"Pallipadi, Venkatesh" <[EMAIL PROTECTED]> writes:
>>
>>"Pallipadi, Venkatesh" <[EMAIL PROTECTED]> writes:
>>
>>> Nice timing for the patch. I am working on cpuidle patches that will
>>> add things like C1 idle residency time in /sysfs and was asking
>>> Arjan about switching powertop to use cpuidle interfaces :-).
>>
>>Great! My platform reports residency for all the states in sysfs
>>already, so powertop using sysfs is very useful to me.
>>
>>> One major comment is that with the patch C-state timing in powertop
>>> seems to be off, Due to different units of time in /proc/acpi and
>>> sysfs cpuidle. /proc/acpi C-state timings are in ACPI PM timer
>>> ticks and cpuidle exports it in micro-seconds.
>>
>>Yes, the percentage numbers are indeed off. I was just noticing the
>>same problem. I'm working right now on changing those calculations to
>>use usecs instead of ticks.
>>
>>I assume the hardcoded frequency in powertop (3579.545) is the
>>frequency of the ACPI timer? I'm pretty ignorant of ACPI, but am
>>guessing that's what those calculations are for.
>
> Yes. That hardcoded freq number is coming from ACPI PM timer frequency.
>
That being the case, the following patch makes the residency
calculations work using either usecs for CPUidle or ACPI ticks.
Basically, just setting FREQ=1000 make the calculations work out for
usecs.
Now I'm seeing correct residency percentages on my platform using
CPUidle.
Kevin
--- powertop-1.9/powertop.c 2008-01-30 17:24:27.000000000 -0800
+++ powertop-1.9-KJH/powertop.c 2008-01-31 16:58:20.000000000 -0800
@@ -35,6 +35,7 @@
#include <assert.h>
#include <locale.h>
#include <time.h>
+#include <sys/stat.h>
#include "powertop.h"
@@ -62,7 +63,8 @@
struct irqdata interrupts[IRQCOUNT];
-#define FREQ 3579.545
+#define FREQ_ACPI 3579.545
+static unsigned long FREQ;
int nostats;
@@ -236,7 +238,7 @@
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 +288,106 @@
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;
+ unsigned long usecs, ticks_per_sec = 32768, usecs_per_sec = 1000000;
+
+ 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;
+
+ clevel = 0;
+
+ /* 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);
+
+ /* perform residency calculations based on ACPI timer */
+ FREQ = FREQ_ACPI;
+ return;
+ }
+
+ /* Then check for CPUidle */
+ r = stat("/sys/devices/system/cpu/cpuidle", &s);
+ if (!r) {
+ read_data_cpuidle(usage, duration);
+
+ /* perform residency calculations based on usecs */
+ FREQ = 1000;
+ }
+}
+
void stop_timerstats(void)
{
FILE *file;
@@ -530,7 +632,7 @@
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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