From e86ae9baacfa9efe957df4fc037f079772636d76 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:47 -0600 Subject: tracing: Add hist trigger support for clearing a trace Allow users to append 'clear' to an existing trigger in order to have the hash table cleared. This expands the hist trigger syntax from this: # echo hist:keys=xxx:vals=yyy:sort=zzz.descending:pause/cont \ [ if filter] >> event/trigger to this: # echo hist:keys=xxx:vals=yyy:sort=zzz.descending:pause/cont/clear \ [ if filter] >> event/trigger Link: http://lkml.kernel.org/r/ae15dd0d9b2f7af07a37c1ff682063e2dbcdf160.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'kernel/trace/trace.c') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7d5c63dd410a..4097cd3763f7 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3837,7 +3837,7 @@ static const char readme_msg[] = "\t [:values=]\n" "\t [:sort=]\n" "\t [:size=#entries]\n" - "\t [:pause][:continue]\n" + "\t [:pause][:continue][:clear]\n" "\t [if ]\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" @@ -3857,6 +3857,9 @@ static const char readme_msg[] = "\t trigger or to start a hist trigger but not log any events\n" "\t until told to do so. 'continue' can be used to start or\n" "\t restart a paused hist trigger.\n\n" + "\t The 'clear' parameter will clear the contents of a running\n" + "\t hist trigger and leave its current paused/active state\n" + "\t unchanged.\n\n" #endif ; -- cgit v1.2.3