch.h>
>  #include <rte_pause.h>
> @@ -24,7 +23,7 @@
>   */
>  static volatile unsigned int bulk_sizes[] = {8, MAX_BURST};
> 
> -static rte_atomic32_t lcore_barrier;
> +static uint32_t lcore_barrier;
> 
>  struct lcore_pair {
>  	unsigned int c1;
> @@ -144,9 +143,8 @@ bulk_push_pop(void *p)
>  	s = args->s;
>  	size = args->sz;
> 
> -	rte_atomic32_sub(&lcore_barrier, 1);
> -	while (rte_atomic32_read(&lcore_barrier) != 0)
> -		rte_pause();
> +	__atomic_fetch_sub(&lcore_barrier, 1, __ATOMIC_RELAXED);
> +	rte_wait_until_equal_32(&lcore_barrier, 0, __ATOMIC_RELAXED);
> 
>  	uint64_t start = rte_rdtsc();
> 
> @@ -175,7 +173,7 @@ run_on_core_pair(struct lcore_pair *cores, struct
> rte_stack *s,
>  	unsigned int i;
> 
>  	for (i = 0; i < RTE_DIM(bulk_sizes); i++) {
> -		rte_atomic32_set(&lcore_barrier, 2);
> +		__atomic_store_n(&lcore_barrier, 2, __ATOMIC_RELAXED);
> 
>  		args[0].sz = args[1].sz = bulk_sizes[i];
>  		args[0].s = args[1].s = s;
> @@ -208,7 +206,7 @@ run_on_n_cores(struct rte_stack *s, lcore_function_t
> fn, int n)
>  		int cnt = 0;
>  		double avg;
> 
> -		rte_atomic32_set(&lcore_barrier, n);
> +		__atomic_store_n(&lcore_barrier, n, __ATOMIC_RELAXED);
> 
>  		RTE_LCORE_FOREACH_WORKER(lcore_id) {
>  			if (++cnt >= n)
> @@ -302,7 +300,7 @@ __test_stack_perf(uint32_t flags)
>  	struct lcore_pair cores;
>  	struct rte_stack *s;
> 
> -	rte_atomic32_init(&lcore_barrier);
> +	__atomic_store_n(&lcore_barrier, 0, __ATOMIC_RELAXED);
> 
>  	s = rte_stack_create(STACK_NAME, STACK_SIZE, rte_socket_id(),
> flags);
>  	if (s == NULL) {
> --
> 2.17.1