add schedstat collector

1 files changed, 45 insertions, 0 deletions

diff --git a/schedstat.c b/schedstat.c
new file mode 100644
index 0000000..985ce5c
--- /dev/null
+++ b/schedstat.c
@@ -0,0 +1,45 @@
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#include "scrape.h"
+#include "util.h"
+
+// size of input buffer for paths and lines
+#define BUF_SIZE 256
+
+static void schedstat_collect(scrape_req *req, void *ctx);
+
+const struct collector schedstat_collector = {
+  .name = "schedstat",
+  .collect = schedstat_collect,
+};
+
+static void schedstat_collect(scrape_req *req, void *ctx) {
+  (void) ctx;
+
+  FILE *f = fopen("/proc/schedstat", "r");
+  if (!f)
+    return;
+
+  char cpu[8];
+  long long running, waiting, timeslices;
+
+  char line[BUF_SIZE];
+  while(fgets_line(line, sizeof line, f)) {
+    if (sscanf(line, "cpu%[0-9] %*d %*d %*d %*d %*d %*d %lld %lld %lld\n",
+        cpu, &running, &waiting, &timeslices) == 4) {
+      struct label labels[] = {
+        { .key = "cpu", .value = cpu },
+        LABEL_END,
+      };
+      scrape_write(req, "node_schedstat_running_seconds_total", labels, running / 1e9);
+      scrape_write(req, "node_schedstat_waiting_seconds_total", labels, waiting / 1e9);
+      scrape_write(req, "node_schedstat_timeslices_total", labels, (double)timeslices);
+    }
+  }
+
+  fclose(f);
+}