android_kernel_google_msm/include/linux/perf_counter.h
Peter Zijlstra 925d519ab8 perf_counter: unify and fix delayed counter wakeup
While going over the wakeup code I noticed delayed wakeups only work
for hardware counters but basically all software counters rely on
them.

This patch unifies and generalizes the delayed wakeup to fix this
issue.

Since we're dealing with NMI context bits here, use a cmpxchg() based
single link list implementation to track counters that have pending
wakeups.

[ This should really be generic code for delayed wakeups, but since we
  cannot use cmpxchg()/xchg() in generic code, I've let it live in the
  perf_counter code. -- Eric Dumazet could use it to aggregate the
  network wakeups. ]

Furthermore, the x86 method of using TIF flags was flawed in that its
quite possible to end up setting the bit on the idle task, loosing the
wakeup.

The powerpc method uses per-cpu storage and does appear to be
sufficient.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Orig-LKML-Reference: <20090330171023.153932974@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06 09:30:36 +02:00

482 lines
12 KiB
C

/*
* Performance counters:
*
* Copyright(C) 2008, Thomas Gleixner <tglx@linutronix.de>
* Copyright(C) 2008, Red Hat, Inc., Ingo Molnar
*
* Data type definitions, declarations, prototypes.
*
* Started by: Thomas Gleixner and Ingo Molnar
*
* For licencing details see kernel-base/COPYING
*/
#ifndef _LINUX_PERF_COUNTER_H
#define _LINUX_PERF_COUNTER_H
#include <linux/types.h>
#include <linux/ioctl.h>
#include <asm/byteorder.h>
/*
* User-space ABI bits:
*/
/*
* hw_event.type
*/
enum perf_event_types {
PERF_TYPE_HARDWARE = 0,
PERF_TYPE_SOFTWARE = 1,
PERF_TYPE_TRACEPOINT = 2,
/*
* available TYPE space, raw is the max value.
*/
PERF_TYPE_RAW = 128,
};
/*
* Generalized performance counter event types, used by the hw_event.event_id
* parameter of the sys_perf_counter_open() syscall:
*/
enum hw_event_ids {
/*
* Common hardware events, generalized by the kernel:
*/
PERF_COUNT_CPU_CYCLES = 0,
PERF_COUNT_INSTRUCTIONS = 1,
PERF_COUNT_CACHE_REFERENCES = 2,
PERF_COUNT_CACHE_MISSES = 3,
PERF_COUNT_BRANCH_INSTRUCTIONS = 4,
PERF_COUNT_BRANCH_MISSES = 5,
PERF_COUNT_BUS_CYCLES = 6,
PERF_HW_EVENTS_MAX = 7,
};
/*
* Special "software" counters provided by the kernel, even if the hardware
* does not support performance counters. These counters measure various
* physical and sw events of the kernel (and allow the profiling of them as
* well):
*/
enum sw_event_ids {
PERF_COUNT_CPU_CLOCK = 0,
PERF_COUNT_TASK_CLOCK = 1,
PERF_COUNT_PAGE_FAULTS = 2,
PERF_COUNT_CONTEXT_SWITCHES = 3,
PERF_COUNT_CPU_MIGRATIONS = 4,
PERF_COUNT_PAGE_FAULTS_MIN = 5,
PERF_COUNT_PAGE_FAULTS_MAJ = 6,
PERF_SW_EVENTS_MAX = 7,
};
/*
* IRQ-notification data record type:
*/
enum perf_counter_record_type {
PERF_RECORD_SIMPLE = 0,
PERF_RECORD_IRQ = 1,
PERF_RECORD_GROUP = 2,
};
#define __PERF_COUNTER_MASK(name) \
(((1ULL << PERF_COUNTER_##name##_BITS) - 1) << \
PERF_COUNTER_##name##_SHIFT)
#define PERF_COUNTER_RAW_BITS 1
#define PERF_COUNTER_RAW_SHIFT 63
#define PERF_COUNTER_RAW_MASK __PERF_COUNTER_MASK(RAW)
#define PERF_COUNTER_CONFIG_BITS 63
#define PERF_COUNTER_CONFIG_SHIFT 0
#define PERF_COUNTER_CONFIG_MASK __PERF_COUNTER_MASK(CONFIG)
#define PERF_COUNTER_TYPE_BITS 7
#define PERF_COUNTER_TYPE_SHIFT 56
#define PERF_COUNTER_TYPE_MASK __PERF_COUNTER_MASK(TYPE)
#define PERF_COUNTER_EVENT_BITS 56
#define PERF_COUNTER_EVENT_SHIFT 0
#define PERF_COUNTER_EVENT_MASK __PERF_COUNTER_MASK(EVENT)
/*
* Bits that can be set in hw_event.read_format to request that
* reads on the counter should return the indicated quantities,
* in increasing order of bit value, after the counter value.
*/
enum perf_counter_read_format {
PERF_FORMAT_TOTAL_TIME_ENABLED = 1,
PERF_FORMAT_TOTAL_TIME_RUNNING = 2,
};
/*
* Hardware event to monitor via a performance monitoring counter:
*/
struct perf_counter_hw_event {
/*
* The MSB of the config word signifies if the rest contains cpu
* specific (raw) counter configuration data, if unset, the next
* 7 bits are an event type and the rest of the bits are the event
* identifier.
*/
__u64 config;
__u64 irq_period;
__u64 record_type;
__u64 read_format;
__u64 disabled : 1, /* off by default */
nmi : 1, /* NMI sampling */
