libust/channels.h

   1 #ifndef _LTT_CHANNELS_H
   2 #define _LTT_CHANNELS_H
   3
   4 /*
   5  * Copyright (C) 2008 Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca)
   6  *
   7  * Dynamic tracer channel allocation.
   8  */
   9
  10 #include <linux/limits.h>
  11 //ust// #include <linux/kref.h>
  12 //ust// #include <linux/list.h>
  13 #include <errno.h>
  14
  15 #include "kernelcompat.h"
  16 #include "kref.h"
  17
  18 #define EVENTS_PER_CHANNEL      65536
  19
  20 struct ltt_trace_struct;
  21 struct rchan_buf;
  22
  23 struct ltt_channel_struct {
  24         /* First 32 bytes cache-hot cacheline */
  25         struct ltt_trace_struct *trace;
  26         void *buf;
  27         void *trans_channel_data;
  28         int overwrite:1;
  29         int active:1;
  30         unsigned int n_subbufs_order;
  31         unsigned long commit_count_mask;        /*
  32                                                  * Commit count mask, removing
  33                                                  * the MSBs corresponding to
  34                                                  * bits used to represent the
  35                                                  * subbuffer index.
  36                                                  */
  37         /* End of first 32 bytes cacheline */
  38
  39         /*
  40          * buffer_begin - called on buffer-switch to a new sub-buffer
  41          * @buf: the channel buffer containing the new sub-buffer
  42          */
  43         void (*buffer_begin) (struct rchan_buf *buf,
  44                         u64 tsc, unsigned int subbuf_idx);
  45         /*
  46          * buffer_end - called on buffer-switch to a new sub-buffer
  47          * @buf: the channel buffer containing the previous sub-buffer
  48          */
  49         void (*buffer_end) (struct rchan_buf *buf,
  50                         u64 tsc, unsigned int offset, unsigned int subbuf_idx);
  51         struct kref kref;       /* Channel transport reference count */
  52         unsigned int subbuf_size;
  53         unsigned int subbuf_cnt;
  54         const char *channel_name;
  55
  56         int buf_shmid;
  57 } ____cacheline_aligned;
  58
  59 struct ltt_channel_setting {
  60         unsigned int subbuf_size;
  61         unsigned int subbuf_cnt;
  62         struct kref kref;       /* Number of references to structure content */
  63         struct list_head list;
  64         unsigned int index;     /* index of channel in trace channel array */
  65         u16 free_event_id;      /* Next event ID to allocate */
  66         char name[PATH_MAX];
  67 };
  68
  69 int ltt_channels_register(const char *name);
  70 int ltt_channels_unregister(const char *name);
  71 int ltt_channels_set_default(const char *name,
  72                              unsigned int subbuf_size,
  73                              unsigned int subbuf_cnt);
  74 const char *ltt_channels_get_name_from_index(unsigned int index);
  75 int ltt_channels_get_index_from_name(const char *name);
  76 struct ltt_channel_struct *ltt_channels_trace_alloc(unsigned int *nr_channels,
  77                                                     int overwrite,
  78                                                     int active);
  79 void ltt_channels_trace_free(struct ltt_channel_struct *channels);
  80 int _ltt_channels_get_event_id(const char *channel, const char *name);
  81 int ltt_channels_get_event_id(const char *channel, const char *name);
  82
  83 #endif /* _LTT_CHANNELS_H */