From c7c033d173f2d4f14834c0fb942b84725ac940e8 Mon Sep 17 00:00:00 2001 From: Feifei Wang Date: Thu, 14 Jan 2021 15:08:26 +0800 Subject: [PATCH] app/eventdev: fix SMP barrier in performance test 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: stable@dpdk.org Signed-off-by: Feifei Wang Reviewed-by: Ruifeng Wang Acked-by: Pavan Nikhilesh --- 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 ff9705df88..e7233e5a5b 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; } -- 2.20.1