diff mbox series

[v1,01/12] test/pmd_perf: use compiler atomic builtins for polling sync

Message ID 20210802101847.3462-2-joyce.kong@arm.com (mailing list archive)
State Superseded, archived
Delegated to: Thomas Monjalon
Headers
Series use compiler atomic builtins for app |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Joyce Kong Aug. 2, 2021, 10:18 a.m. UTC 
  Convert rte_atomic usages to compiler atomic built-ins
for polling sync in pmd_perf test cases.

Signed-off-by: Joyce Kong <joyce.kong@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
---
 app/test/test_pmd_perf.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

Comments

Honnappa Nagarahalli Nov. 8, 2021, 10:50 p.m. UTC | #1 
<snip>

> 
> Convert rte_atomic usages to compiler atomic built-ins for polling sync in
> pmd_perf test cases.
> 
> Signed-off-by: Joyce Kong <joyce.kong@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang@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.

> 
>  	/* wait for polling finished */
>  	diff_tsc = rte_eal_wait_lcore(lcore);
> --
> 2.17.1
Joyce Kong Nov. 10, 2021, 6:10 a.m. UTC | #2 
> <snip>
> 
> >
> > Convert rte_atomic usages to compiler atomic built-ins for polling
> > sync in pmd_perf test cases.
> >
> > Signed-off-by: Joyce Kong <joyce.kong@arm.com>
> > Reviewed-by: Ruifeng Wang <ruifeng.wang@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
diff mbox series

Patch

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);
 
 	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);
 
 	/* 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);
 
 	/* wait for polling finished */
 	diff_tsc = rte_eal_wait_lcore(lcore);