diff options
| author | Tom Zanussi <tom.zanussi@linux.intel.com> | 2016-03-03 12:54:43 -0600 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2016-04-19 12:16:23 -0400 |
| commit | f2606835d70d2a2e6a134f01821da8149e124796 (patch) | |
| tree | f8b946af11b5f348080d5ad0c51a438ac2a5fdef /kernel/trace/trace.c | |
| parent | 7ef224d1d0e3a1ade02d02c01ce1dcffb736d2c3 (diff) | |
tracing: Add hist trigger support for multiple values ('vals=' param)
Allow users to specify trace event fields to use in aggregated sums
via a new 'vals=' keyword. Before this addition, the only aggregated
sum supported was the implied value 'hitcount'. With this addition,
'hitcount' is also supported as an explicit value field, as is any
numeric trace event field.
This expands the hist trigger syntax from this:
# echo hist:keys=xxx [ if filter] > event/trigger
to this:
# echo hist:keys=xxx:vals=yyy [ if filter] > event/trigger
Link: http://lkml.kernel.org/r/2a5d1adb5ba6c65d7bb2148e379f2fed47f29a68.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 6cf8fd03b028..bb62f54c5480 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3834,14 +3834,16 @@ static const char readme_msg[] = #ifdef CONFIG_HIST_TRIGGERS " hist trigger\t- If set, event hits are aggregated into a hash table\n" "\t Format: hist:keys=<field1>\n" + "\t [:values=<field1[,field2,...]>]\n" "\t [:size=#entries]\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 named, and the value of a sum called\n" - "\t 'hitcount' is incremented. Keys correspond to fields in the\n" - "\t event's format description. Keys can be any field. The\n" - "\t 'size' parameter can be used to specify more or fewer than\n" - "\t the default 2048 entries for the hashtable size.\n\n" + "\t table using the key(s) and value(s) named, and the value of a\n" + "\t sum called 'hitcount' is incremented. Keys and values\n" + "\t correspond to fields in the event's format description. Keys\n" + "\t can be any field. Values must correspond to numeric fields.\n" + "\t The 'size' parameter can be used to specify more or fewer\n" + "\t than the default 2048 entries for the hashtable size.\n\n" "\t Reading the 'hist' file for the event will dump the hash\n" "\t table in its entirety to stdout." #endif |