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Diffstat (limited to 'docs/users_guide/eventlog-formats.rst')
| -rw-r--r-- | docs/users_guide/eventlog-formats.rst | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/docs/users_guide/eventlog-formats.rst b/docs/users_guide/eventlog-formats.rst index 27bd37cd3f..a3ed47fc3c 100644 --- a/docs/users_guide/eventlog-formats.rst +++ b/docs/users_guide/eventlog-formats.rst @@ -134,3 +134,33 @@ A variable-length event encoding a heap sample broken down by, * ``Word8``: Profile ID * ``Word64``: heap residency in bytes * ``String``: type or closure description, or module name + +.. _time-profiler-events: + +Time profiler event log output +------------------------------ + +The time profiling mode enabled by ``-p`` also emits sample events to the eventlog. +At the start of profiling the tick interval is emitted to the eventlog and then +on each tick the current cost centre stack is emitted. Together these enable +a user to construct an approximate track of the executation of their program. + +Profile begin event +^^^^^^^^^^^^^^^^^^^ + + * ``EVENT_PROF_BEGIN`` + + * ``Word64``: Tick interval, in nanoseconds + + +Tick sample event +^^^^^^^^^^^^^^^^^^ + +A variable-length packet encoding a profile sample. + +* ``EVENT_PROF_SAMPLE_COST_CENTRE`` + + * ``Word32``: Capability + * ``Word64``: Current profiling tick + * ``Word8``: stack depth + * ``Word32[]``: cost centre stack starting with inner-most (cost centre numbers) |