libtracefs 1.8
Changes since libtracefs 1.7
New APIs:
- tracefs_follow_event_clear() and tracefs_follow_missed_events_clear()
API to clean up followers if the tracefs instance is going to be used
for other iterations
- tracefs_instance_file_write_number()
A simple helper function to make it easier to write numbers into the
tracefs files. It does the conversion from number to string, as the
files expect strings and not numbers.
- Add API to work with kbuffer, which gives more control to the application
and speeds it up:
tracefs_cpu_read_buf()
tracefs_cpu_buffered_read_buf()
tracefs_cpu_flush_buf()
- tracefs_instance_get_buffer_percent() and tracefs_instance_set_buffer_percent()
Modify the buffer_percent file that allows readers to block until the buffer
is filled to a given percent. This keeps the reader from causing events that
will add noise to the trace.
- tracefs_instance_clear()
Helper to clear the contents of the current trace instance.
- tep_get_sub_buffer_data_size()
Helper to retrieve the current sub-buffer data size. The Linux kernel tracing
ring buffer is broken up into smaller sub-buffers. This returns the size of
the data portion of those sub-buffers (does not include the sub-buffer meta
data).
- tracefs_load_headers()
API to just load the information about the sub-buffers and nothing more.
- API to extract tracing ring buffer statistics
tracefs_instance_get_stat()
tracefs_instance_put_stat()
tracefs_buffer_stat_entries()
tracefs_buffer_stat_overrun()
tracefs_buffer_stat_commit_overrun()
tracefs_buffer_stat_bytes()
tracefs_buffer_stat_event_timestamp()
tracefs_buffer_stat_timestamp()
tracefs_buffer_stat_dropped_events
- tracefs_instance_set_subbuf_size() and tracefs_instance_get_subbuf_size()
API to modify the sub-buffers size of the tracing ring buffer.
- Added TIMESTAMP_DELTA and TIMESTAMP_DELTA_USECS to tracefs_sql() as a shortcut
for (end.TIMESTAMP - start.TIMESTAMP) and (end.TIMESTAMP_USECS - start.TIMESTAMP_USECS)
respectively
- Add PID filtering API:
tracefs_filter_pid_function()
tracefs_filter_pid_events()
tracefs_filter_pid_function_clear()
tracefs_filter_pid_events_clear()
- Added tracefs_cpu_snapshot_open() to read the raw data of snapshot buffers
- Added snapshot functions:
tracefs_snapshot_snap()
tracefs_snapshot_clear()
tracefs_snapshot_free()
- Added ring buffer memory mapping APIs
tracefs_cpu_open_mapped()
tracefs_cpu_is_mapped()
tracefs_mapped_is_supported()
tracefs_cpu_map()
tracefs_cpu_unmap()
Note, as of Linux version 6.8, the memory mapping is not supported in the
Linux kernel. Theses APIs will simply not map the ring buffer. And it
will not even map when the kernel is supported as it is currently hard coded
to fail, unless it is built with "make EXTRA_CFLAGS=-DFORCE_MMAP_ENABLE"
But applications can start using these APIs if it is reading the ring buffer
and processing it directly.
Updates:
- Increase pipe max size to max value when using splice.
- Clear "max_graph_depth" on tracefs_instance_reset()
- Add missing headers to syscall() and SYS_* defines
- Add dependency fixes to meson build
- Fix some documentation / man page issues
- Fix memory leaks
- Fix cscope rule
- Fix issues in unit tests
- Added many more unit tests
libtracefs: version 1.8
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2 files changed
