Merging upstream version 1.45.3+dfsg.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 286 insertions, 0 deletions

diff --git a/src/collectors/ebpf.plugin/ebpf_softirq.c b/src/collectors/ebpf.plugin/ebpf_softirq.c
new file mode 100644
index 000000000..106ff4f29
--- /dev/null
+++ b/src/collectors/ebpf.plugin/ebpf_softirq.c
@@ -0,0 +1,286 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "ebpf.h"
+#include "ebpf_softirq.h"
+
+struct config softirq_config = { .first_section = NULL,
+    .last_section = NULL,
+    .mutex = NETDATA_MUTEX_INITIALIZER,
+    .index = { .avl_tree = { .root = NULL, .compar = appconfig_section_compare },
+        .rwlock = AVL_LOCK_INITIALIZER } };
+
+#define SOFTIRQ_MAP_LATENCY 0
+static ebpf_local_maps_t softirq_maps[] = {
+    {
+        .name = "tbl_softirq",
+        .internal_input = NETDATA_SOFTIRQ_MAX_IRQS,
+        .user_input = 0,
+        .type = NETDATA_EBPF_MAP_STATIC,
+        .map_fd = ND_EBPF_MAP_FD_NOT_INITIALIZED,
+#ifdef LIBBPF_MAJOR_VERSION
+        .map_type = BPF_MAP_TYPE_PERCPU_ARRAY
+#endif
+    },
+    /* end */
+    {
+        .name = NULL,
+        .internal_input = 0,
+        .user_input = 0,
+        .type = NETDATA_EBPF_MAP_CONTROLLER,
+        .map_fd = ND_EBPF_MAP_FD_NOT_INITIALIZED,
+#ifdef LIBBPF_MAJOR_VERSION
+        .map_type = BPF_MAP_TYPE_PERCPU_ARRAY
+#endif
+    }
+};
+
+#define SOFTIRQ_TP_CLASS_IRQ "irq"
+static ebpf_tracepoint_t softirq_tracepoints[] = {
+    {.enabled = false, .class = SOFTIRQ_TP_CLASS_IRQ, .event = "softirq_entry"},
+    {.enabled = false, .class = SOFTIRQ_TP_CLASS_IRQ, .event = "softirq_exit"},
+    /* end */
+    {.enabled = false, .class = NULL, .event = NULL}
+};
+
+// these must be in the order defined by the kernel:
+// https://elixir.bootlin.com/linux/v5.12.19/source/include/trace/events/irq.h#L13
+static softirq_val_t softirq_vals[] = {
+    {.name = "HI", .latency = 0},
+    {.name = "TIMER", .latency = 0},
+    {.name = "NET_TX", .latency = 0},
+    {.name = "NET_RX", .latency = 0},
+    {.name = "BLOCK", .latency = 0},
+    {.name = "IRQ_POLL", .latency = 0},
+    {.name = "TASKLET", .latency = 0},
+    {.name = "SCHED", .latency = 0},
+    {.name = "HRTIMER", .latency = 0},
+    {.name = "RCU", .latency = 0},
+};
+
+// tmp store for soft IRQ values we get from a per-CPU eBPF map.
+static softirq_ebpf_val_t *softirq_ebpf_vals = NULL;
+
+/**
+ * Obsolete global
+ *
+ * Obsolete global charts created by thread.
+ *
+ * @param em a pointer to `struct ebpf_module`
+ */
+static void ebpf_obsolete_softirq_global(ebpf_module_t *em)
+{
+    ebpf_write_chart_obsolete(NETDATA_EBPF_SYSTEM_GROUP,
+                              "softirq_latency",
+                              "",
+                              "Software IRQ latency",
+                              EBPF_COMMON_DIMENSION_MILLISECONDS,
+                              "softirqs",
+                              NETDATA_EBPF_CHART_TYPE_STACKED,
+                              NULL,
+                              NETDATA_CHART_PRIO_SYSTEM_SOFTIRQS+1,
+                              em->update_every);
+}
+
+/**
+ * Cleanup
+ *
+ * Clean up allocated memory.
+ *
+ * @param ptr thread data.
+ */
+static void softirq_cleanup(void *ptr)
+{
+    ebpf_module_t *em = (ebpf_module_t *)ptr;
+
+    if (em->enabled == NETDATA_THREAD_EBPF_FUNCTION_RUNNING) {
+        pthread_mutex_lock(&lock);
+
+        ebpf_obsolete_softirq_global(em);
+
+        pthread_mutex_unlock(&lock);
+        fflush(stdout);
+    }
+
+    ebpf_update_kernel_memory_with_vector(&plugin_statistics, em->maps, EBPF_ACTION_STAT_REMOVE);
+
+    if (em->objects) {
+        ebpf_unload_legacy_code(em->objects, em->probe_links);
+        em->objects = NULL;
+        em->probe_links = NULL;
+    }
+
+    for (int i = 0; softirq_tracepoints[i].class != NULL; i++) {
+        ebpf_disable_tracepoint(&softirq_tracepoints[i]);
+    }
+    freez(softirq_ebpf_vals);
+    softirq_ebpf_vals = NULL;
+
+    pthread_mutex_lock(&ebpf_exit_cleanup);
+    em->enabled = NETDATA_THREAD_EBPF_STOPPED;
+    ebpf_update_stats(&plugin_statistics, em);
+    pthread_mutex_unlock(&ebpf_exit_cleanup);
+}
+
+/*****************************************************************
+ *  MAIN LOOP
+ *****************************************************************/
+
+/**
+ * Read Latency Map
+ *
+ * Read data from kernel ring to plot for users.
