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authorLinus Torvalds <torvalds@linux-foundation.org>2015-09-08 14:04:14 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-09-08 14:04:14 -0700
commit59a47fff0217592e248556a7ab436d5c17365962 (patch)
treec0c115f75d494358c9921e8fc635fac351c13b9c /Documentation
parent425afcff13a4bea2a3cf6f395cbc66fc158852be (diff)
parentb7dc42fd79390c074e2bff3b172b585d5c2d80c2 (diff)
downloadlinux-59a47fff0217592e248556a7ab436d5c17365962.tar.gz
Merge tag 'trace-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing update from Steven Rostedt:
 "Mostly this is just clean ups and micro optimizations.

  The changes with more meat are:

   - Allowing the trace event filters to filter on CPU number and
     process ids

   - Two new markers for trace output latency were added (10 and 100
     msec latencies)

   - Have tracing_thresh filter function profiling time

  I also worked on modifying the ring buffer code for some future work,
  and moved the adding of the timestamp around.  One of my changes
  caused a regression, and since other changes were built on top of it
  and already tested, I had to operate a revert of that change.  Instead
  of rebasing, this change set has the code that caused a regression as
  well as the code to revert that change without touching the other
  changes that were made on top of it"

* tag 'trace-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ring-buffer: Revert "ring-buffer: Get timestamp after event is allocated"
  tracing: Don't make assumptions about length of string on task rename
  tracing: Allow triggers to filter for CPU ids and process names
  ftrace: Format MCOUNT_ADDR address as type unsigned long
  tracing: Introduce two additional marks for delay
  ftrace: Fix function_graph duration spacing with 7-digits
  ftrace: add tracing_thresh to function profile
  tracing: Clean up stack tracing and fix fentry updates
  ring-buffer: Reorganize function locations
  ring-buffer: Make sure event has enough room for extend and padding
  ring-buffer: Get timestamp after event is allocated
  ring-buffer: Move the adding of the extended timestamp out of line
  ring-buffer: Add event descriptor to simplify passing data
  ftrace: correct the counter increment for trace_buffer data
  tracing: Fix for non-continuous cpu ids
  tracing: Prefer kcalloc over kzalloc with multiply
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/trace/ftrace.txt51
1 files changed, 38 insertions, 13 deletions
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index 87bb4aa6a6b9..ef621d34ba5b 100644
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -691,6 +691,8 @@ The above is mostly meaningful for kernel developers.
 	 The marks are determined by the difference between this
 	 current trace and the next trace.
 	  '$' - greater than 1 second
+	  '@' - greater than 100 milisecond
+	  '*' - greater than 10 milisecond
 	  '#' - greater than 1000 microsecond
 	  '!' - greater than 100 microsecond
 	  '+' - greater than 10 microsecond
@@ -1944,26 +1946,49 @@ want, depending on your needs.
 
   ie:
 
-  0)               |    up_write() {
-  0)   0.646 us    |      _spin_lock_irqsave();
-  0)   0.684 us    |      _spin_unlock_irqrestore();
-  0)   3.123 us    |    }
-  0)   0.548 us    |    fput();
-  0) + 58.628 us   |  }
+  3) # 1837.709 us |          } /* __switch_to */
+  3)               |          finish_task_switch() {
+  3)   0.313 us    |            _raw_spin_unlock_irq();
+  3)   3.177 us    |          }
+  3) # 1889.063 us |        } /* __schedule */
+  3) ! 140.417 us  |      } /* __schedule */
+  3) # 2034.948 us |    } /* schedule */
+  3) * 33998.59 us |  } /* schedule_preempt_disabled */
 
   [...]
 
-  0)               |      putname() {
-  0)               |        kmem_cache_free() {
-  0)   0.518 us    |          __phys_addr();
-  0)   1.757 us    |        }
-  0)   2.861 us    |      }
-  0) ! 115.305 us  |    }
-  0) ! 116.402 us  |  }
+  1)   0.260 us    |              msecs_to_jiffies();
+  1)   0.313 us    |              __rcu_read_unlock();
+  1) + 61.770 us   |            }
+  1) + 64.479 us   |          }
+  1)   0.313 us    |          rcu_bh_qs();
+  1)   0.313 us    |          __local_bh_enable();
+  1) ! 217.240 us  |        }
+  1)   0.365 us    |        idle_cpu();
+  1)               |        rcu_irq_exit() {
+  1)   0.417 us    |          rcu_eqs_enter_common.isra.47();
+  1)   3.125 us    |        }
+  1) ! 227.812 us  |      }
+  1) ! 457.395 us  |    }
+  1) @ 119760.2 us |  }
+
+  [...]
+
+  2)               |    handle_IPI() {
+  1)   6.979 us    |                  }
+  2)   0.417 us    |      scheduler_ipi();
+  1)   9.791 us    |                }
+  1) + 12.917 us   |              }
+  2)   3.490 us    |    }
+  1) + 15.729 us   |            }
+  1) + 18.542 us   |          }
+  2) $ 3594274 us  |  }
 
   + means that the function exceeded 10 usecs.
   ! means that the function exceeded 100 usecs.
   # means that the function exceeded 1000 usecs.
+  * means that the function exceeded 10 msecs.
+  @ means that the function exceeded 100 msecs.
   $ means that the function exceeded 1 sec.