+ Ferruh
<snip>
Hi Joyce/Ferruh,
I do not think the port_status changes need to be handled atomically. The
changes to port_status do not seem to be happening from multiple threads. It
seems to be getting modified during initialization or through the test pmd
prompt.
Do we really need atomic operations on port_status?
>
> Replace rte_atomic16_cmpset operation with compiler atomic CAS operation
> for port status sync in testpmd case.
>
> Signed-off-by: Joyce Kong <joyce.k...@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.w...@arm.com>
> ---
> app/test-pmd/testpmd.c | 75 +++++++++++++++++++++++++++---------------
> 1 file changed, 48 insertions(+), 27 deletions(-)
>
> diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c index
> 6cbe9ba3c8..22579dd438 100644
> --- a/app/test-pmd/testpmd.c
> +++ b/app/test-pmd/testpmd.c
> @@ -36,7 +36,6 @@
> #include <rte_alarm.h>
> #include <rte_per_lcore.h>
> #include <rte_lcore.h>
> -#include <rte_atomic.h>
> #include <rte_branch_prediction.h>
> #include <rte_mempool.h>
> #include <rte_malloc.h>
> @@ -2302,6 +2301,7 @@ setup_hairpin_queues(portid_t pi, portid_t p_pi,
> uint16_t cnt_pi)
> uint16_t peer_tx_port = pi;
> uint32_t manual = 1;
> uint32_t tx_exp = hairpin_mode & 0x10;
> + uint16_t port_exp;
>
> if (!(hairpin_mode & 0xf)) {
> peer_rx_port = pi;
> @@ -2347,10 +2347,11 @@ setup_hairpin_queues(portid_t pi, portid_t p_pi,
> uint16_t cnt_pi)
> if (diag == 0)
> continue;
>
> + port_exp = RTE_PORT_HANDLING;
> /* Fail to setup rx queue, return */
> - if (rte_atomic16_cmpset(&(port->port_status),
> - RTE_PORT_HANDLING,
> - RTE_PORT_STOPPED) == 0)
> + if (__atomic_compare_exchange_n(&(port->port_status),
> + &port_exp, RTE_PORT_STOPPED, 0,
> + __ATOMIC_RELAXED, __ATOMIC_RELAXED)
> == 0)
> fprintf(stderr,
> "Port %d can not be set back to stopped\n",
> pi);
> fprintf(stderr, "Fail to configure port %d hairpin queues\n",
> @@ -2370,10 +2371,11 @@ setup_hairpin_queues(portid_t pi, portid_t p_pi,
> uint16_t cnt_pi)
> if (diag == 0)
> continue;
>
> + port_exp = RTE_PORT_HANDLING;
> /* Fail to setup rx queue, return */
> - if (rte_atomic16_cmpset(&(port->port_status),
> - RTE_PORT_HANDLING,
> - RTE_PORT_STOPPED) == 0)
> + if (__atomic_compare_exchange_n(&(port->port_status),
> + &port_exp, RTE_PORT_STOPPED, 0,
> + __ATOMIC_RELAXED, __ATOMIC_RELAXED)
> == 0)
> fprintf(stderr,
> "Port %d can not be set back to stopped\n",
> pi);
> fprintf(stderr, "Fail to configure port %d hairpin queues\n",
> @@ -2444,6 +2446,7 @@ start_port(portid_t pid)
> queueid_t qi;
> struct rte_port *port;
> struct rte_eth_hairpin_cap cap;
> + uint16_t port_exp;
>
> if (port_id_is_invalid(pid, ENABLED_WARN))
> return 0;
> @@ -2454,8 +2457,10 @@ start_port(portid_t pid)
>
> need_check_link_status = 0;
> port = &ports[pi];
> - if (rte_atomic16_cmpset(&(port->port_status),
> RTE_PORT_STOPPED,
> - RTE_PORT_HANDLING) == 0)
> {
> + port_exp = RTE_PORT_STOPPED;
> + if (__atomic_compare_exchange_n(&(port->port_status),
> + &port_exp, RTE_PORT_HANDLING, 0,
> + __ATOMIC_RELAXED, __ATOMIC_RELAXED)
> == 0) {
> fprintf(stderr, "Port %d is now not stopped\n", pi);
> continue;
> }
> @@ -2487,8 +2492,10 @@ start_port(portid_t pid)
> nb_txq + nb_hairpinq,
> &(port->dev_conf));
> if (diag != 0) {
> - if (rte_atomic16_cmpset(&(port-
> >port_status),
> - RTE_PORT_HANDLING, RTE_PORT_STOPPED)
> == 0)
> + port_exp = RTE_PORT_HANDLING;
> + if (__atomic_compare_exchange_n(&(port-
> >port_status),
> + &port_exp,
> RTE_PORT_STOPPED, 0,
> + __ATOMIC_RELAXED,
> __ATOMIC_RELAXED) == 0)
> fprintf(stderr,
> "Port %d can not be set back
