add pressure (psi) collector

1 files changed, 47 insertions, 0 deletions

diff --git a/pressure.c b/pressure.c
new file mode 100644
index 0000000..2c8033c
--- /dev/null
+++ b/pressure.c
@@ -0,0 +1,47 @@
+#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 pressure_collect(scrape_req *req, void *ctx);
+
+const struct collector pressure_collector = {
+  .name = "pressure",
+  .collect = pressure_collect,
+};
+
+static void pressure_collect(scrape_req *req, void *ctx) {
+  (void) ctx;
+
+  FILE *f;
+  long long ms;
+
+  if ((f = fopen("/proc/pressure/cpu", "r"))) {
+    if (fscanf(f, "some %*[^t]total=%lld\n", &ms) == 1)
+      scrape_write(req, "node_cpu_waiting_seconds_total", 0, ms / 1e6);
+    fclose(f);
+  }
+
+  if ((f = fopen("/proc/pressure/memory", "r"))) {
+    if (fscanf(f, "some %*[^t]total=%lld\n", &ms) == 1)
+      scrape_write(req, "memory_waiting_seconds_total", 0, ms / 1e6);
+    if (fscanf(f, "full %*[^t]total=%lld\n", &ms) == 1)
+      scrape_write(req, "memory_stalled_seconds_total", 0, ms / 1e6);
+    fclose(f);
+  }
+
+  if ((f = fopen("/proc/pressure/io", "r"))) {
+    if (fscanf(f, "some %*[^t]total=%lld\n", &ms) == 1)
+      scrape_write(req, "io_waiting_seconds_total", 0, ms / 1e6);
+    if (fscanf(f, "full %*[^t]total=%lld\n", &ms) == 1)
+      scrape_write(req, "io_stalled_seconds_total", 0, ms / 1e6);
+    fclose(f);
+  }
+}