From: Stephen Hemminger <stephen@networkplumber.org>
To: roretzla@linux.microsoft.com
Cc: dev@dpdk.org, "Stephen Hemminger" <stephen@networkplumber.org>,
"Morten Brørup" <mb@smartsharesystems.com>
Subject: [PATCH 2/2] latencystats: replace use of VLA
Date: Mon, 6 May 2024 19:53:55 -0700 [thread overview]
Message-ID: <20240507025355.7145-2-stephen@networkplumber.org> (raw)
In-Reply-To: <20240507025355.7145-1-stephen@networkplumber.org>
The temporary array latencystats is not needed if the algorithm
is converted into one pass.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Morten Brørup <mb@smartsharesystems.com>
Acked-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
---
lib/latencystats/rte_latencystats.c | 31 +++++++++++++++--------------
1 file changed, 16 insertions(+), 15 deletions(-)
diff --git a/lib/latencystats/rte_latencystats.c b/lib/latencystats/rte_latencystats.c
index 4ea9b0d75b..9b345bfb33 100644
--- a/lib/latencystats/rte_latencystats.c
+++ b/lib/latencystats/rte_latencystats.c
@@ -157,9 +157,9 @@ calc_latency(uint16_t pid __rte_unused,
uint16_t nb_pkts,
void *_ __rte_unused)
{
- unsigned int i, cnt = 0;
+ unsigned int i;
uint64_t now;
- float latency[nb_pkts];
+ float latency;
static float prev_latency;
/*
* Alpha represents degree of weighting decrease in EWMA,
@@ -169,13 +169,14 @@ calc_latency(uint16_t pid __rte_unused,
const float alpha = 0.2;
now = rte_rdtsc();
- for (i = 0; i < nb_pkts; i++) {
- if (pkts[i]->ol_flags & timestamp_dynflag)
- latency[cnt++] = now - *timestamp_dynfield(pkts[i]);
- }
rte_spinlock_lock(&glob_stats->lock);
- for (i = 0; i < cnt; i++) {
+ for (i = 0; i < nb_pkts; i++) {
+ if (!(pkts[i]->ol_flags & timestamp_dynflag))
+ continue;
+
+ latency = now - *timestamp_dynfield(pkts[i]);
+
/*
* The jitter is calculated as statistical mean of interpacket
* delay variation. The "jitter estimate" is computed by taking
@@ -187,22 +188,22 @@ calc_latency(uint16_t pid __rte_unused,
* Reference: Calculated as per RFC 5481, sec 4.1,
* RFC 3393 sec 4.5, RFC 1889 sec.
*/
- glob_stats->jitter += (fabsf(prev_latency - latency[i])
+ glob_stats->jitter += (fabsf(prev_latency - latency)
- glob_stats->jitter)/16;
if (glob_stats->min_latency == 0)
- glob_stats->min_latency = latency[i];
- else if (latency[i] < glob_stats->min_latency)
- glob_stats->min_latency = latency[i];
- else if (latency[i] > glob_stats->max_latency)
- glob_stats->max_latency = latency[i];
+ glob_stats->min_latency = latency;
+ else if (latency < glob_stats->min_latency)
+ glob_stats->min_latency = latency;
+ else if (latency > glob_stats->max_latency)
+ glob_stats->max_latency = latency;
/*
* The average latency is measured using exponential moving
* average, i.e. using EWMA
* https://en.wikipedia.org/wiki/Moving_average
*/
glob_stats->avg_latency +=
- alpha * (latency[i] - glob_stats->avg_latency);
- prev_latency = latency[i];
+ alpha * (latency - glob_stats->avg_latency);
+ prev_latency = latency;
}
rte_spinlock_unlock(&glob_stats->lock);
--
2.43.0
next prev parent reply other threads:[~2024-05-07 2:54 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-17 23:41 [PATCH 00/16] remove use of VLAs for Windows built code Tyler Retzlaff
2024-04-17 23:41 ` [PATCH 01/16] eal: include header required for alloca Tyler Retzlaff
2024-04-17 23:41 ` [PATCH 02/16] hash: remove use of VLAs for Windows built code Tyler Retzlaff
2024-04-18 6:45 ` Morten Brørup
2024-04-17 23:41 ` [PATCH 03/16] ethdev: " Tyler Retzlaff
2024-04-17 23:41 ` [PATCH 04/16] gro: " Tyler Retzlaff
2024-04-17 23:41 ` [PATCH 05/16] latencystats: " Tyler Retzlaff
2024-04-17 23:41 ` [PATCH 06/16] lpm: " Tyler Retzlaff
2024-04-17 23:41 ` [PATCH 07/16] rcu: " Tyler Retzlaff
2024-04-17 23:41 ` [PATCH 08/16] app/testpmd: " Tyler Retzlaff
2024-04-17 23:41 ` [PATCH 09/16] test: " Tyler Retzlaff
2024-04-17 23:41 ` [PATCH 10/16] common/idpf: " Tyler Retzlaff
2024-04-17 23:41 ` [PATCH 11/16] net/i40e: " Tyler Retzlaff