inherit : 1, /* children inherit it */
pinned : 1, /* must always be on PMU */
exclusive : 1, /* only group on PMU */
exclude_user : 1, /* don't count user */
exclude_kernel : 1, /* ditto kernel */
exclude_hv : 1, /* ditto hypervisor */
exclude_idle : 1, /* don't count when idle */
include_tid : 1, /* include the tid */
__reserved_1 : 54;
__u32 extra_config_len;
__u32 __reserved_4;
__u64 __reserved_2;
__u64 __reserved_3;
};
/*
* Ioctls that can be done on a perf counter fd:
*/
#define PERF_COUNTER_IOC_ENABLE _IO('$', 0)
#define PERF_COUNTER_IOC_DISABLE _IO('$', 1)
/*
* Structure of the page that can be mapped via mmap
*/
struct perf_counter_mmap_page {
__u32 version; /* version number of this structure */
__u32 compat_version; /* lowest version this is compat with */
__u32 lock; /* seqlock for synchronization */
__u32 index; /* hardware counter identifier */
__s64 offset; /* add to hardware counter value */
__u32 data_head; /* head in the data section */
};
struct perf_event_header {
__u32 type;
__u32 size;
};
enum perf_event_type {
PERF_EVENT_IP = 0,
PERF_EVENT_GROUP = 1,
__PERF_EVENT_TID = 0x100,
};
#ifdef __KERNEL__
/*
* Kernel-internal data types and definitions:
*/
#ifdef CONFIG_PERF_COUNTERS
# include <asm/perf_counter.h>
#endif
#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 <asm/atomic.h>
struct task_struct;
static inline u64 perf_event_raw(struct perf_counter_hw_event *hw_event)
{
return hw_event->config & PERF_COUNTER_RAW_MASK;
}
static inline u64 perf_event_config(struct perf_counter_hw_event *hw_event)
{
return hw_event->config & PERF_COUNTER_CONFIG_MASK;
}
static inline u64 perf_event_type(struct perf_counter_hw_event *hw_event)
{
return (hw_event->config & PERF_COUNTER_TYPE_MASK) >>
PERF_COUNTER_TYPE_SHIFT;
}
static inline u64 perf_event_id(struct perf_counter_hw_event *hw_event)
{
return hw_event->config & PERF_COUNTER_EVENT_MASK;
}
/**
* struct hw_perf_counter - performance counter hardware details:
*/
struct hw_perf_counter {
#ifdef CONFIG_PERF_COUNTERS
union {
struct { /* hardware */
u64 config;
unsigned long config_base;
unsigned long counter_base;
int nmi;
unsigned int idx;
};
union { /* software */
atomic64_t count;
struct hrtimer hrtimer;
};
};
atomic64_t prev_count;
u64 irq_period;
atomic64_t period_left;
#endif
};
struct perf_counter;
/**
* struct hw_perf_counter_ops - performance counter hw ops
*/
struct hw_perf_counter_ops {
int (*enable) (struct perf_counter *counter);
void (*disable) (struct perf_counter *counter);
void (*read) (struct perf_counter *counter);
};
/**
* enum perf_counter_active_state - the states of a counter
*/
enum perf_counter_active_state {
PERF_COUNTER_STATE_ERROR = -2,
PERF_COUNTER_STATE_OFF = -1,
PERF_COUNTER_STATE_INACTIVE = 0,
PERF_COUNTER_STATE_ACTIVE = 1,
};
struct file;
struct perf_mmap_data {
struct rcu_head rcu_head;
int nr_pages;
atomic_t wakeup;
atomic_t head;
struct perf_counter_mmap_page *user_page;
void *data_pages[0];
};
struct perf_wakeup_entry {
struct perf_wakeup_entry *next;
};
/**
* struct perf_counter - performance counter kernel representation:
*/
struct perf_counter {
#ifdef CONFIG_PERF_COUNTERS
struct list_head list_entry;
struct list_head event_entry;
struct list_head sibling_list;
int nr_siblings;
struct perf_counter *group_leader;
const struct hw_perf_counter_ops *hw_ops;
enum perf_counter_active_state state;
enum perf_counter_active_state prev_state;
atomic64_t count;
/*
* These are the total time in nanoseconds that the counter
* has been enabled (i.e. eligible to run, and the task has
* been scheduled in, if this is a per-task counter)
* and running (scheduled onto the CPU), respectively.
*
* They are computed from tstamp_enabled, tstamp_running and
* tstamp_stopped when the counter 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 counter is in INACTIVE or
* ACTIVE state, measured in nanoseconds from an arbitrary point
* in time.
* tstamp_enabled: the notional time when the counter was enabled
* tstamp_running: the notional time when the counter was scheduled on
* tstamp_stopped: in INACTIVE state, the notional time when the
* counter was scheduled off.
*/
u64 tstamp_enabled;
u64 tstamp_running;
u64 tstamp_stopped;
