blob: 75368f9ea2e68e371d509b3f32e9fa6f2efefc7e [file] [log] [blame]
* Performance events:
* Copyright (C) 2008-2009, Thomas Gleixner <>
* Copyright (C) 2008-2011, Red Hat, Inc., Ingo Molnar
* Copyright (C) 2008-2011, Red Hat, Inc., Peter Zijlstra
* Data type definitions, declarations, prototypes.
* Started by: Thomas Gleixner and Ingo Molnar
* For licencing details see kernel-base/COPYING
#include <uapi/linux/perf_event.h>
* Kernel-internal data types and definitions:
# include <asm/perf_event.h>
# include <asm/local64.h>
struct perf_guest_info_callbacks {
int (*is_in_guest)(void);
int (*is_user_mode)(void);
unsigned long (*get_guest_ip)(void);
#include <asm/hw_breakpoint.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
#include <linux/spinlock.h>
#include <linux/hrtimer.h>
#include <linux/fs.h>
#include <linux/pid_namespace.h>
#include <linux/workqueue.h>
#include <linux/ftrace.h>
#include <linux/cpu.h>
#include <linux/irq_work.h>
#include <linux/static_key.h>
#include <linux/jump_label_ratelimit.h>
#include <linux/atomic.h>
#include <linux/sysfs.h>
#include <linux/perf_regs.h>
#include <linux/workqueue.h>
#include <asm/local.h>
struct perf_callchain_entry {
__u64 nr;
struct perf_raw_record {
u32 size;
void *data;
* branch stack layout:
* nr: number of taken branches stored in entries[]
* Note that nr can vary from sample to sample
* branches (to, from) are stored from most recent
* to least recent, i.e., entries[0] contains the most
* recent branch.
struct perf_branch_stack {
__u64 nr;
struct perf_branch_entry entries[0];
struct perf_regs_user {
__u64 abi;
struct pt_regs *regs;
struct task_struct;
* extra PMU register associated with an event
struct hw_perf_event_extra {
u64 config; /* register value */
unsigned int reg; /* register address or index */
int alloc; /* extra register already allocated */
int idx; /* index in shared_regs->regs[] */
struct event_constraint;
* struct hw_perf_event - performance event hardware details:
struct hw_perf_event {
union {
struct { /* hardware */
u64 config;
u64 last_tag;
unsigned long config_base;
unsigned long event_base;
int event_base_rdpmc;
int idx;
int last_cpu;
int flags;
struct hw_perf_event_extra extra_reg;
struct hw_perf_event_extra branch_reg;
struct event_constraint *constraint;
struct { /* software */
struct hrtimer hrtimer;
struct { /* tracepoint */
struct task_struct *tp_target;
/* for tp_event->class */
struct list_head tp_list;
struct { /* breakpoint */
* Crufty hack to avoid the chicken and egg
* problem hw_breakpoint has with context
* creation and event initalization.
struct task_struct *bp_target;
struct arch_hw_breakpoint info;
struct list_head bp_list;
int state;
local64_t prev_count;
u64 sample_period;
u64 last_period;
local64_t period_left;
u64 interrupts_seq;
u64 interrupts;
u64 freq_time_stamp;
u64 freq_count_stamp;
* hw_perf_event::state flags
#define PERF_HES_STOPPED 0x01 /* the counter is stopped */
#define PERF_HES_UPTODATE 0x02 /* event->count up-to-date */
#define PERF_HES_ARCH 0x04
struct perf_event;
* Common implementation detail of pmu::{start,commit,cancel}_txn
#define PERF_EVENT_TXN 0x1
* pmu::capabilities flags
* struct pmu - generic performance monitoring unit
struct pmu {
struct list_head entry;
struct module *module;
struct device *dev;
const struct attribute_group **attr_groups;
const char *name;
int type;
* various common per-pmu feature flags
int capabilities;
int * __percpu pmu_disable_count;
struct perf_cpu_context * __percpu pmu_cpu_context;
int task_ctx_nr;
int hrtimer_interval_ms;
u32 events_across_hotplug:1,
* Fully disable/enable this PMU, can be used to protect from the PMI
* as well as for lazy/batch writing of the MSRs.
void (*pmu_enable) (struct pmu *pmu); /* optional */
void (*pmu_disable) (struct pmu *pmu); /* optional */
* Try and initialize the event for this PMU.
