forked from Minki/linux
7bb4597295
Except for 'perf record', the other perf tools read events one by one
from the ring buffer using perf_mmap__read_forward(). But it only
supports non-overwrite mode.
Introduce perf_mmap__read_event() to support both non-overwrite and
overwrite mode.
Usage:
perf_mmap__read_init()
while(event = perf_mmap__read_event()) {
//process the event
perf_mmap__consume()
}
perf_mmap__read_done()
It cannot use perf_mmap__read_backward(). Because it always reads the
stale buffer which is already processed. Furthermore, the forward and
backward concepts have been removed. The perf_mmap__read_backward() will
be replaced and discarded later.
Signed-off-by: Kan Liang <kan.liang@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1516310792-208685-9-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
105 lines
2.9 KiB
C
105 lines
2.9 KiB
C
#ifndef __PERF_MMAP_H
|
|
#define __PERF_MMAP_H 1
|
|
|
|
#include <linux/compiler.h>
|
|
#include <linux/refcount.h>
|
|
#include <linux/types.h>
|
|
#include <asm/barrier.h>
|
|
#include <stdbool.h>
|
|
#include "auxtrace.h"
|
|
#include "event.h"
|
|
|
|
/**
|
|
* struct perf_mmap - perf's ring buffer mmap details
|
|
*
|
|
* @refcnt - e.g. code using PERF_EVENT_IOC_SET_OUTPUT to share this
|
|
*/
|
|
struct perf_mmap {
|
|
void *base;
|
|
int mask;
|
|
int fd;
|
|
refcount_t refcnt;
|
|
u64 prev;
|
|
struct auxtrace_mmap auxtrace_mmap;
|
|
char event_copy[PERF_SAMPLE_MAX_SIZE] __aligned(8);
|
|
};
|
|
|
|
/*
|
|
* State machine of bkw_mmap_state:
|
|
*
|
|
* .________________(forbid)_____________.
|
|
* | V
|
|
* NOTREADY --(0)--> RUNNING --(1)--> DATA_PENDING --(2)--> EMPTY
|
|
* ^ ^ | ^ |
|
|
* | |__(forbid)____/ |___(forbid)___/|
|
|
* | |
|
|
* \_________________(3)_______________/
|
|
*
|
|
* NOTREADY : Backward ring buffers are not ready
|
|
* RUNNING : Backward ring buffers are recording
|
|
* DATA_PENDING : We are required to collect data from backward ring buffers
|
|
* EMPTY : We have collected data from backward ring buffers.
|
|
*
|
|
* (0): Setup backward ring buffer
|
|
* (1): Pause ring buffers for reading
|
|
* (2): Read from ring buffers
|
|
* (3): Resume ring buffers for recording
|
|
*/
|
|
enum bkw_mmap_state {
|
|
BKW_MMAP_NOTREADY,
|
|
BKW_MMAP_RUNNING,
|
|
BKW_MMAP_DATA_PENDING,
|
|
BKW_MMAP_EMPTY,
|
|
};
|
|
|
|
struct mmap_params {
|
|
int prot, mask;
|
|
struct auxtrace_mmap_params auxtrace_mp;
|
|
};
|
|
|
|
int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd);
|
|
void perf_mmap__munmap(struct perf_mmap *map);
|
|
|
|
void perf_mmap__get(struct perf_mmap *map);
|
|
void perf_mmap__put(struct perf_mmap *map);
|
|
|
|
void perf_mmap__consume(struct perf_mmap *map, bool overwrite);
|
|
|
|
void perf_mmap__read_catchup(struct perf_mmap *md);
|
|
|
|
static inline u64 perf_mmap__read_head(struct perf_mmap *mm)
|
|
{
|
|
struct perf_event_mmap_page *pc = mm->base;
|
|
u64 head = READ_ONCE(pc->data_head);
|
|
rmb();
|
|
return head;
|
|
}
|
|
|
|
static inline void perf_mmap__write_tail(struct perf_mmap *md, u64 tail)
|
|
{
|
|
struct perf_event_mmap_page *pc = md->base;
|
|
|
|
/*
|
|
* ensure all reads are done before we write the tail out.
|
|
*/
|
|
mb();
|
|
pc->data_tail = tail;
|
|
}
|
|
|
|
union perf_event *perf_mmap__read_forward(struct perf_mmap *map);
|
|
union perf_event *perf_mmap__read_backward(struct perf_mmap *map);
|
|
|
|
union perf_event *perf_mmap__read_event(struct perf_mmap *map,
|
|
bool overwrite,
|
|
u64 *startp, u64 end);
|
|
|
|
int perf_mmap__push(struct perf_mmap *md, bool backward,
|
|
void *to, int push(void *to, void *buf, size_t size));
|
|
|
|
size_t perf_mmap__mmap_len(struct perf_mmap *map);
|
|
|
|
int perf_mmap__read_init(struct perf_mmap *md, bool overwrite,
|
|
u64 *startp, u64 *endp);
|
|
void perf_mmap__read_done(struct perf_mmap *map);
|
|
#endif /*__PERF_MMAP_H */
|