slstatus: add cpu_iowait

This commit introduces the cpu_iowait item, this is the percentage
of cpu time spent waiting on disks. High numbers typically indicate
that your system is not responsive due to disk IO.
This commit also avoid sleeping inside the cpu_perc and cpu_iowait
functions: waiting in either one implies lost info for the other.

Signed-off-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>

diff --git a/config.def.h b/config.def.h
index 0e28d1e19a8c4dff0ed7d426dfe1e854cbf5fbef..637000880477bf5c645e2d7e2cd85054716e3acc 100644 (file)
--- a/config.def.h
+++ b/config.def.h
@@ -16,6 +16,7 @@ static const char unknown_str[] = "n/a";
  * battery_power        battery power usage             battery name
  * battery_state        battery charging state          battery name
  * cpu_perc             cpu usage in percent            NULL
+ * cpu_iowait           cpu iowait in percent           NULL
  * cpu_freq             cpu frequency in MHz            NULL
  * datetime             date and time                   format string
  * disk_free            free disk space in GB           mountpoint path

diff --git a/slstatus.c b/slstatus.c
index e69423b2c51bd3ca6873a24b837d7a098e25297c..cbc35a4369b9074e70d0c6d0b996fe6f5b608b5f 100644 (file)
--- a/slstatus.c
+++ b/slstatus.c
@@ -40,6 +40,7 @@ static const char *battery_power(const char *bat);
 static const char *battery_state(const char *bat);
 static const char *cpu_freq(void);
 static const char *cpu_perc(void);
+static const char *cpu_iowait(void);
 static const char *datetime(const char *fmt);
 static const char *disk_free(const char *mnt);
 static const char *disk_perc(const char *mnt);
@@ -177,26 +178,47 @@ cpu_freq(void)
 static const char *
 cpu_perc(void)
 {
-       struct timespec delay;
        int perc;
-       long double a[4], b[4];
+       static long double a[7];
+       static int valid;
+       long double b[7];
 
-       if (pscanf("/proc/stat", "%*s %Lf %Lf %Lf %Lf", &a[0], &a[1], &a[2],
-                  &a[3]) != 4) {
+       memcpy(b, a, sizeof(b));
+       if (pscanf("/proc/stat", "%*s %Lf %Lf %Lf %Lf %Lf %Lf %Lf", &a[0], &a[1], &a[2],
+                  &a[3], &a[4], &a[5], &a[6]) != 7) {
                return unknown_str;
        }
+       if (!valid) {
+               valid = 1;
+               return unknown_str;
+       }
+
+       perc = 100 * ((b[0]+b[1]+b[2]+b[5]+b[6]) - (a[0]+a[1]+a[2]+a[5]+a[6])) /
+              ((b[0]+b[1]+b[2]+b[3]+b[4]+b[5]+b[6]) - (a[0]+a[1]+a[2]+a[3]+a[4]+a[5]+a[6]));
 
-       delay.tv_sec = (interval / 2) / 1000;
-       delay.tv_nsec = ((interval / 2) % 1000) * 1000000;
-       nanosleep(&delay, NULL);
+       return bprintf("%d", perc);
+}
 
-       if (pscanf("/proc/stat", "%*s %Lf %Lf %Lf %Lf", &b[0], &b[1], &b[2],
-                  &b[3]) != 4) {
+static const char *
+cpu_iowait(void)
+{
+       int perc;
+       static int valid;
+       static long double a[7];
+       long double b[7];
+
+       memcpy(b, a, sizeof(b));
+       if (pscanf("/proc/stat", "%*s %Lf %Lf %Lf %Lf %Lf %Lf %Lf", &a[0], &a[1], &a[2],
+                  &a[3], &a[4], &a[5], &a[6]) != 7) {
+               return unknown_str;
+       }
+       if (!valid) {
+               valid = 1;
                return unknown_str;
        }
 
-       perc = 100 * ((b[0]+b[1]+b[2]) - (a[0]+a[1]+a[2])) /
-              ((b[0]+b[1]+b[2]+b[3]) - (a[0]+a[1]+a[2]+a[3]));
+       perc = 100 * ((b[4]) - (a[4])) /
+              ((b[0]+b[1]+b[2]+b[3]+b[4]+b[5]+b[6]) - (a[0]+a[1]+a[2]+a[3]+a[4]+a[5]+a[6]));
 
        return bprintf("%d", perc);
 }