tracing: Introduce two additional marks for delay

A fine granulity support for delay would be very useful when profiling
VM logics, such as page allocation including page reclaim and memory
compaction with function graph.

Thus, this patch adds two additional marks with two changes.

 - An equal sign in mark selection function is removed to align code
   behavior with comments and documentation.

 - The function graph example related to delay in ftrace.txt is updated
   to cover all supported marks.

Link: http://lkml.kernel.org/r/1436626300-1679-3-git-send-email-jungseoklee85@gmail.com
Cc: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index 7ddb1e319f84d1313f9c9ca0009c9f3ae5c64ef8..072d3c4d57539344871424c28ca841311d675c91 100644 (file)
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -686,6 +686,8 @@ 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
@@ -1939,26 +1941,49 @@ 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.
 
 

diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index dfab253727dc9ea2ce674d5c0add0c9fc59c2d08..8e481a84aeea79b8b008900f3b6f5dbf3044ba7c 100644 (file)
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -496,6 +496,8 @@ static const struct trace_mark {
        char                    sym;
 } mark[] = {
        MARK(1000000000ULL      , '$'), /* 1 sec */
+       MARK(100000000ULL       , '@'), /* 100 msec */
+       MARK(10000000ULL        , '*'), /* 10 msec */
        MARK(1000000ULL         , '#'), /* 1000 usecs */
        MARK(100000ULL          , '!'), /* 100 usecs */
        MARK(10000ULL           , '+'), /* 10 usecs */
@@ -508,7 +510,7 @@ char trace_find_mark(unsigned long long d)
        int size = ARRAY_SIZE(mark);
 
        for (i = 0; i < size; i++) {
-               if (d >= mark[i].val)
+               if (d > mark[i].val)
                        break;
        }