Access module

Enumerations
enum	AccessMode { ACCESSMODE_PERF = -1, ACCESSMODE_DIRECT = 0, ACCESSMODE_DAEMON = 1 }
	Enum for the access modes. More...

Functions
int	HPMaddThread (int cpu_id) __attribute__((visibility("default")))
	Add CPU to access module. More...
void	HPMfinalize () __attribute__((visibility("default")))
	Close connections. More...
int	HPMinit () __attribute__((visibility("default")))
	Initialize access module. More...
void	HPMmode (int mode) __attribute__((visibility("default")))
	Set access mode. More...

Detailed Description

Enumeration Type Documentation

enum AccessMode

Enum for the access modes.

LIKWID supports multiple access modes to the MSR and PCI performance monitoring registers. For direct access the user must have enough priviledges to access the MSR and PCI devices. The daemon mode forwards the operations to a daemon with higher priviledges.

Enumerator
ACCESSMODE_PERF	Access performance monitoring through perf_event kernel interface.
ACCESSMODE_DIRECT	Access performance monitoring registers directly.
ACCESSMODE_DAEMON	Use the access daemon to access the registers.

Function Documentation

int HPMaddThread

(

int

cpu_id

)

Add CPU to access module.

Add the given CPU to the access module. This opens the commnunication to either the MSR/PCI files or the access daemon.

Parameters

[in]

cpu_id

CPU that should be enabled for measurements

Returns

error code (0 for success, -ENODEV if access cannot be initialized

void HPMfinalize

(

)

Close connections.

Close the connections to the MSR/PCI files or the access daemon

int HPMinit

(

)

Initialize access module.

Initialize the module internals to either the MSR/PCI files or the access daemon

Returns

error code (0 for sccess)

void HPMmode

(

int

mode

)

Set access mode.

Sets the mode how the MSR and PCI registers should be accessed. 0 for direct access (propably root priviledges required) and 1 for accesses through the access daemon. It must be called before HPMinit()

Parameters

[in]

mode

(0=direct, 1=daemon)