tools/perf/util/mmap.h

   1 #ifndef __PERF_MMAP_H
   2 #define __PERF_MMAP_H 1
   3
   4 #include <linux/compiler.h>
   5 #include <linux/refcount.h>
   6 #include <linux/types.h>
   7 #include <linux/ring_buffer.h>
   8 #include <stdbool.h>
   9 #include <pthread.h> // for cpu_set_t
  10 #ifdef HAVE_AIO_SUPPORT
  11 #include <aio.h>
  12 #endif
  13 #include "auxtrace.h"
  14 #include "event.h"
  15
  16 struct aiocb;
  17 /**
  18  * struct perf_mmap - perf's ring buffer mmap details
  19  *
  20  * @refcnt - e.g. code using PERF_EVENT_IOC_SET_OUTPUT to share this
  21  */
  22 struct perf_mmap {
  23         void             *base;
  24         int              mask;
  25         int              fd;
  26         int              cpu;
  27         refcount_t       refcnt;
  28         u64              prev;
  29         u64              start;
  30         u64              end;
  31         bool             overwrite;
  32         struct auxtrace_mmap auxtrace_mmap;
  33         char             event_copy[PERF_SAMPLE_MAX_SIZE] __aligned(8);
  34 #ifdef HAVE_AIO_SUPPORT
  35         struct {
  36                 void             **data;
  37                 struct aiocb     *cblocks;
  38                 struct aiocb     **aiocb;
  39                 int              nr_cblocks;
  40         } aio;
  41 #endif
  42         cpu_set_t       affinity_mask;
  43         u64             flush;
  44         void            *data;
  45         int             comp_level;
  46 };
  47
  48 /*
  49  * State machine of bkw_mmap_state:
  50  *
  51  *                     .________________(forbid)_____________.
  52  *                     |                                     V
  53  * NOTREADY --(0)--> RUNNING --(1)--> DATA_PENDING --(2)--> EMPTY
  54  *                     ^  ^              |   ^               |
  55  *                     |  |__(forbid)____/   |___(forbid)___/|
  56  *                     |                                     |
  57  *                      \_________________(3)_______________/
  58  *
  59  * NOTREADY     : Backward ring buffers are not ready
  60  * RUNNING      : Backward ring buffers are recording
  61  * DATA_PENDING : We are required to collect data from backward ring buffers
  62  * EMPTY        : We have collected data from backward ring buffers.
  63  *
  64  * (0): Setup backward ring buffer
  65  * (1): Pause ring buffers for reading
  66  * (2): Read from ring buffers
  67  * (3): Resume ring buffers for recording
  68  */
  69 enum bkw_mmap_state {
  70         BKW_MMAP_NOTREADY,
  71         BKW_MMAP_RUNNING,
  72         BKW_MMAP_DATA_PENDING,
  73         BKW_MMAP_EMPTY,
  74 };
  75
  76 struct mmap_params {
  77         int prot, mask, nr_cblocks, affinity, flush, comp_level;
  78         struct auxtrace_mmap_params auxtrace_mp;
  79 };
  80
  81 int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd, int cpu);
  82 void perf_mmap__munmap(struct perf_mmap *map);
  83
  84 void perf_mmap__get(struct perf_mmap *map);
  85 void perf_mmap__put(struct perf_mmap *map);
  86
  87 void perf_mmap__consume(struct perf_mmap *map);
  88
  89 static inline u64 perf_mmap__read_head(struct perf_mmap *mm)
  90 {
  91         return ring_buffer_read_head(mm->base);
  92 }
  93
  94 static inline void perf_mmap__write_tail(struct perf_mmap *md, u64 tail)
  95 {
  96         ring_buffer_write_tail(md->base, tail);
  97 }
  98
  99 union perf_event *perf_mmap__read_forward(struct perf_mmap *map);
 100
 101 union perf_event *perf_mmap__read_event(struct perf_mmap *map);
 102
 103 int perf_mmap__push(struct perf_mmap *md, void *to,
 104                     int push(struct perf_mmap *map, void *to, void *buf, size_t size));
 105
 106 size_t perf_mmap__mmap_len(struct perf_mmap *map);
 107
 108 int perf_mmap__read_init(struct perf_mmap *md);
 109 void perf_mmap__read_done(struct perf_mmap *map);
 110 #endif /*__PERF_MMAP_H */