diff options
| author | Tom Zanussi <tom.zanussi@linux.intel.com> | 2018-01-15 20:52:03 -0600 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-03-10 16:06:01 -0500 |
| commit | 8b7622bf94a44b3f912e6492bf500e86171300b8 (patch) | |
| tree | 525d8fb6088788683db798b3e07f42ec1f7f6e05 /Documentation/trace | |
| parent | ec5ce0987541087dbea5af346bdb85eb04b0f0a2 (diff) | |
tracing: Add cpu field for hist triggers
A common key to use in a histogram is the cpuid - add a new cpu
'synthetic' field named 'cpu' for that purpose.
Link: http://lkml.kernel.org/r/89537645bfc957e0d76e2cacf5f0ada88691a6cc.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'Documentation/trace')
| -rw-r--r-- | Documentation/trace/histogram.txt | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/Documentation/trace/histogram.txt b/Documentation/trace/histogram.txt index 25c94730d3fe..be612ca79455 100644 --- a/Documentation/trace/histogram.txt +++ b/Documentation/trace/histogram.txt @@ -172,6 +172,21 @@ The examples below provide a more concrete illustration of the concepts and typical usage patterns discussed above. + 'special' event fields + ------------------------ + + There are a number of 'special event fields' available for use as + keys or values in a hist trigger. These look like and behave as if + they were actual event fields, but aren't really part of the event's + field definition or format file. They are however available for any + event, and can be used anywhere an actual event field could be. + They are: + + common_timestamp u64 - timestamp (from ring buffer) associated + with the event, in nanoseconds. May be + modified by .usecs to have timestamps + interpreted as microseconds. + cpu int - the cpu on which the event occurred. 6.2 'hist' trigger examples --------------------------- |