Cpufreq doesn't show correct CPU frequency with intel_pstate

[zaps166]

I've got i7 3770k CPU and intel_pstate driver at powersave governor. The cpufreq applet shows always 1.6GHz, but the CPU frequency is changing during CPU load.

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[monsta]

Please file separate bug reports about each issue - makes it easier for us to track and handle.

[zaps166]

Ok, this is done.

[paraboul]

Same issue here. Stuck at 500mhz (for every CPU) while cpupower freauency-info shows the correct value.

[monsta]

I can't reproduce this - but I have an old CPU, Core 2 Duo...

[zaps166]

Ok, I know what is wrong! "intel_pstate" is not supported by this applet, so that why it doesn't work. I switched to "acpi-cpufreq" (intel_pstate=disable in kernel command line) and it works properly (but it should really be able to show entire CPU in one, especially if you want to change governor... #174).
@monsta: hmm, C2D is too old for this driver, so it will be difficult to fix it without testing...

[raveit65]

found a kernel doc about intel_pstate https://www.kernel.org/doc/Documentation/cpu-freq/intel-pstate.txt
Looks like SandyBridge procs support intel_pstate.

[zaps166]

@raveit65: Yes, Sandy Bridge and newer CPUs.

[monsta]

Ok, I suspected that... so I need to upgrade my system or buy some modern laptop 😄

[zaps166]

I looked here: https://github.com/mate-desktop/mate-applets/blob/master/cpufreq/src/cpufreq-monitor-sysfs.c#L67

and I looked also to this virtual directory, e.g. into "scaling_cur_freq" file - the value changes while I'm pressing "F5" in text editor (intel_pstate), but applet shows only 1,60 (without unit). Maybe this is a simple bug to fix?

[monsta]

Interesting. But is 1.60 a valid value for that processor (e.g. for minimum frequency)?

[monsta]

Also check what's in this file:

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

My system has ondemand setting there. It's also displayed in the tooltip of the applet.

[zaps166]

In:

/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

I have powersave or performance (depending on chosen governor).

On Powersave the applet shows 1.6GHz, on Performance - 4.1GHz (Turbo + OC in UEFI/BIOS). But both of them dynamically changes the clock in range 1.6GHz - 4.1GHz. On performance the time/threshold is lower than powersave - that is the difference on "intel_pstate" (AFAIK). Applet shows only one value (the lowest for powersave, the highest for performance). I can change the governor by applet in "intel_pstate" - so this works properly.

[monsta]

Ok, thanks, it's more clear to me now. So, the code does the same thing it always did before:

    if (g_ascii_strcasecmp (governor, "userspace") == 0) {
        path = g_strdup_printf (CPUFREQ_SYSFS_BASE_PATH,
                    cpu, monitor_sysfs_files[SCALING_SETSPEED]);
    } else if (g_ascii_strcasecmp (governor, "powersave") == 0) {
        path = g_strdup_printf (CPUFREQ_SYSFS_BASE_PATH,
                    cpu, monitor_sysfs_files[SCALING_MIN]);
    } else if (g_ascii_strcasecmp (governor, "performance") == 0) {
        path = g_strdup_printf (CPUFREQ_SYSFS_BASE_PATH,
                    cpu, monitor_sysfs_files[SCALING_MAX]);
    } else { /* Ondemand, Conservative, ... */
        path = g_strdup_printf (CPUFREQ_SYSFS_BASE_PATH,
                    cpu, monitor_sysfs_files[SCALING_CUR_FREQ]);
    }

Basically, it only reads scaling_cur_freq file when the governor is set to ondemand (to be precise, when it's not userspace or powersave or performance). I've looked upstream (in gnome-applets) - the code is the same there too.

[zaps166]

As far as I can remember performance runs at max. speed, powersave runs at min. speed and ondemand(and similar) dynamically scales the CPU on acpi-cpufreq. Modern governors can dynamically change the CPU frequency and them may have different names.
For me it should do an update on every governor or leave it as is for acpi-cpufreq and for other - always read current frequency.