ltt-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  * Dual LGPL v2.1/GPL v2 license.
  10  */
  11
  12 #include <linux/limits.h>
  13 #include <linux/kref.h>
  14 #include <linux/list.h>
  15 #include <linux/timer.h>
  16 #include <linux/ltt-core.h>
  17
  18 #define EVENTS_PER_CHANNEL              65536
  19
  20 #define LTT_READ_TIMER_INTERVAL         10000 /* us */
  21
  22 /*
  23  * Forward declaration of locking-specific per-cpu buffer structure.
  24  */
  25 struct ltt_trace;
  26 struct ltt_serialize_closure;
  27 struct ltt_probe_private_data;
  28
  29 /* Serialization callback '%k' */
  30 typedef size_t (*ltt_serialize_cb)(struct ltt_chanbuf *buf, size_t buf_offset,
  31                                    struct ltt_serialize_closure *closure,
  32                                    void *serialize_private,
  33                                    unsigned int stack_pos_ctx,
  34                                    int *largest_align,
  35                                    const char *fmt, va_list *args);
  36
  37 struct ltt_probe_private_data {
  38         struct ltt_trace *trace;        /*
  39                                          * Target trace, for metadata
  40                                          * or statedump.
  41                                          */
  42         ltt_serialize_cb serializer;    /*
  43                                          * Serialization function override.
  44                                          */
  45         void *serialize_private;        /*
  46                                          * Private data for serialization
  47                                          * functions.
  48                                          */
  49 };
  50
  51 struct ltt_channel_setting {
  52         unsigned int sb_size;
  53         unsigned int n_sb;
  54         int overwrite;
  55         unsigned long switch_timer_interval;
  56         unsigned long read_timer_interval;
  57         struct kref kref;       /* Number of references to structure content */
  58         struct list_head list;
  59         unsigned int index;     /* index of channel in trace channel array */
  60         u16 free_event_id;      /* Next event ID to allocate */
  61         char name[PATH_MAX];
  62 };
  63
  64 int ltt_channels_register(const char *name);
  65 int ltt_channels_unregister(const char *name, int compacting);
  66 int ltt_channels_set_default(const char *name,
  67                              unsigned int subbuf_size,
  68                              unsigned int subbuf_cnt);
  69 const char *ltt_channels_get_name_from_index(unsigned int index);
  70 int ltt_channels_get_index_from_name(const char *name);
  71 int ltt_channels_trace_ref(void);
  72 struct ltt_chan *ltt_channels_trace_alloc(unsigned int *nr_channels,
  73                                           int overwrite, int active);
  74 void ltt_channels_trace_free(struct ltt_chan *channels,
  75                              unsigned int nr_channels);
  76 void ltt_channels_trace_set_timer(struct ltt_channel_setting *chan,
  77                                   unsigned long interval);
  78
  79 int _ltt_channels_get_event_id(const char *channel, const char *name);
  80 int ltt_channels_get_event_id(const char *channel, const char *name);
  81 void _ltt_channels_reset_event_ids(void);
  82
  83 #endif /* _LTT_CHANNELS_H */