fuchsia.perfmon.cpu

PROTOCOLS

Controller

Defined in fuchsia.perfmon.cpu/perfmon.fidl

GetProperties

Fetch the performance monitor properties of the system.

Request

Name	Type

Response

Name	Type
properties	Properties

Initialize

Create a trace, allocating the needed trace buffers and other resources. "other resources" is basically a catch-all for other things that will be needed. This does not include reserving the events, that is done later by StageConfig().

Request

Name	Type
allocation	Allocation

Response

Name	Type
result	Controller_Initialize_Result

Terminate

Free all trace buffers and any other resources allocated for the trace. This is also done when the connection is closed. Tracing is first stopped if not already stopped. May be called multiple times.

Request

Name	Type

Response

Name	Type

GetAllocation

Return the trace allocation configuration, if there is one.

Request

Name	Type

Response

Name	Type
allocation	Allocation?

StageConfig

Stage performance monitor specification for a cpu. Must be called with data collection off and after Initialize(). Note: This doesn't actually configure the h/w, this just stages the values for subsequent use by Start().

Request

Name	Type
config	Config

Response

Name	Type
result	Controller_StageConfig_Result

GetConfig

Fetch performance monitor specification for a cpu, if it exists. Must be called with data collection off and after StageConfig().

Request

Name	Type

Response

Name	Type
config	Config?

GetBufferHandle

Return a handle of a trace buffer, if it exists, and if descriptor is valid. descriptor is (0, 1, 2, ..., num_buffers-1)

Request

Name	Type
descriptor	uint32

Response

Name	Type
vmo	handle<vmo>?

Start

Turn on data collection. Must be called after Initialize() + StageConfig() and with data collection off.

Request

Name	Type

Response

Name	Type
result	Controller_Start_Result

Stop

Turn off data collection. May be called any time after Initialize() has been called and before Terminate(). If called at other times the call is ignored. May be called multiple times.

Request

Name	Type

Response

Name	Type

STRUCTS

Controller_Initialize_Response

generated

Name	Type	Description	Default

Controller_StageConfig_Response

generated

Name	Type	Description	Default

Controller_Start_Response

generated

Name	Type	Description	Default

Properties

Defined in fuchsia.perfmon.cpu/perfmon.fidl

The properties of this system.

Name	Type	Description	Default
api_version	uint16	S/W API version = API_VERSION.	No default
pm_version	uint16	The H/W Performance Monitor version. This is the version defined by the architecture.	No default
max_num_events	uint16	The maximum number of events that can be simultaneously supported. The combination of events that can be simultaneously supported is architecture/model specific.	No default
max_num_fixed_events	uint16	The maximum number of fixed events that can be simultaneously supported, and their maximum width. These values are for informational/display purposes.	No default
max_fixed_counter_width	uint16		No default
max_num_programmable_events	uint16	The maximum number of programmable events that can be simultaneously supported, and their maximum width. These values are for informational/display purposes.	No default
max_programmable_counter_width	uint16		No default
max_num_misc_events	uint16	The maximum number of misc events that can be simultaneously supported, and their maximum width. These values are for informational/display purposes.	No default
max_misc_counter_width	uint16		No default
flags	PropertyFlags	Various flags.	No default

EventConfig

Defined in fuchsia.perfmon.cpu/perfmon.fidl

Name	Type	Description	Default
event	EventId	Event to collect data for. The values are architecture specific ids. Each event may appear at most once.	No default
rate	EventRate	Sampling rate. If rate is non-zero then when the event gets this many hits data is collected (e.g., pc, time). The rate can be non-zero for counting based events only. If rate is zero then: If there is a timebase event then data for this event is collected when data for the timebase event is collected. Otherwise data for the event is collected once, when tracing stops.	No default
flags	EventConfigFlags	Flags for the event.	No default

Config

Defined in fuchsia.perfmon.cpu/perfmon.fidl

Passed to StageConfig() to select the data to be collected.

Name	Type	Description	Default
events	[32]	Events to collect data for.	No default

Allocation

Defined in fuchsia.perfmon.cpu/perfmon.fidl

The allocation configuration for a data collection run. This is generally the first call to allocate resources for a trace, "trace" is used generically here: == "data collection run".

Name	Type	Description	Default
num_buffers	uint32	The number of buffers to allocate for trace data. This must be #cpus for now.	No default
buffer_size_in_pages	uint32	The size of each buffer in 4K pages. Each cpu gets same buffer size.	No default

UNIONS

Controller_Initialize_Result

generated

Name	Type	Description
response	Controller_Initialize_Response
err	zx/status

Controller_StageConfig_Result

generated

Name	Type	Description
response	Controller_StageConfig_Response
err	zx/status

Controller_Start_Result

generated

Name	Type	Description
response	Controller_Start_Response
err	zx/status

BITS

PropertyFlags

Type: uint64

Name	Value	Description
HAS_LAST_BRANCH	1	The architecture supports LBR records (Last Branch Records).

EventConfigFlags

Type: uint32

Name	Value	Description
COLLECT_OS	1	Collect data when running in kernel mode.
COLLECT_USER	2	Collect data when running in userspace mode.
COLLECT_PC	4	Collect aspace+pc values.
IS_TIMEBASE	8	If set for an event then the event is used as the "timebase": data for events with a zero rate is collected when data for the timebase event is collected. It is an error to have this set and have the event's rate be zero. At most one event may be the timebase event.
COLLECT_LAST_BRANCH	16	Collect the available set of last branches. Branch data is emitted as LastBranch records. This is only available when the underlying system supports it.

CONSTANTS

Name	Value	Type	Description
API_VERSION	0	uint16
MAX_NUM_EVENTS	32	uint16	The maximum number of events we support simultaneously. Typically the h/w supports less than this, e.g., 7 or so.

TYPE ALIASES

Name	Value	Description
EventRate	uint32
EventId	uint16