* Should return -ENOENT when the @event doesn't match this PMU.
int (*event_init) (struct perf_event *event);
#define PERF_EF_START 0x01 /* start the counter when adding */
#define PERF_EF_RELOAD 0x02 /* reload the counter when starting */
#define PERF_EF_UPDATE 0x04 /* update the counter when stopping */
* Adds/Removes a counter to/from the PMU, can be done inside
* a transaction, see the ->*_txn() methods.
int (*add) (struct perf_event *event, int flags);
void (*del) (struct perf_event *event, int flags);
* Starts/Stops a counter present on the PMU. The PMI handler
* should stop the counter when perf_event_overflow() returns
* !0. ->start() will be used to continue.
void (*start) (struct perf_event *event, int flags);
void (*stop) (struct perf_event *event, int flags);
* Updates the counter value of the event.
void (*read) (struct perf_event *event);
* Group events scheduling is treated as a transaction, add
* group events as a whole and perform one schedulability test.
* If the test fails, roll back the whole group
* Start the transaction, after this ->add() doesn't need to
* do schedulability tests.
void (*start_txn) (struct pmu *pmu); /* optional */
* If ->start_txn() disabled the ->add() schedulability test
* then ->commit_txn() is required to perform one. On success
* the transaction is closed. On error the transaction is kept
* open until ->cancel_txn() is called.
int (*commit_txn) (struct pmu *pmu); /* optional */
* Will cancel the transaction, assumes ->del() is called
* for each successful ->add() during the transaction.
void (*cancel_txn) (struct pmu *pmu); /* optional */
* Will return the value for perf_event_mmap_page::index for this event,
* if no implementation is provided it will default to: event->hw.idx + 1.
int (*event_idx) (struct perf_event *event); /*optional */
* flush branch stack on context-switches (needed in cpu-wide mode)
void (*flush_branch_stack) (void);
* enum perf_event_active_state - the states of a event
enum perf_event_active_state {
struct file;
struct perf_sample_data;
typedef void (*perf_overflow_handler_t)(struct perf_event *,
struct perf_sample_data *,
struct pt_regs *regs);
enum perf_group_flag {
struct swevent_hlist {
struct hlist_head heads[SWEVENT_HLIST_SIZE];
struct rcu_head rcu_head;
#define PERF_ATTACH_GROUP 0x02
#define PERF_ATTACH_TASK 0x04
struct perf_cgroup;
struct ring_buffer;
* struct perf_event - performance event kernel representation:
struct perf_event {
* entry onto perf_event_context::event_list;
* modifications require ctx->lock
* RCU safe iterations.
struct list_head event_entry;
* XXX: group_entry and sibling_list should be mutually exclusive;
* either you're a sibling on a group, or you're the group leader.
* Rework the code to always use the same list element.
* Locked for modification by both ctx->mutex and ctx->lock; holding
* either sufficies for read.
struct list_head group_entry;
struct list_head sibling_list;
* We need storage to track the entries in perf_pmu_migrate_context; we
* cannot use the event_entry because of RCU and we want to keep the
* group in tact which avoids us using the other two entries.
struct list_head migrate_entry;
struct hlist_node hlist_entry;
struct list_head active_entry;
int nr_siblings;
int group_flags;
struct perf_event *group_leader;
* Protect the pmu, attributes and context of a group leader.
* Note: does not protect the pointer to the group_leader.
struct mutex group_leader_mutex;
struct pmu *pmu;
enum perf_event_active_state state;
unsigned int attach_state;
local64_t count;
atomic64_t child_count;
* These are the total time in nanoseconds that the event
* has been enabled (i.e. eligible to run, and the task has
* been scheduled in, if this is a per-task event)
* and running (scheduled onto the CPU), respectively.