2024-04-17 23:41 ` [PATCH 12/16] net/ice: " Tyler Retzlaff
2024-04-17 23:41 ` [PATCH 13/16] net/ixgbe: " Tyler Retzlaff
2024-04-17 23:41 ` [PATCH 14/16] common/mlx5: " Tyler Retzlaff
2024-04-17 23:41 ` [PATCH 15/16] net/mlx5: " Tyler Retzlaff
2024-04-17 23:41 ` [PATCH 16/16] build: enable vla warnings on " Tyler Retzlaff
2024-04-18 6:48 ` Morten Brørup
2024-04-18 15:12 ` Tyler Retzlaff
2024-04-18 15:23 ` Bruce Richardson
2024-04-18 19:22 ` Morten Brørup
2024-04-18 6:49 ` [PATCH 00/16] remove use of VLAs for " Morten Brørup
2024-04-18 12:11 ` Konstantin Ananyev
2024-04-18 15:15 ` Tyler Retzlaff
2024-04-18 15:35 ` Konstantin Ananyev
2024-04-18 20:02 ` [PATCH v2 00/19] remove use of VLAs for Windows Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 01/19] eal: include header required for alloca Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 02/19] eal/linux: remove use of VLAs Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 03/19] eal/common: " Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 04/19] ethdev: remove use of VLAs for Windows built code Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 05/19] hash: " Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 06/19] hash/thash: " Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 07/19] rcu: " Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 08/19] gro: " Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 09/19] latencystats: " Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 10/19] lpm: " Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 11/19] app/testpmd: " Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 12/19] test: " Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 13/19] common/idpf: " Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 14/19] net/i40e: " Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 15/19] net/ice: " Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 16/19] net/ixgbe: " Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 17/19] common/mlx5: " Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 18/19] net/mlx5: " Tyler Retzlaff
2024-04-18 20:02 ` [PATCH v2 19/19] build: enable vla warnings on " Tyler Retzlaff
2024-05-06 18:18 ` [PATCH v3 00/19] remove use of VLAs for Windows Tyler Retzlaff
2024-05-06 18:18 ` [PATCH v3 01/19] eal: include header required for alloca Tyler Retzlaff
2024-05-06 18:18 ` [PATCH v3 02/19] eal/linux: remove use of VLAs Tyler Retzlaff
2024-05-06 18:18 ` [PATCH v3 03/19] eal/common: " Tyler Retzlaff
2024-05-07 0:42 ` Stephen Hemminger
2024-05-06 18:18 ` [PATCH v3 04/19] ethdev: remove use of VLAs for Windows built code Tyler Retzlaff
2024-05-06 18:18 ` [PATCH v3 05/19] hash: " Tyler Retzlaff
2024-05-06 18:18 ` [PATCH v3 06/19] hash/thash: " Tyler Retzlaff
2024-05-06 18:18 ` [PATCH v3 07/19] rcu: " Tyler Retzlaff
2024-05-06 18:18 ` [PATCH v3 08/19] gro: " Tyler Retzlaff
2024-05-07 0:47 ` Stephen Hemminger
2024-05-06 18:18 ` [PATCH v3 09/19] latencystats: " Tyler Retzlaff
2024-05-07 0:47 ` Stephen Hemminger
2024-05-06 18:18 ` [PATCH v3 10/19] lpm: " Tyler Retzlaff
2024-05-06 18:18 ` [PATCH v3 11/19] app/testpmd: " Tyler Retzlaff
2024-05-06 18:18 ` [PATCH v3 12/19] test: " Tyler Retzlaff
2024-05-06 18:18 ` [PATCH v3 13/19] common/idpf: " Tyler Retzlaff
2024-05-06 18:18 ` [PATCH v3 14/19] net/i40e: " Tyler Retzlaff
2024-05-06 18:18 ` [PATCH v3 15/19] net/ice: " Tyler Retzlaff
2024-05-06 18:18 ` [PATCH v3 16/19] net/ixgbe: " Tyler Retzlaff
2024-05-06 18:18 ` [PATCH v3 17/19] common/mlx5: " Tyler Retzlaff
2024-05-06 18:18 ` [PATCH v3 18/19] net/mlx5: " Tyler Retzlaff
2024-05-06 18:18 ` [PATCH v3 19/19] build: enable vla warnings on " Tyler Retzlaff
2024-05-07 2:53 ` [PATCH 1/2] lpm: remove unnecessary temporary VLA Stephen Hemminger
2024-05-07 2:53 ` Stephen Hemminger [this message]
2024-05-07 7:51 ` Bruce Richardson
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