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authorTom Zanussi <tom.zanussi@linux.intel.com>2019-02-13 17:42:46 -0600
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2019-02-20 13:51:07 -0500
commita3785b7eca8fd45c7c39f2ddfcd67368af30c1b4 (patch)
tree7090f2e113486f00c6f26da049ce0e581eceb162 /kernel/trace/trace.c
parenta35873a0993b4d38b40871f10fa4356c088c7140 (diff)
tracing: Add hist trigger snapshot() action
Add support for hist:handlerXXX($var).snapshot(), which will take a snapshot of the current trace buffer whenever handlerXXX is hit. As a first user, this also adds snapshot() action support for the onmax() handler i.e. hist:onmax($var).snapshot(). Also, the hist trigger key printing is moved into a separate function so the snapshot() action can print a histogram key outside the histogram display - add and use hist_trigger_print_key() for that purpose. Link: http://lkml.kernel.org/r/2f1a952c0dcd8aca8702ce81269581a692396d45.1550100284.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, 3 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 9f4d56f74b46..dd60c14a0fb0 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4919,6 +4919,9 @@ static const char readme_msg[] =
"\t The available actions are:\n\n"
"\t <synthetic_event>(param list) - generate synthetic event\n"
"\t save(field,...) - save current event fields\n"
+#ifdef CONFIG_TRACER_SNAPSHOT
+ "\t snapshot() - snapshot the trace buffer\n"
+#endif
#endif
;