Enable CPU frequency chart

[Compizfox]

I want to have the CPU clock frequency chart enabled in Netdata. If I'm not mistaken, this is handled by proc.plugin, which is enabled by default. However, my Netdata instance does not have the CPU frequency chart.

In the docs I found this statement:

If more than 50 cores are present in a system then CPU thermal throttling, frequency, and idle state charts are disabled.

The machine in question has a Threadripper 3970X (32 cores, 64 threads). Is it possible that the threads are counted as 'cores', and that is why the charts are disabled?

Is it possible to turn the charts back on using a config option?

[ilyam8]

i see that 50 limitation is hardcoded

netdata/collectors/proc.plugin/proc_stat.c

Lines 488 to 504 in 77749bb

	if(unlikely(do_cpu == -1)) {
	do_cpu = config_get_boolean("plugin:proc:/proc/stat", "cpu utilization", CONFIG_BOOLEAN_YES);
	do_cpu_cores = config_get_boolean("plugin:proc:/proc/stat", "per cpu core utilization", CONFIG_BOOLEAN_YES);
	do_interrupts = config_get_boolean("plugin:proc:/proc/stat", "cpu interrupts", CONFIG_BOOLEAN_YES);
	do_context = config_get_boolean("plugin:proc:/proc/stat", "context switches", CONFIG_BOOLEAN_YES);
	do_forks = config_get_boolean("plugin:proc:/proc/stat", "processes started", CONFIG_BOOLEAN_YES);
	do_processes = config_get_boolean("plugin:proc:/proc/stat", "processes running", CONFIG_BOOLEAN_YES);
	// give sane defaults based on the number of processors
	if(unlikely(processors > 50)) {
	// the system has too many processors
	keep_per_core_fds_open = CONFIG_BOOLEAN_NO;
	do_core_throttle_count = CONFIG_BOOLEAN_NO;
	do_package_throttle_count = CONFIG_BOOLEAN_NO;
	do_cpu_freq = CONFIG_BOOLEAN_NO;
	do_cpuidle = CONFIG_BOOLEAN_NO;
	}

[mfundul]

That's not a problem @ilyam8 .

The "cores" word is wrong in this document. In reality it's what linux calls "processors" or "CPUs". The computer architecture term would be "hardware threads".

If you want to enable all of the options that are automatically disabled due to high processor count in proc_stat module, you need to enable in netdata.conf section [plugin:proc:/proc/stat] the following boolean configuration options:

    keep per core files open = yes
    keep cpuidle files open = yes
    core_throttle_count = yes
    package_throttle_count = yes
    cpu frequency = yes
    cpu idle states = yes

As a result, you will have more charts, more CPU overhead and more open file descriptors from netdata.

[Compizfox]

Thanks for the quick responses!

The "cores" word is wrong in this document. In reality it's what linux calls "processors" or "CPUs". The computer architecture term would be "hardware threads".

Ah, right, like I suspected ;)

If you want to enable all of the options that are automatically disabled due to high processor count in proc_stat module you need to enable in netdata.conf section [plugin:proc:/proc/stat] the following boolean configuration options:

So it is possible to override this behaviour in the config. Thanks! I have set these options and the charts are working. I'll keep an eye on the performance impact.

[Compizfox]

Okay, quick second question: the clock frequency figures I see in the Netdata chart differ from those I obtain from /proc/cpuinfo under load.

In Netdata, the frequency doesn't exceed 3.7 Ghz (the CPU's base clock), but using /proc/cpuinfo I see it boosting to about 4.1 GHz.

[mfundul]

It's taken from /sys/devices/system/cpu/cpuX/cpufreq/scaling_cur_freq.

[netdata-community-bot]

This issue has been mentioned on the Netdata Community Forums. There might be relevant details there:

https://community.netdata.cloud/t/enable-cpu-frequency-chart-netdata-cpu-cpufreq/4336/1