• Linus Torvalds's avatar
    Merge tag 'trace-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace · 9e8529af
    Linus Torvalds authored
    Pull tracing updates from Steven Rostedt:
     "Along with the usual minor fixes and clean ups there are a few major
      changes with this pull request.
       1) Multiple buffers for the ftrace facility
      This feature has been requested by many people over the last few
      years.  I even heard that Google was about to implement it themselves.
      I finally had time and cleaned up the code such that you can now
      create multiple instances of the ftrace buffer and have different
      events go to different buffers.  This way, a low frequency event will
      not be lost in the noise of a high frequency event.
      Note, currently only events can go to different buffers, the tracers
      (ie function, function_graph and the latency tracers) still can only
      be written to the main buffer.
       2) The function tracer triggers have now been extended.
      The function tracer had two triggers.  One to enable tracing when a
      function is hit, and one to disable tracing.  Now you can record a
      stack trace on a single (or many) function(s), take a snapshot of the
      buffer (copy it to the snapshot buffer), and you can enable or disable
      an event to be traced when a function is hit.
       3) A perf clock has been added.
      A "perf" clock can be chosen to be used when tracing.  This will cause
      ftrace to use the same clock as perf uses, and hopefully this will
      make it easier to interleave the perf and ftrace data for analysis."
    * tag 'trace-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (82 commits)
      tracepoints: Prevent null probe from being added
      tracing: Compare to 1 instead of zero for is_signed_type()
      tracing: Remove obsolete macro guard _TRACE_PROFILE_INIT
      ftrace: Get rid of ftrace_profile_bits
      tracing: Check return value of tracing_init_dentry()
      tracing: Get rid of unneeded key calculation in ftrace_hash_move()
      tracing: Reset ftrace_graph_filter_enabled if count is zero
      tracing: Fix off-by-one on allocating stat->pages
      kernel: tracing: Use strlcpy instead of strncpy
      tracing: Update debugfs README file
      tracing: Fix ftrace_dump()
      tracing: Rename trace_event_mutex to trace_event_sem
      tracing: Fix comment about prefix in arch_syscall_match_sym_name()
      tracing: Convert trace_destroy_fields() to static
      tracing: Move find_event_field() into trace_events.c
      tracing: Use TRACE_MAX_PRINT instead of constant
      tracing: Use pr_warn_once instead of open coded implementation
      ring-buffer: Add ring buffer startup selftest
      tracing: Bring Documentation/trace/ftrace.txt up to date
      tracing: Add "perf" trace_clock
trace_stack.c 10 KB