* They are computed from tstamp_enabled, tstamp_running and
* tstamp_stopped when the event is in INACTIVE or ACTIVE state.
u64 total_time_enabled;
u64 total_time_running;
* These are timestamps used for computing total_time_enabled
* and total_time_running when the event is in INACTIVE or
* ACTIVE state, measured in nanoseconds from an arbitrary point
* in time.
* tstamp_enabled: the notional time when the event was enabled
* tstamp_running: the notional time when the event was scheduled on
* tstamp_stopped: in INACTIVE state, the notional time when the
* event was scheduled off.
u64 tstamp_enabled;
u64 tstamp_running;
u64 tstamp_stopped;
* timestamp shadows the actual context timing but it can
* be safely used in NMI interrupt context. It reflects the
* context time as it was when the event was last scheduled in.
* ctx_time already accounts for ctx->timestamp. Therefore to
* compute ctx_time for a sample, simply add perf_clock().
u64 shadow_ctx_time;
struct perf_event_attr attr;
u16 header_size;
u16 id_header_size;
u16 read_size;
struct hw_perf_event hw;
struct perf_event_context *ctx;
atomic_long_t refcount;
* These accumulate total time (in nanoseconds) that children
* events have been enabled and running, respectively.
atomic64_t child_total_time_enabled;
atomic64_t child_total_time_running;
* Protect attach/detach and child_list:
struct mutex child_mutex;
struct list_head child_list;
struct perf_event *parent;
int oncpu;
int cpu;
struct list_head owner_entry;
struct task_struct *owner;
/* mmap bits */
struct mutex mmap_mutex;
atomic_t mmap_count;
struct ring_buffer *rb;
struct list_head rb_entry;
unsigned long rcu_batches;
int rcu_pending;
/* poll related */
wait_queue_head_t waitq;
struct fasync_struct *fasync;
/* delayed work for NMIs and such */
int pending_wakeup;
int pending_kill;
int pending_disable;
struct irq_work pending;
atomic_t event_limit;
void (*destroy)(struct perf_event *);
struct rcu_head rcu_head;
struct pid_namespace *ns;
u64 id;
perf_overflow_handler_t overflow_handler;
void *overflow_handler_context;
struct ftrace_event_call *tp_event;
struct event_filter *filter;
struct ftrace_ops ftrace_ops;
struct perf_cgroup *cgrp; /* cgroup event is attach to */
int cgrp_defer_enabled;
enum perf_event_context_type {
* struct perf_event_context - event context structure
* Used as a container for task events and CPU events as well:
struct perf_event_context {
struct pmu *pmu;
enum perf_event_context_type type;
* Protect the states of the events in the list,
* nr_active, and the list:
raw_spinlock_t lock;
* Protect the list of events. Locking either mutex or lock
* is sufficient to ensure the list doesn't change; to change
* the list you need to lock both the mutex and the spinlock.
struct mutex mutex;
struct list_head pinned_groups;
struct list_head flexible_groups;
struct list_head event_list;
int nr_events;
int nr_active;
int is_active;
int nr_stat;
int nr_freq;
int rotate_disable;
atomic_t refcount;
struct task_struct *task;
* Context clock, runs when context enabled.
u64 time;
u64 timestamp;
* These fields let us detect when two contexts have both
* been cloned (inherited) from a common ancestor.
struct perf_event_context *parent_ctx;
u64 parent_gen;
u64 generation;
int pin_count;
int nr_cgroups; /* cgroup evts */
int nr_branch_stack; /* branch_stack evt */
struct rcu_head rcu_head;
struct delayed_work orphans_remove;
bool orphans_remove_sched;
* Number of contexts where an event can trigger:
* task, softirq, hardirq, nmi.
