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| author | Tom Zanussi <tom.zanussi@linux.intel.com> | 2016-03-03 18:54:44 (GMT) |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2016-04-19 16:16:33 (GMT) |
| commit | 76a3b0c8ac344e1d0f436160cbb59b670b086947 (patch) | |
| tree | 9a4c5943aae4e08208a0c77a6c457f1ca3650542 /kernel/trace/trace.c | |
| parent | f2606835d70d2a2e6a134f01821da8149e124796 (diff) | |
| download | linux-76a3b0c8ac344e1d0f436160cbb59b670b086947.tar.xz | |
tracing: Add hist trigger support for compound keys
Allow users to specify multiple trace event fields to use in keys by
allowing multiple fields in the 'keys=' keyword. With this addition,
any unique combination of any of the fields named in the 'keys'
keyword will result in a new entry being added to the hash table.
Link: http://lkml.kernel.org/r/0cfa24e6ac3b0dcece7737d94aa1f322ae3afc4b.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 | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index bb62f54..7a4c4dc 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3833,7 +3833,7 @@ static const char readme_msg[] = "\t Filters can be ignored when removing a trigger.\n" #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 Format: hist:keys=<field1[,field2,...]>\n" "\t [:values=<field1[,field2,...]>]\n" "\t [:size=#entries]\n" "\t [if <filter>]\n\n" @@ -3841,9 +3841,11 @@ static const char readme_msg[] = "\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 can be any field. Compound keys consisting of up to two\n" + "\t fields can be specified by the 'keys' keyword. Values must\n" + "\t correspond to numeric fields. The 'size' parameter can be\n" + "\t used to specify more or fewer than the default 2048 entries\n" + "\t 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 |