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Release 4.12 include/linux/ring_buffer.h

Directory: include/linux


#include <linux/kmemcheck.h>
#include <linux/mm.h>
#include <linux/seq_file.h>
#include <linux/poll.h>

struct ring_buffer;
struct ring_buffer_iter;

 * Don't refer to this struct directly, use functions below.

struct ring_buffer_event {

u32		type_len:5, time_delta:27;

u32		array[];

 * enum ring_buffer_type - internal ring buffer types
 * @RINGBUF_TYPE_PADDING:       Left over page padding or discarded event
 *                               If time_delta is 0:
 *                                array is ignored
 *                                size is variable depending on how much
 *                                padding is needed
 *                               If time_delta is non zero:
 *                                array[0] holds the actual length
 *                                size = 4 + length (bytes)
 * @RINGBUF_TYPE_TIME_EXTEND:   Extend the time delta
 *                               array[0] = time delta (28 .. 59)
 *                               size = 8 bytes
 * @RINGBUF_TYPE_TIME_STAMP:    Sync time stamp with external clock
 *                               array[0]    = tv_nsec
 *                               array[1..2] = tv_sec
 *                               size = 16 bytes
 *                              Data record
 *                               If type_len is zero:
 *                                array[0] holds the actual length
 *                                array[1..(length+3)/4] holds data
 *                                size = 4 + length (bytes)
 *                               else
 *                                length = type_len << 2
 *                                array[0..(length+3)/4-1] holds data
 *                                size = 4 + length (bytes)

enum ring_buffer_type {
	/* FIXME: RINGBUF_TYPE_TIME_STAMP not implemented */

unsigned ring_buffer_event_length(struct ring_buffer_event *event);
void *ring_buffer_event_data(struct ring_buffer_event *event);

 * ring_buffer_discard_commit will remove an event that has not
 *   ben committed yet. If this is used, then ring_buffer_unlock_commit
 *   must not be called on the discarded event. This function
 *   will try to remove the event from the ring buffer completely
 *   if another event has not been written after it.
 * Example use:
 *  if (some_condition)
 *    ring_buffer_discard_commit(buffer, event);
 *  else
 *    ring_buffer_unlock_commit(buffer, event);
void ring_buffer_discard_commit(struct ring_buffer *buffer,
				struct ring_buffer_event *event);

 * size is in bytes for each per CPU buffer.
struct ring_buffer *
__ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *key);

 * Because the ring buffer is generic, if other users of the ring buffer get
 * traced by ftrace, it can produce lockdep warnings. We need to keep each
 * ring buffer's lock class separate.

#define ring_buffer_alloc(size, flags)			\
({                                                      \
        static struct lock_class_key __key;             \
        __ring_buffer_alloc((size), (flags), &__key);   \

int ring_buffer_wait(struct ring_buffer *buffer, int cpu, bool full);
int ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu,
			  struct file *filp, poll_table *poll_table);


void ring_buffer_free(struct ring_buffer *buffer);

int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size, int cpu);

void ring_buffer_change_overwrite(struct ring_buffer *buffer, int val);

struct ring_buffer_event *ring_buffer_lock_reserve(struct ring_buffer *buffer,
						   unsigned long length);
int ring_buffer_unlock_commit(struct ring_buffer *buffer,
			      struct ring_buffer_event *event);
int ring_buffer_write(struct ring_buffer *buffer,
		      unsigned long length, void *data);

struct ring_buffer_event *
ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts,
		 unsigned long *lost_events);
struct ring_buffer_event *
ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts,
		    unsigned long *lost_events);

struct ring_buffer_iter *
ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu);
void ring_buffer_read_prepare_sync(void);
void ring_buffer_read_start(struct ring_buffer_iter *iter);
void ring_buffer_read_finish(struct ring_buffer_iter *iter);

struct ring_buffer_event *
ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts);
struct ring_buffer_event *
ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts);
void ring_buffer_iter_reset(struct ring_buffer_iter *iter);
int ring_buffer_iter_empty(struct ring_buffer_iter *iter);

unsigned long ring_buffer_size(struct ring_buffer *buffer, int cpu);

void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu);
void ring_buffer_reset(struct ring_buffer *buffer);

int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
			 struct ring_buffer *buffer_b, int cpu);

static inline int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, struct ring_buffer *buffer_b, int cpu) { return -ENODEV; }


Steven Rostedt24100.00%1100.00%

#endif bool ring_buffer_empty(struct ring_buffer *buffer); bool ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu); void ring_buffer_record_disable(struct ring_buffer *buffer); void ring_buffer_record_enable(struct ring_buffer *buffer); void ring_buffer_record_off(struct ring_buffer *buffer); void ring_buffer_record_on(struct ring_buffer *buffer); int ring_buffer_record_is_on(struct ring_buffer *buffer); void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu); void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu); u64 ring_buffer_oldest_event_ts(struct ring_buffer *buffer, int cpu); unsigned long ring_buffer_bytes_cpu(struct ring_buffer *buffer, int cpu); unsigned long ring_buffer_entries(struct ring_buffer *buffer); unsigned long ring_buffer_overruns(struct ring_buffer *buffer); unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu); unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu); unsigned long ring_buffer_commit_overrun_cpu(struct ring_buffer *buffer, int cpu); unsigned long ring_buffer_dropped_events_cpu(struct ring_buffer *buffer, int cpu); unsigned long ring_buffer_read_events_cpu(struct ring_buffer *buffer, int cpu); u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu); void ring_buffer_normalize_time_stamp(struct ring_buffer *buffer, int cpu, u64 *ts); void ring_buffer_set_clock(struct ring_buffer *buffer, u64 (*clock)(void)); size_t ring_buffer_page_len(void *page); void *ring_buffer_alloc_read_page(struct ring_buffer *buffer, int cpu); void ring_buffer_free_read_page(struct ring_buffer *buffer, int cpu, void *data); int ring_buffer_read_page(struct ring_buffer *buffer, void **data_page, size_t len, int cpu, int full); struct trace_seq; int ring_buffer_print_entry_header(struct trace_seq *s); int ring_buffer_print_page_header(struct trace_seq *s); enum ring_buffer_flags { RB_FL_OVERWRITE = 1 << 0, }; #ifdef CONFIG_RING_BUFFER int trace_rb_cpu_prepare(unsigned int cpu, struct hlist_node *node); #else #define trace_rb_cpu_prepare NULL #endif #endif /* _LINUX_RING_BUFFER_H */

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Steven Rostedt66079.14%1448.28%
Vaibhav Nagarnaik394.68%310.34%
Robert Richter263.12%13.45%
Sebastian Andrzej Siewior242.88%13.45%
Peter Zijlstra172.04%13.45%
David S. Miller161.92%13.45%
Vegard Nossum131.56%13.45%
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Yaowei Bai20.24%13.45%
Wenji Huang10.12%13.45%
Yoshihiro Yunomae10.12%13.45%
Directory: include/linux
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