* struct perf_event_cpu_context - per cpu event context structure
struct perf_cpu_context {
struct perf_event_context ctx;
struct perf_event_context *task_ctx;
int active_oncpu;
int exclusive;
struct hrtimer hrtimer;
ktime_t hrtimer_interval;
struct list_head rotation_list;
struct pmu *unique_pmu;
struct perf_cgroup *cgrp;
struct perf_output_handle {
struct perf_event *event;
struct ring_buffer *rb;
unsigned long wakeup;
unsigned long size;
void *addr;
int page;
extern int perf_pmu_register(struct pmu *pmu, const char *name, int type);
extern void perf_pmu_unregister(struct pmu *pmu);
extern int perf_num_counters(void);
extern const char *perf_pmu_name(void);
extern void __perf_event_task_sched_in(struct task_struct *prev,
struct task_struct *task);
extern void __perf_event_task_sched_out(struct task_struct *prev,
struct task_struct *next);
extern int perf_event_init_task(struct task_struct *child);
extern void perf_event_exit_task(struct task_struct *child);
extern void perf_event_free_task(struct task_struct *task);
extern void perf_event_delayed_put(struct task_struct *task);
extern void perf_event_print_debug(void);
extern void perf_pmu_disable(struct pmu *pmu);
extern void perf_pmu_enable(struct pmu *pmu);
extern int perf_event_task_disable(void);
extern int perf_event_task_enable(void);
extern int perf_event_refresh(struct perf_event *event, int refresh);
extern void perf_event_update_userpage(struct perf_event *event);
extern int perf_event_release_kernel(struct perf_event *event);
extern struct perf_event *
perf_event_create_kernel_counter(struct perf_event_attr *attr,
int cpu,
struct task_struct *task,
perf_overflow_handler_t callback,
void *context);
extern void perf_pmu_migrate_context(struct pmu *pmu,
int src_cpu, int dst_cpu);
extern u64 perf_event_read_value(struct perf_event *event,
u64 *enabled, u64 *running);
extern struct dentry *perf_create_debug_dir(void);
struct perf_sample_data {
u64 type;
u64 ip;
struct {
u32 pid;
u32 tid;
} tid_entry;
u64 time;
u64 addr;
u64 id;
u64 stream_id;
struct {
u32 cpu;
u32 reserved;
} cpu_entry;
u64 period;
union perf_mem_data_src data_src;
struct perf_callchain_entry *callchain;
struct perf_raw_record *raw;
struct perf_branch_stack *br_stack;
struct perf_regs_user regs_user;
u64 stack_user_size;
u64 weight;
* Transaction flags for abort events:
u64 txn;
/* default value for data source */
#define PERF_MEM_NA (PERF_MEM_S(OP, NA) |\
static inline void perf_sample_data_init(struct perf_sample_data *data,
u64 addr, u64 period)
/* remaining struct members initialized in perf_prepare_sample() */
data->addr = addr;
data->raw = NULL;
data->br_stack = NULL;
data->period = period;
data->regs_user.abi = PERF_SAMPLE_REGS_ABI_NONE;
data->regs_user.regs = NULL;
data->stack_user_size = 0;
data->weight = 0;
data->data_src.val = PERF_MEM_NA;
data->txn = 0;
extern void perf_output_sample(struct perf_output_handle *handle,
struct perf_event_header *header,
struct perf_sample_data *data,
struct perf_event *event);
extern void perf_prepare_sample(struct perf_event_header *header,
struct perf_sample_data *data,
struct perf_event *event,
struct pt_regs *regs);
extern int perf_event_overflow(struct perf_event *event,
struct perf_sample_data *data,
struct pt_regs *regs);
static inline bool is_sampling_event(struct perf_event *event)
return event->attr.sample_period != 0;
* Return 1 for a software event, 0 for a hardware event
static inline int is_software_event(struct perf_event *event)
return event->pmu->task_ctx_nr == perf_sw_context;
extern struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX];
extern void __perf_sw_event(u32, u64, struct pt_regs *, u64);
#ifndef perf_arch_fetch_caller_regs
static inline void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip) { }
* Take a snapshot of the regs. Skip ip and frame pointer to
