From 1cac55cc60784b1d498d23343709519c2c92b365 Mon Sep 17 00:00:00 2001
From: malc <av1474@comtv.ru>
Date: Fri, 31 Aug 2007 00:57:36 +0400
Subject: [PATCH] Initial version of idlestat

---
 idlestat.c | 86 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 idlestat.c

diff --git a/idlestat.c b/idlestat.c
new file mode 100644
index 0000000..10b6a45
--- /dev/null
+++ b/idlestat.c
@@ -0,0 +1,86 @@
+#define _GNU_SOURCE
+#include <err.h>
+#include <time.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <alloca.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/time.h>
+#include <sys/sysinfo.h>
+
+static double now (void)
+{
+    struct timeval tv;
+
+    if (gettimeofday (&tv, NULL))
+        err (1, "gettimeofday");
+    return tv.tv_sec + tv.tv_usec * 1e-6;
+}
+
+static void idlenow (int fd, int nprocs, double *p)
+{
+    struct timeval tv;
+    size_t n = nprocs * sizeof (tv);
+    ssize_t m;
+    struct timeval *buf;
+    int i;
+
+    buf = alloca (n);
+    if (!buf) errx (1, "alloca failed");
+
+    m = read (fd, buf, n);
+    if (n - m) err (1, "read [n=%zu, m=%zi]", n, m);
+
+    for (i = 0; i < nprocs; ++i)
+        p[i] = buf[i].tv_sec + buf[i].tv_usec * 1e-6;
+}
+
+int main (int argc, char **argv)
+{
+    int fd;
+    int nprocs;
+    double *idle;
+    int flip = 0;
+    double *curr, *prev;
+
+    (void) argc;
+    (void) argv;
+
+    nprocs = get_nprocs ();
+    if (nprocs <= 0) errx (1, "get_nprocs returned %d", nprocs);
+
+    idle = malloc (2 * nprocs * sizeof (idle[0]));
+    if (!idle) errx (1, "malloc %zu failed", 2 * nprocs * sizeof (idle[0]));
+
+    fd = open ("/dev/itc", O_RDONLY);
+    if (fd < 0) errx (1, "open /dev/itc");
+
+    idlenow (fd, nprocs, idle);
+
+    flip = 0;
+    curr = &idle[nprocs];
+    prev = idle;
+
+    for (;;) {
+        int i;
+        double s, e, d, *t;
+
+        s = now ();
+        idlenow (fd, nprocs, prev);
+        sleep (1);
+        e = now ();
+        d = e - s;
+        idlenow (fd, nprocs, curr);
+
+        for (i = 0; i < nprocs; ++i) {
+            double di = curr[i] - prev[i];
+
+            printf ("cpu%d load - %.2f%%\n", i, 100.0 * (1.0 - di / d));
+        }
+
+        t = curr;
+        curr = prev;
+        prev = t;
+    }
+}
-- 
2.11.4.GIT