linux/Documentation/trace
Linus Torvalds aa1a8ce533 New tracing features:
- The ring buffer is no longer disabled when reading the trace file.
    The trace_pipe file was made to be used for live tracing and reading
    as it acted like the normal producer/consumer. As the trace file
    would not consume the data, the easy way of handling it was to just
    disable writes to the ring buffer. This came to a surprise to the
    BPF folks who complained about lost events due to reading.
    This is no longer an issue. If someone wants to keep the old disabling
    there's a new option "pause-on-trace" that can be set.
 
  - New set_ftrace_notrace_pid file. PIDs in this file will not be traced
    by the function tracer. Similar to set_ftrace_pid, which makes the
    function tracer only trace those tasks with PIDs in the file, the
    set_ftrace_notrace_pid does the reverse.
 
  - New set_event_notrace_pid file. PIDs in this file will cause events
    not to be traced if triggered by a task with a matching PID.
    Similar to the set_event_pid file but will not be traced.
    Note, sched_waking and sched_switch events may still be trace if
    one of the tasks referenced by those events contains a PID that
    is allowed to be traced.
 
 Tracing related features:
 
  - New bootconfig option, that is attached to the initrd file.
    If bootconfig is on the command line, then the initrd file
    is searched looking for a bootconfig appended at the end.
 
  - New GPU tracepoint infrastructure to help the gfx drivers to get
    off debugfs (acked by Greg Kroah-Hartman)
 
 Other minor updates and fixes.
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Merge tag 'trace-v5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "New tracing features:

   - The ring buffer is no longer disabled when reading the trace file.

     The trace_pipe file was made to be used for live tracing and
     reading as it acted like the normal producer/consumer. As the trace
     file would not consume the data, the easy way of handling it was to
     just disable writes to the ring buffer.

     This came to a surprise to the BPF folks who complained about lost
     events due to reading. This is no longer an issue. If someone wants
     to keep the old disabling there's a new option "pause-on-trace"
     that can be set.

   - New set_ftrace_notrace_pid file. PIDs in this file will not be
     traced by the function tracer.

     Similar to set_ftrace_pid, which makes the function tracer only
     trace those tasks with PIDs in the file, the set_ftrace_notrace_pid
     does the reverse.

   - New set_event_notrace_pid file. PIDs in this file will cause events
     not to be traced if triggered by a task with a matching PID.

     Similar to the set_event_pid file but will not be traced. Note,
     sched_waking and sched_switch events may still be traced if one of
     the tasks referenced by those events contains a PID that is allowed
     to be traced.

  Tracing related features:

   - New bootconfig option, that is attached to the initrd file.

     If bootconfig is on the command line, then the initrd file is
     searched looking for a bootconfig appended at the end.

   - New GPU tracepoint infrastructure to help the gfx drivers to get
     off debugfs (acked by Greg Kroah-Hartman)

  And other minor updates and fixes"

* tag 'trace-v5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (27 commits)
  tracing: Do not allocate buffer in trace_find_next_entry() in atomic
  tracing: Add documentation on set_ftrace_notrace_pid and set_event_notrace_pid
  selftests/ftrace: Add test to test new set_event_notrace_pid file
  selftests/ftrace: Add test to test new set_ftrace_notrace_pid file
  tracing: Create set_event_notrace_pid to not trace tasks
  ftrace: Create set_ftrace_notrace_pid to not trace tasks
  ftrace: Make function trace pid filtering a bit more exact
  ftrace/kprobe: Show the maxactive number on kprobe_events
  tracing: Have the document reflect that the trace file keeps tracing enabled
  ring-buffer/tracing: Have iterator acknowledge dropped events
  tracing: Do not disable tracing when reading the trace file
  ring-buffer: Do not disable recording when there is an iterator
  ring-buffer: Make resize disable per cpu buffer instead of total buffer
  ring-buffer: Optimize rb_iter_head_event()
  ring-buffer: Do not die if rb_iter_peek() fails more than thrice
  ring-buffer: Have rb_iter_head_event() handle concurrent writer
  ring-buffer: Add page_stamp to iterator for synchronization
  ring-buffer: Rename ring_buffer_read() to read_buffer_iter_advance()
  ring-buffer: Have ring_buffer_empty() not depend on tracing stopped
  tracing: Save off entry when peeking at next entry
  ...
2020-04-05 10:36:18 -07:00
..
coresight docs: coresight: Update documentation for CoreSight to cover CTI 2020-03-21 11:32:21 +01:00
postprocess mm: move recent_rotated pages calculation to shrink_inactive_list() 2019-05-14 09:47:45 -07:00
boottime-trace.rst Documentation: tracing: Fix typos in boot-time tracing documentation 2020-01-21 18:25:16 -05:00
events-kmem.rst trace doc: convert trace/events-kmem.txt to rst format 2018-03-07 10:25:54 -07:00
events-msr.rst trace doc: convert trace/events-msr.txt to rst format 2018-03-07 10:26:06 -07:00
events-nmi.rst trace doc: convert trace/events-nmi.txt to rst format 2018-03-07 10:26:02 -07:00
events-power.rst PM: QoS: Simplify definitions of CPU latency QoS trace events 2020-02-13 11:26:39 +01:00
events.rst docs: trace: events.rst: convert some new stuff to ReST format 2020-03-10 11:46:19 -06:00
ftrace-design.rst trace doc: convert trace/ftrace-design.txt to rst format 2018-03-07 10:22:57 -07:00
ftrace-uses.rst tracing: Use CONFIG_PREEMPTION 2019-11-13 09:37:28 -05:00
ftrace.rst tracing: Add documentation on set_ftrace_notrace_pid and set_event_notrace_pid 2020-03-27 16:39:02 -04:00
function-graph-fold.vim
histogram.rst docs: tracing: Fix typos in histogram.rst 2019-05-29 15:49:01 -06:00
hwlat_detector.rst trace doc: convert trace/hwlat_detector.txt to rst fromat 2018-03-07 10:26:14 -07:00
index.rst Documentation: tracing: Add boot-time tracing document 2020-01-13 13:19:42 -05:00
intel_th.rst intel_th: Document software sinks 2019-11-14 14:48:49 +08:00
kprobetrace.rst Documentation: build warnings related to missing blank lines after explicit markups has been fixed 2020-02-05 10:30:03 -07:00
mmiotrace.rst trace doc: convert trace/mmiotrace.txt to rst format 2018-03-07 10:26:10 -07:00
ring-buffer-design.txt docs: ftrace: Fix small notation mistake 2020-01-10 10:52:47 -07:00
stm.rst stm class: SPDX-ify the documentation 2018-10-11 12:12:55 +02:00
sys-t.rst stm class: Document the MIPI SyS-T protocol usage 2018-10-11 12:12:55 +02:00
tracepoint-analysis.rst docs: Fix some broken references 2018-06-15 18:10:01 -03:00
tracepoints.rst trace doc: convert trace/tracepoints.txt to rst format 2018-03-07 10:23:23 -07:00
uprobetracer.rst tracing/probe: Add immediate parameter support 2019-08-31 12:19:39 -04:00