* the nth caller. We only need a few of the regs:
* - ip for PERF_SAMPLE_IP
* - cs for user_mode() tests
* - bp for callchains
* - eflags, for future purposes, just in case
static inline void perf_fetch_caller_regs(struct pt_regs *regs)
memset(regs, 0, sizeof(*regs));
perf_arch_fetch_caller_regs(regs, CALLER_ADDR0);
static __always_inline void
perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
struct pt_regs hot_regs;
if (static_key_false(&perf_swevent_enabled[event_id])) {
if (!regs) {
regs = &hot_regs;
__perf_sw_event(event_id, nr, regs, addr);
extern struct static_key_deferred perf_sched_events;
static inline void perf_event_task_sched_in(struct task_struct *prev,
struct task_struct *task)
if (static_key_false(&perf_sched_events.key))
__perf_event_task_sched_in(prev, task);
static inline void perf_event_task_sched_out(struct task_struct *prev,
struct task_struct *next)
if (static_key_false(&perf_sched_events.key))
__perf_event_task_sched_out(prev, next);
extern void perf_event_mmap(struct vm_area_struct *vma);
extern struct perf_guest_info_callbacks *perf_guest_cbs;
extern int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks);
extern int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks);
extern void perf_event_exec(void);
extern void perf_event_comm(struct task_struct *tsk, bool exec);
extern void perf_event_fork(struct task_struct *tsk);
/* Callchains */
DECLARE_PER_CPU(struct perf_callchain_entry, perf_callchain_entry);
extern void perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs);
extern void perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs);
static inline void perf_callchain_store(struct perf_callchain_entry *entry, u64 ip)
if (entry->nr < PERF_MAX_STACK_DEPTH)
entry->ip[entry->nr++] = ip;
extern int sysctl_perf_event_paranoid;
extern int sysctl_perf_event_mlock;
extern int sysctl_perf_event_sample_rate;
extern int sysctl_perf_cpu_time_max_percent;
extern void perf_sample_event_took(u64 sample_len_ns);
extern int perf_proc_update_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos);
extern int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos);
static inline bool perf_paranoid_any(void)
return sysctl_perf_event_paranoid > 2;
static inline bool perf_paranoid_tracepoint_raw(void)
return sysctl_perf_event_paranoid > -1;
static inline bool perf_paranoid_cpu(void)
return sysctl_perf_event_paranoid > 0;
static inline bool perf_paranoid_kernel(void)
return sysctl_perf_event_paranoid > 1;
extern void perf_event_init(void);
extern void perf_tp_event(u64 addr, u64 count, void *record,
int entry_size, struct pt_regs *regs,
struct hlist_head *head, int rctx,
struct task_struct *task);
extern void perf_bp_event(struct perf_event *event, void *data);
#ifndef perf_misc_flags
# define perf_misc_flags(regs) \
# define perf_instruction_pointer(regs) instruction_pointer(regs)
static inline bool has_branch_stack(struct perf_event *event)
return event->attr.sample_type & PERF_SAMPLE_BRANCH_STACK;
extern int perf_output_begin(struct perf_output_handle *handle,
struct perf_event *event, unsigned int size);
extern void perf_output_end(struct perf_output_handle *handle);
extern unsigned int perf_output_copy(struct perf_output_handle *handle,
const void *buf, unsigned int len);
extern unsigned int perf_output_skip(struct perf_output_handle *handle,
unsigned int len);
extern int perf_swevent_get_recursion_context(void);
extern void perf_swevent_put_recursion_context(int rctx);
extern u64 perf_swevent_set_period(struct perf_event *event);
extern void perf_event_enable(struct perf_event *event);
extern void perf_event_disable(struct perf_event *event);
extern int __perf_event_disable(void *info);
extern void perf_event_task_tick(void);
#else /* !CONFIG_PERF_EVENTS: */
static inline void
