perfmonctl -%uA0接口PMU

内容简介

#include <syscall.h> 
#include <perfmon.h> 
long perfmonctl(int%uA0fd, int%uA0cmd, void *arg, int%uA0narg)

描述

perfmonctl%uA0system call provides an interface to PMU (performance monitoring unit). PMU consists of PMD (performance monitoring data) registers and PMC (performance monitoring control) registers, where are gathered the hardware statistic.

perfmonctl%uA0will apply a function%uA0cmd%uA0to input arguments%uA0arg.%uA0The number of arguments is defined by input variable%uA0narg.%uA0fd%uA0specifies the perfmon context to operate on.

实现的%uA0cmd%uA0命令是：

标签

描述

PFM_CREATE_CONTEXT

%uA0

set up a context

perfmonctl(int fd, PFM_CREATE_CONTEXT , pfarg_context_t *ctxt,1)

The%uA0fd%uA0parameter is ignored. A new context is created as specified in%uA0ctxtand its file descriptor is returned in%uA0ctxt->ctx_fd.

The file descriptor, apart from passing it to%uA0perfmonctl, can be used to read event notifications (type%uA0pfm_msg_t) using the%uA0read(2) system call. Both%uA0select(2) and%uA0poll(2) can be used to wait for event notifications.

The context can be destroyed using the%uA0close(2) system call.

PFM_WRITE_PMCS

%uA0

set PMC registers

perfmonctl(int fd, PFM_WRITE_PMCS , pfarg_pmc_t *pmcs,n)

PFM_WRITE_PMDS

%uA0

set PMD registers

perfmonctl(int fd, PFM_WRITE_PMDS , pfarg_pmd_t *pmds,n)

PFM_READ_PMDS

%uA0

read PMD registers

perfmonctl(int fd, PFM_READ_PMDS , pfarg_pmd_t *pmds,n)

PFM_START

%uA0

start monitoring

perfmonctl(int fd,PFM_START,arg,1) 
perfmonctl(int fd,PFM_START,NULL,0)

PFM_STOP

%uA0

stop monitoring

perfmonctl(int fd,PFM_START,NULL,0)

PFM_LOAD_CONTEXT

%uA0

attach the context to a thread

perfmonctl(int fd, PFM_LOAD_CONTEXT ,pfarg_load_t *largs,1)

PFM_UNLOAD_CONTEXT

%uA0

detach the context from a thread

perfmonctl(int fd,PFM_UNLOAD_CONTEXT,NULL,0)

PFM_RESTART

%uA0

restart monitoring after recieving an overflow notification

perfmonctl(int fd,PFM_RESTART,NULL,0)

PFM_CREATE_EVTSETS

%uA0

create or modify event sets

perfmonctl(int fd,PFM_CREATE_EVTSETS,pfarg_setdesc_t*desc,n)

PFM_DELETE_EVTSETS

%uA0

delete event sets

perfmonctl(int fd,PFM_DELETE_EVTSET,pfarg_setdesc_t*desc,n)

PFM_GETINFO_EVTSETS

%uA0

get information about event sets

perfmonctl(int fd,PFM_GETINFO_EVTSETS,pfarg_setinfo_t*info,n)

%uA0

返回值

performctl%uA0returns zero when the operation is successful. On error -1 is returned and an error code is set in%uA0errno.

可用性

This syscall is implemented only on the IA-64 architecture since kernel 2.6.

%uA0

另请参阅

gprof (1)

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内容简介

描述

返回值

可用性

另请参阅