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Commit 5eb6eed7 authored by Linus Torvalds's avatar Linus Torvalds
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Merge tag 'trace-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 

Pull tracing updates from Steven Rostedt:
 "One new feature was added to ftrace, which is the trace_marker now
  supports triggers. For example:

    # cd /sys/kernel/debug/tracing
    # echo 'snapshot' > events/ftrace/print/trigger
    # echo 'cause snapshot' > trace_marker

  The rest of the changes are various clean ups and also one stable fix
  that was added late in the cycle"

* tag 'trace-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (21 commits)
  tracing: Use match_string() instead of open coding it in trace_set_options()
  branch-check: fix long->int truncation when profiling branches
  ring-buffer: Fix typo in comment
  ring-buffer: Fix a bunch of typos in comments
  tracing/selftest: Add test to test simple snapshot trigger for trace_marker
  tracing/selftest: Add test to test hist trigger between kernel event and trace_marker
  tracing/selftest: Add selftests to test trace_marker histogram triggers
  ftrace/selftest: Fix reset_trigger() to handle triggers with filters
  ftrace/selftest: Have the reset_trigger code be a bit more careful
  tracing: Document trace_marker triggers
  tracing: Allow histogram triggers to access ftrace internal events
  tracing: Prevent further users of zero size static arrays in trace events
  tracing: Have zero size length in filter logic be full string
  tracing: Add trigger file for trace_markers tracefs/ftrace/print
  tracing: Do not show filter file for ftrace internal events
  tracing: Add brackets in ftrace event dynamic arrays
  tracing: Have event_trace_init() called by trace_init_tracefs()
  tracing: Add __find_event_file() to find event files without restrictions
  tracing: Do not reference event data in post call triggers
  tracepoints: Fix the descriptions of tracepoint_probe_register{_prio}
  ...
parents 8b5c6a3a 591a033d

Documentation/trace/events.rst

+5 −1
Original line number Diff line number Diff line
@@ -338,10 +338,14 @@ used for conditionally invoking triggers. 


The syntax for event triggers is roughly based on the syntax for

set_ftrace_filter 'ftrace filter commands' (see the 'Filter commands'

section of Documentation/trace/ftrace.txt), but there are major

section of Documentation/trace/ftrace.rst), but there are major

differences and the implementation isn't currently tied to it in any

way, so beware about making generalizations between the two.



Note: Writing into trace_marker (See Documentation/trace/ftrace.rst)

     can also enable triggers that are written into

     /sys/kernel/tracing/events/ftrace/print/trigger



6.1 Expression syntax

---------------------

Documentation/trace/ftrace.rst

+5 −0
Original line number Diff line number Diff line
@@ -512,6 +512,11 @@ of ftrace. Here is a list of some of the key files: 


		trace_fd = open("trace_marker", WR_ONLY);



	Note: Writing into the trace_marker file can also initiate triggers

	      that are written into /sys/kernel/tracing/events/ftrace/print/trigger

	      See "Event triggers" in Documentation/trace/events.rst and an

              example in Documentation/trace/histogram.rst (Section 3.)



  trace_marker_raw:



	This is similar to trace_marker above, but is meant for for binary data