perf_event_task_sched_in(struct task_struct *prev,
struct task_struct *task) { }
static inline void
perf_event_task_sched_out(struct task_struct *prev,
struct task_struct *next) { }
static inline int perf_event_init_task(struct task_struct *child) { return 0; }
static inline void perf_event_exit_task(struct task_struct *child) { }
static inline void perf_event_free_task(struct task_struct *task) { }
static inline void perf_event_delayed_put(struct task_struct *task) { }
static inline void perf_event_print_debug(void) { }
static inline int perf_event_task_disable(void) { return -EINVAL; }
static inline int perf_event_task_enable(void) { return -EINVAL; }
static inline int perf_event_refresh(struct perf_event *event, int refresh)
return -EINVAL;
static inline void
perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) { }
static inline void
perf_bp_event(struct perf_event *event, void *data) { }
static inline int perf_register_guest_info_callbacks
(struct perf_guest_info_callbacks *callbacks) { return 0; }
static inline int perf_unregister_guest_info_callbacks
(struct perf_guest_info_callbacks *callbacks) { return 0; }
static inline void perf_event_mmap(struct vm_area_struct *vma) { }
static inline void perf_event_exec(void) { }
static inline void perf_event_comm(struct task_struct *tsk, bool exec) { }
static inline void perf_event_fork(struct task_struct *tsk) { }
static inline void perf_event_init(void) { }
static inline int perf_swevent_get_recursion_context(void) { return -1; }
static inline void perf_swevent_put_recursion_context(int rctx) { }
static inline u64 perf_swevent_set_period(struct perf_event *event) { return 0; }
static inline void perf_event_enable(struct perf_event *event) { }
static inline void perf_event_disable(struct perf_event *event) { }
static inline int __perf_event_disable(void *info) { return -1; }
static inline void perf_event_task_tick(void) { }
#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_NO_HZ_FULL)
extern bool perf_event_can_stop_tick(void);
static inline bool perf_event_can_stop_tick(void) { return true; }
extern void perf_restore_debug_store(void);
static inline void perf_restore_debug_store(void) { }
#define perf_output_put(handle, x) perf_output_copy((handle), &(x), sizeof(x))
* This has to have a higher priority than migration_notifier in sched/core.c.
#define perf_cpu_notifier(fn) \
do { \
static struct notifier_block fn##_nb = \
{ .notifier_call = fn, .priority = CPU_PRI_PERF }; \
unsigned long cpu = smp_processor_id(); \
unsigned long flags; \
cpu_notifier_register_begin(); \
fn(&fn##_nb, (unsigned long)CPU_UP_PREPARE, \
(void *)(unsigned long)cpu); \
local_irq_save(flags); \
fn(&fn##_nb, (unsigned long)CPU_STARTING, \
(void *)(unsigned long)cpu); \
local_irq_restore(flags); \
fn(&fn##_nb, (unsigned long)CPU_ONLINE, \
(void *)(unsigned long)cpu); \
__register_cpu_notifier(&fn##_nb); \
cpu_notifier_register_done(); \
} while (0)
* Bare-bones version of perf_cpu_notifier(), which doesn't invoke the
* callback for already online CPUs.
#define __perf_cpu_notifier(fn) \
do { \
static struct notifier_block fn##_nb = \
{ .notifier_call = fn, .priority = CPU_PRI_PERF }; \
__register_cpu_notifier(&fn##_nb); \
} while (0)
struct perf_pmu_events_attr {
struct device_attribute attr;
u64 id;
const char *event_str;
#define PMU_EVENT_ATTR(_name, _var, _id, _show) \
static struct perf_pmu_events_attr _var = { \
.attr = __ATTR(_name, 0444, _show, NULL), \
.id = _id, \
#define PMU_FORMAT_ATTR(_name, _format) \
static ssize_t \
_name##_show(struct device *dev, \
struct device_attribute *attr, \
char *page) \
{ \
BUILD_BUG_ON(sizeof(_format) >= PAGE_SIZE); \
return sprintf(page, _format "\n"); \
} \
static struct device_attribute format_attr_##_name = __ATTR_RO(_name)
#endif /* _LINUX_PERF_EVENT_H */