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 #ifdef HAVE_AIO_SUPPORT
  10 #include <aio.h>
  11 #endif
  12 #include "auxtrace.h"
  13 #include "event.h"
  14
  15 struct aiocb;
  16 /**
  17  * struct perf_mmap - perf's ring buffer mmap details
  18  *
  19  * @refcnt - e.g. code using PERF_EVENT_IOC_SET_OUTPUT to share this
  20  */
  21 struct perf_mmap {
  22         void             *base;
  23         int              mask;
  24         int              fd;
  25         int              cpu;
  26         refcount_t       refcnt;
  27         u64              prev;
  28         u64              start;
  29         u64              end;
  30         bool             overwrite;
  31         struct auxtrace_mmap auxtrace_mmap;
  32         char             event_copy[PERF_SAMPLE_MAX_SIZE] __aligned(8);
  33 #ifdef HAVE_AIO_SUPPORT
  34         struct {
  35                 void             **data;
  36                 struct aiocb     *cblocks;
  37                 struct aiocb     **aiocb;
  38                 int              nr_cblocks;
  39         } aio;
  40 #endif
  41         cpu_set_t       affinity_mask;
  42 };
  43
  44 /*
  45  * State machine of bkw_mmap_state:
  46  *
  47  *                     .________________(forbid)_____________.
  48  *                     |                                     V
  49  * NOTREADY --(0)--> RUNNING --(1)--> DATA_PENDING --(2)--> EMPTY
  50  *                     ^  ^              |   ^               |
  51  *                     |  |__(forbid)____/   |___(forbid)___/|
  52  *                     |                                     |
  53  *                      \_________________(3)_______________/
  54  *
  55  * NOTREADY     : Backward ring buffers are not ready
  56  * RUNNING      : Backward ring buffers are recording
  57  * DATA_PENDING : We are required to collect data from backward ring buffers
  58  * EMPTY        : We have collected data from backward ring buffers.
  59  *
  60  * (0): Setup backward ring buffer
  61  * (1): Pause ring buffers for reading
  62  * (2): Read from ring buffers
  63  * (3): Resume ring buffers for recording
  64  */
  65 enum bkw_mmap_state {
  66         BKW_MMAP_NOTREADY,
  67         BKW_MMAP_RUNNING,
  68         BKW_MMAP_DATA_PENDING,
  69         BKW_MMAP_EMPTY,
  70 };
  71
  72 struct mmap_params {
  73         int                         prot, mask, nr_cblocks, affinity;
  74         struct auxtrace_mmap_params auxtrace_mp;
  75 };
  76
  77 int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd, int cpu);
  78 void perf_mmap__munmap(struct perf_mmap *map);
  79
  80 void perf_mmap__get(struct perf_mmap *map);
  81 void perf_mmap__put(struct perf_mmap *map);
  82
  83 void perf_mmap__consume(struct perf_mmap *map);
  84
  85 static inline u64 perf_mmap__read_head(struct perf_mmap *mm)
  86 {
  87         return ring_buffer_read_head(mm->base);
  88 }
  89
  90 static inline void perf_mmap__write_tail(struct perf_mmap *md, u64 tail)
  91 {
  92         ring_buffer_write_tail(md->base, tail);
  93 }
  94
  95 union perf_event *perf_mmap__read_forward(struct perf_mmap *map);
  96
  97 union perf_event *perf_mmap__read_event(struct perf_mmap *map);
  98
  99 int perf_mmap__push(struct perf_mmap *md, void *to,
 100                     int push(struct perf_mmap *map, void *to, void *buf, size_t size));
 101 #ifdef HAVE_AIO_SUPPORT
 102 int perf_mmap__aio_push(struct perf_mmap *md, void *to, int idx,
 103                         int push(void *to, struct aiocb *cblock, void *buf, size_t size, off_t off),
 104                         off_t *off);
 105 #else
 106 static inline int perf_mmap__aio_push(struct perf_mmap *md __maybe_unused, void *to __maybe_unused, int idx __maybe_unused,
 107         int push(void *to, struct aiocb *cblock, void *buf, size_t size, off_t off) __maybe_unused,
 108         off_t *off __maybe_unused)
 109 {
 110         return 0;
 111 }
 112 #endif
 113
 114 size_t perf_mmap__mmap_len(struct perf_mmap *map);
 115
 116 int perf_mmap__read_init(struct perf_mmap *md);
 117 void perf_mmap__read_done(struct perf_mmap *map);
 118 #endif /*__PERF_MMAP_H */