[PATCH v7 03/16] tracing: Add hist trigger handler.action documentation to README

Tom Zanussi
2018-11-14T20:18:26Z

From: Tom Zanussi <tom.zanussi@linux.intel.com>

Add abbreviated documentation for handlers and actions to README.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
---
kernel/trace/trace.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index ff1c4b20cd0a..998955dcc3ca 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4686,6 +4686,7 @@ static const char readme_msg[] =
"\t [:size=#entries]\n"
"\t [:pause][:continue][:clear]\n"
"\t [:name=histname1]\n"
+ "\t [:<handler>.<action>]\n"
"\t [if <filter>]\n\n"
"\t When a matching event is hit, an entry is added to a hash\n"
"\t table using the key(s) and value(s) named, and the value of a\n"
@@ -4727,7 +4728,16 @@ static const char readme_msg[] =
"\t The enable_hist and disable_hist triggers can be used to\n"
"\t have one event conditionally start and stop another event's\n"
"\t already-attached hist trigger. The syntax is analagous to\n"
- "\t the enable_event and disable_event triggers.\n"
+ "\t the enable_event and disable_event triggers.\n\n"
+ "\t Hist trigger handlers and actions are executed whenever a\n"
+ "\t a histogram entry is added or updated. They take the form:\n\n"
+ "\t <handler>.<action>\n\n"
+ "\t The available handlers are:\n\n"
+ "\t onmatch(matching.event) - invoke on addition or update\n"
+ "\t onmax(var) - invoke if var exceeds current max\n\n"
+ "\t The available actions are:\n\n"
+ "\t <synthetic_event>(param list) - generate synthetic event\n"
+ "\t save(field,...) - save current event fields\n"
#endif
;

--
2.14.1