Documentation/ABI/testing/sysfs-kernel-metrics

What:		/sys/kernel/metrics/cpuidle_histogram/enable
Date:		November, 2023
Contact:	"Vishvam Mazumdar" <vmazumdar@google.com>
Description:
		This file used to enable logging CPU Idle histograms. Setting this to 1
		registers a callback for the cpu idle trace. This populates the values queried
		from /sys/kernel/metrics/cpuidle_histogram/cpuidle_histogram to create a
		histogram of the time each CPU spends in the valid idle states.
		0 means "disable" and 1 means "enable".

What:		/sys/kernel/metrics/cpuidle_histogram/reset
Date:		November, 2023
Contact:	"Vishvam Mazumdar" <vmazumdar@google.com>
Description:
		This file used to reset the values logging CPU Idle histograms. All values saved
		for the CPU Idle histogram will be reset to 0.
		Pass in any value to this node to trigger the reset.

What:		/sys/kernel/metrics/cpuidle_histogram
Date:		November, 2023
Contact:	"Vishvam Mazumdar" <vmazumdar@google.com>
Description:
		This file is a read only file that allows reading the CPU Idle histogram values
		at the current time. The CPU Idle histogram values keep track of the time each
		CPU spends in each idle state. The bin corresponding to each value is incremented
		with each new entry. The histogram bins are created as percentages of the target
		residency for each CPU (i.e. bin 1 = 0 to 25% target residency, bin 2 = 25 to 50
		% target residency, etc.).

What:		/sys/kernel/metrics/cpucluster_histogram
Date:		November, 2023
Contact:	"Vishvam Mazumdar" <vmazumdar@google.com>
Description:
		This file is a read only file that allows reading the CPU Cluster histogram values
		at the current time. The CPU Cluster histogram values keep track of the time each
		cluster spends in CPD and SICD. The bin corresponding to each value is incremented
		with each new entry. The histogram bins are created as percentages of the target
		residency for each cluster (i.e. bin 1 = 0 to 25% target residency, bin 2 = 25 to 50
		% target residency, etc.).