From: Feifei Wang <feifei.wang2@arm.com>
To: Jerin Jacob <jerinj@marvell.com>,
Harry van Haaren <harry.van.haaren@intel.com>
Cc: dev@dpdk.org, nd@arm.com, Honnappa.Nagarahalli@arm.com,
Feifei Wang <feifei.wang2@arm.com>,
stable@dpdk.org
Subject: [dpdk-stable] [RFC PATCH v1 1/6] app/eventdev: fix SMP barrier bugs for perf test
Date: Tue, 22 Dec 2020 13:07:22 +0800 [thread overview]
Message-ID: <20201222050728.41000-2-feifei.wang2@arm.com> (raw)
In-Reply-To: <20201222050728.41000-1-feifei.wang2@arm.com>
This patch fixes RTE SMP barrier bugs for the perf test of eventdev.
For the "perf_process_last_stage" function, wmb after storing
processed_pkts should be moved before it. This is because the worker
lcore should ensure it has really finished data processing, e.g. event
stored into buffers, before the shared variables "w->processed_pkts"are
stored.
For the "perf_process_last_stage_latency", on the one hand, the wmb
should be moved before storing into "w->processed_pkts". The reason is
the same as above. But on the other hand, for "w->latency", wmb is
unnecessary due to data dependency.
Fixes: 2369f73329f8 ("app/testeventdev: add perf queue worker functions")
Cc: jerinj@marvell.com
Cc: stable@dpdk.org
Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
---
app/test-eventdev/test_perf_common.h | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/app/test-eventdev/test_perf_common.h b/app/test-eventdev/test_perf_common.h
index ff9705df8..e7233e5a5 100644
--- a/app/test-eventdev/test_perf_common.h
+++ b/app/test-eventdev/test_perf_common.h
@@ -97,8 +97,13 @@ perf_process_last_stage(struct rte_mempool *const pool,
void *bufs[], int const buf_sz, uint8_t count)
{
bufs[count++] = ev->event_ptr;
- w->processed_pkts++;
+
+ /* wmb here ensures event_prt is stored before
+ * updating the number of processed packets
+ * for worker lcores
+ */
rte_smp_wmb();
+ w->processed_pkts++;
if (unlikely(count == buf_sz)) {
count = 0;
@@ -116,6 +121,12 @@ perf_process_last_stage_latency(struct rte_mempool *const pool,
struct perf_elt *const m = ev->event_ptr;
bufs[count++] = ev->event_ptr;
+
+ /* wmb here ensures event_prt is stored before
+ * updating the number of processed packets
+ * for worker lcores
+ */
+ rte_smp_wmb();
w->processed_pkts++;
if (unlikely(count == buf_sz)) {
@@ -127,7 +138,6 @@ perf_process_last_stage_latency(struct rte_mempool *const pool,
}
w->latency += latency;
- rte_smp_wmb();
return count;
}
--
2.17.1
next parent reply other threads:[~2020-12-22 5:07 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20201222050728.41000-1-feifei.wang2@arm.com>
2020-12-22 5:07 ` Feifei Wang [this message]
2020-12-22 5:07 ` [dpdk-stable] [RFC PATCH v1 4/6] app/eventdev: add release barriers for pipeline test Feifei Wang
[not found] <20201222032237.36046-1-feifei.wang2@arm.com>
2020-12-22 3:22 ` [dpdk-stable] [RFC PATCH v1 1/6] app/eventdev: fix SMP barrier bugs for perf test Feifei Wang
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