+ *
+ * @param maps_per_core do I need to read all cores?
+ */
+static void softirq_read_latency_map(int maps_per_core)
+{
+    int fd = softirq_maps[SOFTIRQ_MAP_LATENCY].map_fd;
+    int i;
+    size_t length = sizeof(softirq_ebpf_val_t);
+    if (maps_per_core)
+        length *= ebpf_nprocs;
+
+    for (i = 0; i < NETDATA_SOFTIRQ_MAX_IRQS; i++) {
+        int test = bpf_map_lookup_elem(fd, &i, softirq_ebpf_vals);
+        if (unlikely(test < 0)) {
+            continue;
+        }
+
+        uint64_t total_latency = 0;
+        int cpu_i;
+        int end = (maps_per_core) ? ebpf_nprocs : 1;
+        for (cpu_i = 0; cpu_i < end; cpu_i++) {
+            total_latency += softirq_ebpf_vals[cpu_i].latency/1000;
+        }
+
+        softirq_vals[i].latency = total_latency;
+        memset(softirq_ebpf_vals, 0, length);
+    }
+}
+
+static void softirq_create_charts(int update_every)
+{
+    ebpf_create_chart(
+        NETDATA_EBPF_SYSTEM_GROUP,
+        "softirq_latency",
+        "Software IRQ latency",
+        EBPF_COMMON_DIMENSION_MILLISECONDS,
+        "softirqs",
+        NULL,
+        NETDATA_EBPF_CHART_TYPE_STACKED,
+        NETDATA_CHART_PRIO_SYSTEM_SOFTIRQS+1,
+        NULL, NULL, 0, update_every,
+        NETDATA_EBPF_MODULE_NAME_SOFTIRQ
+    );
+
+    fflush(stdout);
+}
+
+static void softirq_create_dims()
+{
+    uint32_t i;
+    for (i = 0; i < NETDATA_SOFTIRQ_MAX_IRQS; i++) {
+        ebpf_write_global_dimension(
+            softirq_vals[i].name, softirq_vals[i].name,
+            ebpf_algorithms[NETDATA_EBPF_INCREMENTAL_IDX]
+        );
+    }
+}
+
+static inline void softirq_write_dims()
+{
+    uint32_t i;
+    for (i = 0; i < NETDATA_SOFTIRQ_MAX_IRQS; i++) {
+        write_chart_dimension(softirq_vals[i].name, softirq_vals[i].latency);
+    }
+}
+
+/**
+* Main loop for this collector.
+*/
+static void softirq_collector(ebpf_module_t *em)
+{
+    softirq_ebpf_vals = callocz(ebpf_nprocs, sizeof(softirq_ebpf_val_t));
+
+    // create chart and static dims.
+    pthread_mutex_lock(&lock);
+    softirq_create_charts(em->update_every);
+    softirq_create_dims();
+    ebpf_update_stats(&plugin_statistics, em);
+    ebpf_update_kernel_memory_with_vector(&plugin_statistics, em->maps, EBPF_ACTION_STAT_ADD);
+    pthread_mutex_unlock(&lock);
+
+    // loop and read from published data until ebpf plugin is closed.
+    heartbeat_t hb;
+    heartbeat_init(&hb);
+    int update_every = em->update_every;
+    int counter = update_every - 1;
+    int maps_per_core = em->maps_per_core;
+    //This will be cancelled by its parent
+    uint32_t running_time = 0;
+    uint32_t lifetime = em->lifetime;
+    while (!ebpf_plugin_exit && running_time < lifetime) {
+        (void)heartbeat_next(&hb, USEC_PER_SEC);
+        if (ebpf_plugin_exit || ++counter != update_every)
+            continue;
+
+        counter = 0;
+        softirq_read_latency_map(maps_per_core);
+        pthread_mutex_lock(&lock);
+
+        // write dims now for all hitherto discovered IRQs.
+        ebpf_write_begin_chart(NETDATA_EBPF_SYSTEM_GROUP, "softirq_latency", "");
+        softirq_write_dims();
+        ebpf_write_end_chart();
+
+        pthread_mutex_unlock(&lock);
+
+        pthread_mutex_lock(&ebpf_exit_cleanup);
+        if (running_time && !em->running_time)
+            running_time = update_every;
+        else
+            running_time += update_every;
+
+        em->running_time = running_time;
+        pthread_mutex_unlock(&ebpf_exit_cleanup);
+    }
+}
+
+/*****************************************************************
+ *  EBPF SOFTIRQ THREAD
+ *****************************************************************/
+
+/**
+ * Soft IRQ latency thread.
+ *
+ * @param ptr a `ebpf_module_t *`.
+ * @return always NULL.
+ */
+void *ebpf_softirq_thread(void *ptr)
+{
+    netdata_thread_cleanup_push(softirq_cleanup, ptr);
+
+    ebpf_module_t *em = (ebpf_module_t *)ptr;
+    em->maps = softirq_maps;
+
+    if (ebpf_enable_tracepoints(softirq_tracepoints) == 0) {
+        goto endsoftirq;
+    }
+
+#ifdef LIBBPF_MAJOR_VERSION
+    ebpf_define_map_type(em->maps, em->maps_per_core, running_on_kernel);
+#endif
+    em->probe_links = ebpf_load_program(ebpf_plugin_dir, em, running_on_kernel, isrh, &em->objects);
+    if (!em->probe_links) {
+        goto endsoftirq;
+    }
+
+    softirq_collector(em);
+
+endsoftirq:
+    ebpf_update_disabled_plugin_stats(em);
+
+    netdata_thread_cleanup_pop(1);
+
+    return NULL;
+}