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authorTom Zanussi <tom.zanussi@linux.intel.com>2019-02-13 17:42:48 -0600
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2019-02-20 13:51:07 -0500
commitdff81f559285b5c6df287eb231a9d6b02057ef8b (patch)
treea244223ef1235c75508ed624ea1a7fe718ef9f22 /kernel/trace/trace.c
parentfd451a3d9291815d13f3f1ce60537b7f19616b23 (diff)
downloadlinux-dff81f559285b5c6df287eb231a9d6b02057ef8b.tar.bz2
tracing: Add hist trigger onchange() handler
Add support for a hist:onchange($var) handler, similar to the onmax() handler but triggering whenever there's any change in $var, not just a max. Link: http://lkml.kernel.org/r/dfbc7e4ada242603e9ec3f049b5ad076a07dfd03.1550100284.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 'kernel/trace/trace.c')
-rw-r--r--kernel/trace/trace.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index dd60c14a0fb0..be6779f963c6 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4915,7 +4915,8 @@ static const char readme_msg[] =
"\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 onmax(var) - invoke if var exceeds current max\n"
+ "\t onchange(var) - invoke action if var changes\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"