> to stopped\n",
> pi);
> @@ -2518,10 +2525,11 @@ start_port(portid_t pid)
> if (diag == 0)
> continue;
>
> + port_exp = RTE_PORT_HANDLING;
> /* Fail to setup tx queue, return */
> - if (rte_atomic16_cmpset(&(port-
> >port_status),
> -
> RTE_PORT_HANDLING,
> - RTE_PORT_STOPPED)
> == 0)
> + if (__atomic_compare_exchange_n(&(port-
> >port_status),
> + &port_exp,
> RTE_PORT_STOPPED, 0,
> + __ATOMIC_RELAXED,
> __ATOMIC_RELAXED) == 0)
> fprintf(stderr,
> "Port %d can not be set back
> to stopped\n",
> pi);
> @@ -2570,10 +2578,11 @@ start_port(portid_t pid)
> if (diag == 0)
> continue;
>
> + port_exp = RTE_PORT_HANDLING;
> /* Fail to setup rx queue, return */
> - if (rte_atomic16_cmpset(&(port-
> >port_status),
> -
> RTE_PORT_HANDLING,
> - RTE_PORT_STOPPED)
> == 0)
> + if (__atomic_compare_exchange_n(&(port-
> >port_status),
> + &port_exp,
> RTE_PORT_STOPPED, 0,
> + __ATOMIC_RELAXED,
> __ATOMIC_RELAXED) == 0)
> fprintf(stderr,
> "Port %d can not be set back
> to stopped\n",
> pi);
> @@ -2607,17 +2616,21 @@ start_port(portid_t pid)
> fprintf(stderr, "Fail to start port %d: %s\n",
> pi, rte_strerror(-diag));
>
> + port_exp = RTE_PORT_HANDLING;
> /* Fail to setup rx queue, return */
> - if (rte_atomic16_cmpset(&(port->port_status),
> - RTE_PORT_HANDLING, RTE_PORT_STOPPED)
> == 0)
> + if (__atomic_compare_exchange_n(&(port-
> >port_status),
> + &port_exp, RTE_PORT_STOPPED, 0,
> + __ATOMIC_RELAXED,
> __ATOMIC_RELAXED) == 0)
> fprintf(stderr,
> "Port %d can not be set back to
> stopped\n",
> pi);
> continue;
> }
>
> - if (rte_atomic16_cmpset(&(port->port_status),
> - RTE_PORT_HANDLING, RTE_PORT_STARTED) == 0)
> + port_exp = RTE_PORT_HANDLING;
> + if (__atomic_compare_exchange_n(&(port->port_status),
> + &port_exp, RTE_PORT_STARTED, 0,
> + __ATOMIC_RELAXED, __ATOMIC_RELAXED)
> == 0)
> fprintf(stderr, "Port %d can not be set into started\n",
> pi);
>
> @@ -2697,6 +2710,7 @@ stop_port(portid_t pid)
> int need_check_link_status = 0;
> portid_t peer_pl[RTE_MAX_ETHPORTS];
> int peer_pi;
> + uint16_t port_exp;
>
> if (port_id_is_invalid(pid, ENABLED_WARN))
> return;
> @@ -2722,8 +2736,10 @@ stop_port(portid_t pid)
> }
>
> port = &ports[pi];
> - if (rte_atomic16_cmpset(&(port->port_status),
> RTE_PORT_STARTED,
> - RTE_PORT_HANDLING) == 0)
> + port_exp = RTE_PORT_STARTED;
> + if (__atomic_compare_exchange_n(&(port->port_status),
> + &port_exp, RTE_PORT_HANDLING, 0,
> + __ATOMIC_RELAXED, __ATOMIC_RELAXED)
> == 0)
> continue;
>
> if (hairpin_mode & 0xf) {
> @@ -2749,8 +2765,10 @@ stop_port(portid_t pid)
> RTE_LOG(ERR, EAL, "rte_eth_dev_stop failed for port
> %u\n",
> pi);
>
> - if (rte_atomic16_cmpset(&(port->port_status),
> - RTE_PORT_HANDLING, RTE_PORT_STOPPED) == 0)
> + port_exp = RTE_PORT_HANDLING;
> + if (__atomic_compare_exchange_n(&(port->port_status),
> + &port_exp, RTE_PORT_STOPPED, 0,
> + __ATOMIC_RELAXED, __ATOMIC_RELAXED)
> == 0)
> fprintf(stderr, "Port %d can not be set into
> stopped\n",
> pi);
> need_check_link_status = 1;
> @@ -2788,6 +2806,7 @@ close_port(portid_t pid) {
> portid_t pi;
> struct rte_port *port;
> + uint16_t port_exp;
>
> if (port_id_is_invalid(pid, ENABLED_WARN))
> return;
> @@ -2813,8 +2832,10 @@ close_port(portid_t pid)
> }
>
> port = &ports[pi];
> - if (rte_atomic16_cmpset(&(port->port_status),
> - RTE_PORT_CLOSED, RTE_PORT_CLOSED) == 1) {
> + port_exp = RTE_PORT_CLOSED;
> + if (__atomic_compare_exchange_n(&(port->port_status),
> + &port_exp, RTE_PORT_CLOSED, 0,
> + __ATOMIC_RELAXED, __ATOMIC_RELAXED)) {
> fprintf(stderr, "Port %d is already closed\n", pi);
> continue;
> }
> --
> 2.17.1
