> <snip>
>
> >
> > Convert rte_atomic usages to compiler atomic built-ins for polling
> > sync in pmd_perf test cases.
> >
> > Signed-off-by: Joyce Kong <joyce.k...@arm.com>
> > Reviewed-by: Ruifeng Wang <ruifeng.w...@arm.com>
> > ---
> > app/test/test_pmd_perf.c | 12 +++++-------
> > 1 file changed, 5 insertions(+), 7 deletions(-)
> >
> > diff --git a/app/test/test_pmd_perf.c b/app/test/test_pmd_perf.c index
> > 3a248d512c..41ef001b90 100644
> > --- a/app/test/test_pmd_perf.c
> > +++ b/app/test/test_pmd_perf.c
> > @@ -10,7 +10,6 @@
> > #include <rte_cycles.h>
> > #include <rte_ethdev.h>
> > #include <rte_byteorder.h>
> > -#include <rte_atomic.h>
> > #include <rte_malloc.h>
> > #include "packet_burst_generator.h"
> > #include "test.h"
> > @@ -526,7 +525,7 @@ main_loop(__rte_unused void *args)
> > return 0;
> > }
> >
> > -static rte_atomic64_t start;
> > +static uint64_t start;
> >
> > static inline int
> > poll_burst(void *args)
> > @@ -564,8 +563,7 @@ poll_burst(void *args)
> > num[portid] = pkt_per_port;
> > }
> >
> > - while (!rte_atomic64_read(&start))
> > - ;
> > + rte_wait_until_equal_64(&start, 1, __ATOMIC_RELAXED);
> This needs to be ACQUIRE. Please see comments below for function
> 'exec_burst'.
>
> >
> > cur_tsc = rte_rdtsc();
> > while (total) {
> > @@ -617,7 +615,7 @@ exec_burst(uint32_t flags, int lcore)
> > pkt_per_port = MAX_TRAFFIC_BURST;
> > num = pkt_per_port * conf->nb_ports;
> >
> > - rte_atomic64_init(&start);
> > + __atomic_store_n(&start, 0, __ATOMIC_RELAXED);
> >
> > /* start polling thread, but not actually poll yet */
> > rte_eal_remote_launch(poll_burst,
> > @@ -625,7 +623,7 @@ exec_burst(uint32_t flags, int lcore)
> >
> > /* Only when polling first */
> > if (flags == SC_BURST_POLL_FIRST)
> > - rte_atomic64_set(&start, 1);
> > + __atomic_store_n(&start, 1, __ATOMIC_RELAXED);
> This line can be combined with initialization of 'start'. i.e.
> if (flags == SC_BURST_POLL_FIRST) {
> __atomic_store_n(&start, 1, __ATOMIC_RELAXED); } else {
> __atomic_store_n(&start, 0, __ATOMIC_RELAXED); } It is ok to use
> RELAXED here as it is part of initialization and 'rte_eal_remote_launch' will
> ensure that the store to 'start' is visible to the worker thread.
>
> >
> > /* start xmit */
> > i = 0;
> > @@ -642,7 +640,7 @@ exec_burst(uint32_t flags, int lcore)
> >
> > /* only when polling second */
> > if (flags == SC_BURST_XMIT_FIRST)
> > - rte_atomic64_set(&start, 1);
> > + __atomic_store_n(&start, 1, __ATOMIC_RELAXED);
> This store should happen after transmitting the packets. It is better to use
> RELEASE here.
Thanks, Honnappa, will make the changes in next version.
Joyce
>
> >
> > /* wait for polling finished */
> > diff_tsc = rte_eal_wait_lcore(lcore);
> > --
> > 2.17.1