struct perf_counter_hw_event hw_event;
struct hw_perf_counter hw;
struct perf_counter_context *ctx;
struct task_struct *task;
struct file *filp;
struct perf_counter *parent;
struct list_head child_list;
/*
* These accumulate total time (in nanoseconds) that children
* counters 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 mutex;
int oncpu;
int cpu;
/* mmap bits */
struct mutex mmap_mutex;
atomic_t mmap_count;
struct perf_mmap_data *data;
/* poll related */
wait_queue_head_t waitq;
/* optional: for NMIs */
struct perf_wakeup_entry wakeup;
void (*destroy)(struct perf_counter *);
struct rcu_head rcu_head;
#endif
};
/**
* struct perf_counter_context - counter context structure
*
* Used as a container for task counters and CPU counters as well:
*/
struct perf_counter_context {
#ifdef CONFIG_PERF_COUNTERS
/*
* Protect the states of the counters in the list,
* nr_active, and the list:
*/
spinlock_t lock;
/*
* Protect the list of counters. 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 counter_list;
struct list_head event_list;
int nr_counters;
int nr_active;
int is_active;
struct task_struct *task;
/*
* time_now is the current time in nanoseconds since an arbitrary
* point in the past. For per-task counters, this is based on the
* task clock, and for per-cpu counters it is based on the cpu clock.
* time_lost is an offset from the task/cpu clock, used to make it
* appear that time only passes while the context is scheduled in.
*/
u64 time_now;
u64 time_lost;
#endif
};
/**
* struct perf_counter_cpu_context - per cpu counter context structure
*/
struct perf_cpu_context {
struct perf_counter_context ctx;
struct perf_counter_context *task_ctx;
int active_oncpu;
int max_pertask;
int exclusive;
/*
* Recursion avoidance:
*
* task, softirq, irq, nmi context
*/
int recursion[4];
};
/*
* Set by architecture code:
*/
extern int perf_max_counters;
#ifdef CONFIG_PERF_COUNTERS
extern const struct hw_perf_counter_ops *
hw_perf_counter_init(struct perf_counter *counter);
extern void perf_counter_task_sched_in(struct task_struct *task, int cpu);
extern void perf_counter_task_sched_out(struct task_struct *task, int cpu);
extern void perf_counter_task_tick(struct task_struct *task, int cpu);
extern void perf_counter_init_task(struct task_struct *child);
extern void perf_counter_exit_task(struct task_struct *child);
extern void perf_counter_do_pending(void);
extern void perf_counter_print_debug(void);
extern void perf_counter_unthrottle(void);
extern u64 hw_perf_save_disable(void);
extern void hw_perf_restore(u64 ctrl);
extern int perf_counter_task_disable(void);
extern int perf_counter_task_enable(void);
extern int hw_perf_group_sched_in(struct perf_counter *group_leader,
struct perf_cpu_context *cpuctx,
struct perf_counter_context *ctx, int cpu);
extern void perf_counter_update_userpage(struct perf_counter *counter);
extern void perf_counter_output(struct perf_counter *counter,
int nmi, struct pt_regs *regs);
/*
* Return 1 for a software counter, 0 for a hardware counter
*/
static inline int is_software_counter(struct perf_counter *counter)
{
return !perf_event_raw(&counter->hw_event) &&
perf_event_type(&counter->hw_event) != PERF_TYPE_HARDWARE;
}
extern void perf_swcounter_event(u32, u64, int, struct pt_regs *);
#else
static inline void
perf_counter_task_sched_in(struct task_struct *task, int cpu) { }
static inline void
perf_counter_task_sched_out(struct task_struct *task, int cpu) { }
static inline void
perf_counter_task_tick(struct task_struct *task, int cpu) { }
static inline void perf_counter_init_task(struct task_struct *child) { }
static inline void perf_counter_exit_task(struct task_struct *child) { }
static inline void perf_counter_do_pending(void) { }
static inline void perf_counter_print_debug(void) { }
static inline void perf_counter_unthrottle(void) { }
static inline void hw_perf_restore(u64 ctrl) { }
static inline u64 hw_perf_save_disable(void) { return 0; }
static inline int perf_counter_task_disable(void) { return -EINVAL; }
static inline int perf_counter_task_enable(void) { return -EINVAL; }
static inline void
perf_swcounter_event(u32 event, u64 nr, int nmi, struct pt_regs *regs) { }
#endif
#endif /* __KERNEL__ */
#endif /* _LINUX_PERF_COUNTER_H */