1. 15 Mar, 2013 28 commits
  2. 14 Mar, 2013 1 commit
  3. 13 Mar, 2013 7 commits
  4. 11 Mar, 2013 1 commit
  5. 08 Mar, 2013 1 commit
  6. 07 Mar, 2013 2 commits
    • Steven Rostedt (Red Hat)'s avatar
      tracing: Do not return EINVAL in snapshot when not allocated · c9960e48
      Steven Rostedt (Red Hat) authored
      To use the tracing snapshot feature, writing a '1' into the snapshot
      file causes the snapshot buffer to be allocated if it has not already
      been allocated and dose a 'swap' with the main buffer, so that the
      snapshot now contains what was in the main buffer, and the main buffer
      now writes to what was the snapshot buffer.
      
      To free the snapshot buffer, a '0' is written into the snapshot file.
      
      To clear the snapshot buffer, any number but a '0' or '1' is written
      into the snapshot file. But if the file is not allocated it returns
      -EINVAL error code. This is rather pointless. It is better just to
      do nothing and return success.
      Acked-by: default avatarHiraku Toyooka <hiraku.toyooka.gu@hitachi.com>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      c9960e48
    • Steven Rostedt (Red Hat)'s avatar
      tracing: Add help of snapshot feature when snapshot is empty · d8741e2e
      Steven Rostedt (Red Hat) authored
      When cat'ing the snapshot file, instead of showing an empty trace
      header like the trace file does, show how to use the snapshot
      feature.
      
      Also, this is a good place to show if the snapshot has been allocated
      or not. Users may want to "pre allocate" the snapshot to have a fast
      "swap" of the current buffer. Otherwise, a swap would be slow and might
      fail as it would need to allocate the snapshot buffer, and that might
      fail under tight memory constraints.
      
      Here's what it looked like before:
      
       # tracer: nop
       #
       # entries-in-buffer/entries-written: 0/0   #P:4
       #
       #                              _-----=> irqs-off
       #                             / _----=> need-resched
       #                            | / _---=> hardirq/softirq
       #                            || / _--=> preempt-depth
       #                            ||| /     delay
       #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
       #              | |       |   ||||       |         |
      
      Here's what it looks like now:
      
       # tracer: nop
       #
       #
       # * Snapshot is freed *
       #
       # Snapshot commands:
       # echo 0 > snapshot : Clears and frees snapshot buffer
       # echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.
       #                      Takes a snapshot of the main buffer.
       # echo 2 > snapshot : Clears snapshot buffer (but does not allocate)
       #                      (Doesn't have to be '2' works with any number that
       #                       is not a '0' or '1')
      Acked-by: default avatarHiraku Toyooka <hiraku.toyooka.gu@hitachi.com>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      d8741e2e