[dpdk-stable] patch 'test/trace: fix race on collected perf data' has been queued to stable release 20.11.2

[Xueming Li]

Hi,

FYI, your patch has been queued to stable release 20.11.2

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 05/12/21. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/steevenlee/dpdk

This queued commit can be viewed at:
https://github.com/steevenlee/dpdk/commit/d2d434683d83eb9efc4b627e0ac55fc436d626b3

Thanks.

Xueming Li <xuemingl at nvidia.com>

---
>From d2d434683d83eb9efc4b627e0ac55fc436d626b3 Mon Sep 17 00:00:00 2001
From: Feifei Wang <feifei.wang2 at arm.com>
Date: Wed, 10 Mar 2021 10:15:27 +0800
Subject: [PATCH] test/trace: fix race on collected perf data
Cc: Luca Boccassi <bluca at debian.org>

[ upstream commit dda66e716c0550ee8b218428a6d2129bd9c97740 ]

The measure_perf function should be executed after worker threads exit
to collect correct perf data. Otherwise, while workers are running, the
main thread may get incomplete data from workers.

In the meanwhile, remove unnecessary barrier in the test.
For signal variables "ldata.done" and "ldata.start", no operations
should keep the order that being executed after them. So the wmb after
them can be moved.

Fixes: 16a277a24c9f ("test/trace: add performance test cases")

Suggested-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
Signed-off-by: Feifei Wang <feifei.wang2 at arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang at arm.com>
Acked-by: Pavan Nikhilesh <pbhagavatula at marvell.com>
Acked-by: Jerin Jacob <jerinj at marvell.com>
---
 app/test/test_trace_perf.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/app/test/test_trace_perf.c b/app/test/test_trace_perf.c
index e1ad8e6f55..46ae7d8074 100644
--- a/app/test/test_trace_perf.c
+++ b/app/test/test_trace_perf.c
@@ -79,7 +79,6 @@ signal_workers_to_finish(struct test_data *data)
 
 	for (workers = 0; workers < data->nb_workers; workers++) {
 		data->ldata[workers].done = 1;
-		rte_smp_wmb();
 	}
 }
 
@@ -102,7 +101,6 @@ worker_fn_##func(void *arg) \
 { \
 	struct lcore_data *ldata = arg; \
 	ldata->started = 1; \
-	rte_smp_wmb(); \
 	__worker_##func(ldata); \
 	return 0; \
 }
@@ -137,11 +135,12 @@ run_test(const char *str, lcore_function_t f, struct test_data *data, size_t sz)
 
 	wait_till_workers_are_ready(data);
 	rte_delay_ms(100); /* Wait for some time to accumulate the stats */
-	measure_perf(str, data);
 	signal_workers_to_finish(data);
 
 	RTE_LCORE_FOREACH_WORKER(id)
 		rte_eal_wait_lcore(id);
+
+	measure_perf(str, data);
 }
 
 static int
-- 
2.25.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2021-05-10 23:59:30.976499800 +0800
+++ 0170-test-trace-fix-race-on-collected-perf-data.patch	2021-05-10 23:59:26.610000000 +0800
@@ -1 +1 @@
-From dda66e716c0550ee8b218428a6d2129bd9c97740 Mon Sep 17 00:00:00 2001
+From d2d434683d83eb9efc4b627e0ac55fc436d626b3 Mon Sep 17 00:00:00 2001
@@ -4,0 +5,3 @@
+Cc: Luca Boccassi <bluca at debian.org>
+
+[ upstream commit dda66e716c0550ee8b218428a6d2129bd9c97740 ]
@@ -16 +18,0 @@
-Cc: stable at dpdk.org