On systems without ACPI, query the CPUidle sysfs interface for C-state
details. It uses the CPUIdle stateN/usage and stateN/time files for
the 'usage' and 'duration' values used for calculations in powertop.
For now, if both ACPI and CPUidle are present, it will read data from
the ACPI /proc interface instead of CPUidle, but if ACPI is not
present, it will fallback to CPUidle.
Tested against a CPUidle enabled 2.6.24 non-x86 kernel (TI OMAP3.)
Patch against powertop-1.9.
Signed-off-by: Kevin Hilman <khilman@xxxxxxxxxx>
diff -ruN powertop-1.9/powertop.c powertop-1.9-KJH/powertop.c
--- powertop-1.9/powertop.c 2008-01-30 17:24:27.000000000 -0800
+++ powertop-1.9-KJH/powertop.c 2008-01-30 21:02:54.000000000 -0800
@@ -35,6 +35,7 @@
#include <assert.h>
#include <locale.h>
#include <time.h>
+#include <sys/stat.h>
#include "powertop.h"
@@ -236,7 +237,7 @@
fclose(file);
}
-static void read_data(uint64_t * usage, uint64_t * duration)
+static void read_data_acpi(uint64_t * usage, uint64_t * duration)
{
DIR *dir;
struct dirent *entry;
@@ -286,6 +287,97 @@
closedir(dir);
}
+static void read_data_cpuidle(uint64_t * usage, uint64_t * duration)
+{
+ DIR *dir;
+ struct dirent *entry;
+ FILE *file = NULL;
+ char line[4096];
+ char filename[128], *f;
+ int len, clevel = 0;
+
+ memset(usage, 0, 64);
+ memset(duration, 0, 64);
+
+ dir = opendir("/sys/devices/system/cpu");
+ if (!dir)
+ return;
+
+ /* Loop over cpuN entries */
+ while ((entry = readdir(dir))) {
+ if (strlen(entry->d_name) < 3)
+ continue;
+
+ if (!isdigit(entry->d_name[3]))
+ continue;
+
+ len = sprintf(filename, "/sys/devices/system/cpu/%s/cpuidle",
+ entry->d_name);
+
+ dir = opendir(filename);
+ if (!dir)
+ return;
+
+ /* For each C-state, there is a stateX directory which
+ * contains a 'usage' and a 'time' (duration) file */
+ while ((entry = readdir(dir))) {
+ if (strlen(entry->d_name) < 3)
+ continue;
+ sprintf(filename + len, "/%s/usage", entry->d_name);
+ file = fopen(filename, "r");
+ if (!file)
+ continue;
+
+ memset(line, 0, 4096);
+ f = fgets(line, 4096, file);
+ fclose(file);
+ if (f == NULL)
+ break;
+
+ usage[clevel] += 1+strtoull(line, NULL, 10);
+
+ sprintf(filename + len, "/%s/time", entry->d_name);
+ file = fopen(filename, "r");
+ if (!file)
+ continue;
+
+ memset(line, 0, 4096);
+ f = fgets(line, 4096, file);
+ fclose(file);
+ if (f == NULL)
+ break;
+
+ duration[clevel] += 1+strtoull(line, NULL, 10);
+
+ clevel++;
+ if (clevel > maxcstate)
+ maxcstate = clevel;
+
+ }
+
+ }
+ closedir(dir);
+}
+
+static void read_data(uint64_t * usage, uint64_t * duration)
+{
+ int r;
+ struct stat s;
+
+ /* First, check for ACPI */
+ r = stat("/proc/acpi/processor", &s);
+ if (!r) {
+ read_data_acpi(usage, duration);
+ return;
+ }
+
+ /* Then check for CPUidle */
+ r = stat("/sys/devices/system/cpu/cpuidle", &s);
+ if (!r) {
+ read_data_cpuidle(usage, duration);
+ }
+}
+
void stop_timerstats(void)
{
FILE *file;
@@ -530,7 +622,7 @@
memset(&cstate_lines, 0, sizeof(cstate_lines));
topcstate = -4;
if (totalevents == 0 && maxcstate <= 1) {
- sprintf(cstate_lines[5],_("< Detailed C-state information is only available on Mobile CPUs (laptops) >\n"));
+ sprintf(cstate_lines[5],_("< Detailed C-state information is not available.>\n"));
} else {
double sleept, percentage;;
c0 = sysconf(_SC_NPROCESSORS_ONLN) * ticktime * 1000 * FREQ - totalticks;
-
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