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-rw-r--r--collectors/idlejitter.plugin/Makefile.am8
-rw-r--r--collectors/idlejitter.plugin/README.md20
-rw-r--r--collectors/idlejitter.plugin/plugin_idlejitter.c92
-rw-r--r--collectors/idlejitter.plugin/plugin_idlejitter.h21
4 files changed, 141 insertions, 0 deletions
diff --git a/collectors/idlejitter.plugin/Makefile.am b/collectors/idlejitter.plugin/Makefile.am
new file mode 100644
index 0000000..161784b
--- /dev/null
+++ b/collectors/idlejitter.plugin/Makefile.am
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+AUTOMAKE_OPTIONS = subdir-objects
+MAINTAINERCLEANFILES = $(srcdir)/Makefile.in
+
+dist_noinst_DATA = \
+ README.md \
+ $(NULL)
diff --git a/collectors/idlejitter.plugin/README.md b/collectors/idlejitter.plugin/README.md
new file mode 100644
index 0000000..3703e2e
--- /dev/null
+++ b/collectors/idlejitter.plugin/README.md
@@ -0,0 +1,20 @@
+<!--
+title: "idlejitter.plugin"
+custom_edit_url: https://github.com/netdata/netdata/edit/master/collectors/idlejitter.plugin/README.md
+-->
+
+# idlejitter.plugin
+
+It works like this:
+
+A thread is spawned that requests to sleep for 20000 microseconds (20ms).
+When the system wakes it up, it measures how many microseconds have passed.
+The difference between the requested and the actual duration of the sleep, is the idle jitter.
+This is done at most 50 times per second, to ensure we have a good average.
+
+This number is useful:
+
+1. in real-time environments, when the CPU jitter can affect the quality of the service (like VoIP media gateways).
+2. in cloud infrastructure, at can pause the VM or container for a small duration to perform operations at the host.
+
+[![analytics](https://www.google-analytics.com/collect?v=1&aip=1&t=pageview&_s=1&ds=github&dr=https%3A%2F%2Fgithub.com%2Fnetdata%2Fnetdata&dl=https%3A%2F%2Fmy-netdata.io%2Fgithub%2Fcollectors%2Fidlejitter.plugin%2FREADME&_u=MAC~&cid=5792dfd7-8dc4-476b-af31-da2fdb9f93d2&tid=UA-64295674-3)](<>)
diff --git a/collectors/idlejitter.plugin/plugin_idlejitter.c b/collectors/idlejitter.plugin/plugin_idlejitter.c
new file mode 100644
index 0000000..c59541e
--- /dev/null
+++ b/collectors/idlejitter.plugin/plugin_idlejitter.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "plugin_idlejitter.h"
+
+#define CPU_IDLEJITTER_SLEEP_TIME_MS 20
+
+static void cpuidlejitter_main_cleanup(void *ptr) {
+ struct netdata_static_thread *static_thread = (struct netdata_static_thread *)ptr;
+ static_thread->enabled = NETDATA_MAIN_THREAD_EXITING;
+
+ info("cleaning up...");
+
+ static_thread->enabled = NETDATA_MAIN_THREAD_EXITED;
+}
+
+void *cpuidlejitter_main(void *ptr) {
+ netdata_thread_cleanup_push(cpuidlejitter_main_cleanup, ptr);
+
+ usec_t sleep_ut = config_get_number("plugin:idlejitter", "loop time in ms", CPU_IDLEJITTER_SLEEP_TIME_MS) * USEC_PER_MS;
+ if(sleep_ut <= 0) {
+ config_set_number("plugin:idlejitter", "loop time in ms", CPU_IDLEJITTER_SLEEP_TIME_MS);
+ sleep_ut = CPU_IDLEJITTER_SLEEP_TIME_MS * USEC_PER_MS;
+ }
+
+ RRDSET *st = rrdset_create_localhost(
+ "system"
+ , "idlejitter"
+ , NULL
+ , "idlejitter"
+ , NULL
+ , "CPU Idle Jitter"
+ , "microseconds lost/s"
+ , "idlejitter.plugin"
+ , NULL
+ , NETDATA_CHART_PRIO_SYSTEM_IDLEJITTER
+ , localhost->rrd_update_every
+ , RRDSET_TYPE_AREA
+ );
+ RRDDIM *rd_min = rrddim_add(st, "min", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+ RRDDIM *rd_max = rrddim_add(st, "max", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+ RRDDIM *rd_avg = rrddim_add(st, "average", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+
+ usec_t update_every_ut = localhost->rrd_update_every * USEC_PER_SEC;
+ struct timeval before, after;
+ unsigned long long counter;
+
+ for(counter = 0; 1 ;counter++) {
+ int iterations = 0;
+ usec_t error_total = 0,
+ error_min = 0,
+ error_max = 0,
+ elapsed = 0;
+
+ if(netdata_exit) break;
+
+ while(elapsed < update_every_ut) {
+ now_monotonic_high_precision_timeval(&before);
+ sleep_usec(sleep_ut);
+ now_monotonic_high_precision_timeval(&after);
+
+ usec_t dt = dt_usec(&after, &before);
+ elapsed += dt;
+
+ usec_t error = dt - sleep_ut;
+ error_total += error;
+
+ if(unlikely(!iterations))
+ error_min = error;
+ else if(error < error_min)
+ error_min = error;
+
+ if(error > error_max)
+ error_max = error;
+
+ iterations++;
+ }
+
+ if(netdata_exit) break;
+
+ if(iterations) {
+ if (likely(counter)) rrdset_next(st);
+ rrddim_set_by_pointer(st, rd_min, error_min);
+ rrddim_set_by_pointer(st, rd_max, error_max);
+ rrddim_set_by_pointer(st, rd_avg, error_total / iterations);
+ rrdset_done(st);
+ }
+ }
+
+ netdata_thread_cleanup_pop(1);
+ return NULL;
+}
+
diff --git a/collectors/idlejitter.plugin/plugin_idlejitter.h b/collectors/idlejitter.plugin/plugin_idlejitter.h
new file mode 100644
index 0000000..62fabea
--- /dev/null
+++ b/collectors/idlejitter.plugin/plugin_idlejitter.h
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef NETDATA_PLUGIN_IDLEJITTER_H
+#define NETDATA_PLUGIN_IDLEJITTER_H 1
+
+#include "../../daemon/common.h"
+
+#define NETDATA_PLUGIN_HOOK_IDLEJITTER \
+ { \
+ .name = "PLUGIN[idlejitter]", \
+ .config_section = CONFIG_SECTION_PLUGINS, \
+ .config_name = "idlejitter", \
+ .enabled = 1, \
+ .thread = NULL, \
+ .init_routine = NULL, \
+ .start_routine = cpuidlejitter_main \
+ },
+
+extern void *cpuidlejitter_main(void *ptr);
+
+#endif /* NETDATA_PLUGIN_IDLEJITTER_H */