From: Stephen Hemminger <stephen@networkplumber.org>
To: dev@dpdk.org
Cc: Stephen Hemminger <stephen@networkplumber.org>,
Reshma Pattan <reshma.pattan@intel.com>
Subject: [PATCH v6 7/8] latencystats: add metric for number of samples
Date: Wed, 29 May 2024 15:54:44 -0700 [thread overview]
Message-ID: <20240529225732.442539-8-stephen@networkplumber.org> (raw)
In-Reply-To: <20240529225732.442539-1-stephen@networkplumber.org>
Keeping track of the number of samples is useful when doing
debug and testing to make sure that samples are actually happening.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
lib/latencystats/rte_latencystats.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/lib/latencystats/rte_latencystats.c b/lib/latencystats/rte_latencystats.c
index 8311adb411..e5a84fbd92 100644
--- a/lib/latencystats/rte_latencystats.c
+++ b/lib/latencystats/rte_latencystats.c
@@ -59,6 +59,7 @@ struct rte_latency_stats {
uint64_t avg_latency; /**< Average latency */
uint64_t max_latency; /**< Maximum latency */
uint64_t jitter; /** Latency variation */
+ uint64_t samples; /** Number of latency samples */
rte_spinlock_t lock; /** Latency calculation lock */
};
@@ -82,20 +83,26 @@ static const struct latency_stats_nameoff lat_stats_strings[] = {
{"avg_latency_ns", offsetof(struct rte_latency_stats, avg_latency), LATENCY_AVG_SCALE},
{"max_latency_ns", offsetof(struct rte_latency_stats, max_latency), 1},
{"jitter_ns", offsetof(struct rte_latency_stats, jitter), LATENCY_JITTER_SCALE},
+ {"samples", offsetof(struct rte_latency_stats, samples), 0},
};
-#define NUM_LATENCY_STATS (sizeof(lat_stats_strings) / \
- sizeof(lat_stats_strings[0]))
+#define NUM_LATENCY_STATS RTE_DIM(lat_stats_strings)
static void
latencystats_collect(uint64_t values[])
{
- unsigned int i;
+ unsigned int i, scale;
const uint64_t *stats;
for (i = 0; i < NUM_LATENCY_STATS; i++) {
stats = RTE_PTR_ADD(glob_stats, lat_stats_strings[i].offset);
- values[i] = floor(*stats / (cycles_per_ns * lat_stats_strings[i].scale));
+ scale = lat_stats_strings[i].scale;
+
+ /* used to mark samples which are not a time interval */
+ if (scale == 0)
+ values[i] = *stats;
+ else
+ values[i] = floor(*stats / (cycles_per_ns * scale));
}
}
@@ -173,7 +180,6 @@ calc_latency(uint16_t pid __rte_unused,
unsigned int i;
uint64_t now, latency;
static uint64_t prev_latency;
- static bool first_sample = true;
now = rte_rdtsc();
@@ -184,9 +190,7 @@ calc_latency(uint16_t pid __rte_unused,
latency = now - *timestamp_dynfield(pkts[i]);
- if (unlikely(first_sample)) {
- first_sample = false;
-
+ if (glob_stats->samples++ == 0) {
glob_stats->min_latency = latency;
glob_stats->max_latency = latency;
glob_stats->avg_latency = latency * 4;
--
2.43.0
next prev parent reply other threads:[~2024-05-29 22:58 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-08 19:50 [RFC] latencystats: performance overhaul Stephen Hemminger
2024-04-08 21:26 ` [PATCH v2] " Stephen Hemminger
2024-04-19 17:28 ` [PATCH v4 0/6] latencystats: cleanup Stephen Hemminger
2024-04-19 17:28 ` [PATCH v4 1/6] latencystats: replace use of VLA Stephen Hemminger
2024-04-19 17:28 ` [PATCH v4 2/6] latencystats: handle fractional cycles per ns Stephen Hemminger
2024-04-19 17:28 ` [PATCH v4 3/6] latencystats: do not use floating point Stephen Hemminger
2024-04-19 18:49 ` Morten Brørup
2024-04-19 22:45 ` Stephen Hemminger
2024-04-20 7:31 ` Morten Brørup
2024-04-19 17:28 ` [PATCH v4 4/6] latencystats: fix log messages Stephen Hemminger
2024-04-19 17:28 ` [PATCH v4 5/6] latencystats: update include files Stephen Hemminger
2024-04-19 17:28 ` [PATCH v4 6/6] latencystats: fix for pedantic warnings Stephen Hemminger
2024-04-22 15:21 ` [PATCH v5 0/9] latencystats: improve algorithms and tests Stephen Hemminger
2024-04-22 15:21 ` [PATCH v5 1/9] latencystats: replace use of VLA Stephen Hemminger
2024-04-22 15:21 ` [PATCH v5 2/9] latencystats: handle fractional cycles per ns Stephen Hemminger
2024-04-22 15:21 ` [PATCH v5 3/9] latencystats: do not use floating point Stephen Hemminger
2024-04-22 15:21 ` [PATCH v5 4/9] latencystats: fix log messages Stephen Hemminger
2024-04-22 15:21 ` [PATCH v5 5/9] latencystats: update include files Stephen Hemminger
2024-04-22 15:21 ` [PATCH v5 6/9] latencystats: enforce that unused callback function is NULL Stephen Hemminger
2024-04-22 15:21 ` [PATCH v5 7/9] latencystats: add metric for number of samples Stephen Hemminger
2024-04-22 15:21 ` [PATCH v5 8/9] test: use initialization in latencystats test Stephen Hemminger
2024-04-22 15:21 ` [PATCH v5 9/9] test: add more latencystats tests Stephen Hemminger
2024-05-29 22:54 ` [PATCH v6 0/8] latencystats: improvements to algorithm and test Stephen Hemminger
2024-05-29 22:54 ` [PATCH v6 1/8] latencystats: replace use of VLA Stephen Hemminger
2024-05-29 22:54 ` [PATCH v6 2/8] latencystats: handle fractional cycles per ns Stephen Hemminger
2024-05-29 22:54 ` [PATCH v6 3/8] latencystats: do not use floating point Stephen Hemminger
2024-05-29 22:54 ` [PATCH v6 4/8] latencystats: fix log messages Stephen Hemminger
2024-05-29 22:54 ` [PATCH v6 5/8] latencystats: update include files Stephen Hemminger
2024-05-29 22:54 ` [PATCH v6 6/8] latencystats: enforce that unused callback function is NULL Stephen Hemminger
2024-05-29 22:54 ` Stephen Hemminger [this message]
2024-05-29 22:54 ` [PATCH v6 8/8] test: update to latencystats tests Stephen Hemminger
2024-07-04 15:21 ` [PATCH v6 0/8] latencystats: improvements to algorithm and test David Marchand
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