leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

tracing: Add hist trigger support for compound keys

Browse Source 
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>
This commit is contained in:
Tom Zanussi 2016-03-03 12:54:44 -06:00 committed by Steven Rostedt
parent f2606835d7
commit 76a3b0c8ac
2 changed files with 36 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
kernel/trace/trace.c
View File

@ -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

41
kernel/trace/trace_events_hist.c
View File

@ -32,6 +32,7 @@ struct hist_field {
unsigned long flags;
hist_field_fn_t fn;
unsigned int size;
unsigned int offset;
};
static u64 hist_field_counter(struct hist_field *field, void *event)
@ -73,8 +74,7 @@ DEFINE_HIST_FIELD_FN(u8);
for ((i) = (hist_data)->n_vals; (i) < (hist_data)->n_fields; (i)++)
#define HITCOUNT_IDX 0
#define HIST_KEY_MAX 1
#define HIST_KEY_SIZE_MAX MAX_FILTER_STR_VAL
#define HIST_KEY_SIZE_MAX (MAX_FILTER_STR_VAL + sizeof(u64))
enum hist_field_flags {
HIST_FIELD_FL_HITCOUNT = 1,
@ -351,6 +351,7 @@ static int create_val_fields(struct hist_trigger_data *hist_data,
static int create_key_field(struct hist_trigger_data *hist_data,
unsigned int key_idx,
unsigned int key_offset,
struct trace_event_file *file,
char *field_str)
{
@ -380,7 +381,8 @@ static int create_key_field(struct hist_trigger_data *hist_data,
key_size = ALIGN(key_size, sizeof(u64));
hist_data->fields[key_idx]->size = key_size;
hist_data->key_size = key_size;
hist_data->fields[key_idx]->offset = key_offset;
hist_data->key_size += key_size;
if (hist_data->key_size > HIST_KEY_SIZE_MAX) {
ret = -EINVAL;
goto out;
@ -399,7 +401,7 @@ static int create_key_field(struct hist_trigger_data *hist_data,
static int create_key_fields(struct hist_trigger_data *hist_data,
struct trace_event_file *file)
{
unsigned int i, n_vals = hist_data->n_vals;
unsigned int i, key_offset = 0, n_vals = hist_data->n_vals;
char *fields_str, *field_str;
int ret = -EINVAL;
@ -411,13 +413,15 @@ static int create_key_fields(struct hist_trigger_data *hist_data,
if (!fields_str)
goto out;
for (i = n_vals; i < n_vals + HIST_KEY_MAX; i++) {
for (i = n_vals; i < n_vals + TRACING_MAP_KEYS_MAX; i++) {
field_str = strsep(&fields_str, ",");
if (!field_str)
break;
ret = create_key_field(hist_data, i, file, field_str);
ret = create_key_field(hist_data, i, key_offset,
file, field_str);
if (ret < 0)
goto out;
key_offset += ret;
}
if (fields_str) {
ret = -EINVAL;
@ -482,7 +486,10 @@ static int create_tracing_map_fields(struct hist_trigger_data *hist_data)
else
cmp_fn = tracing_map_cmp_num(field->size,
field->is_signed);
idx = tracing_map_add_key_field(map, 0, cmp_fn);
idx = tracing_map_add_key_field(map,
hist_field->offset,
cmp_fn);
} else
idx = tracing_map_add_sum_field(map);
@ -562,12 +569,16 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
static void event_hist_trigger(struct event_trigger_data *data, void *rec)
{
struct hist_trigger_data *hist_data = data->private_data;
char compound_key[HIST_KEY_SIZE_MAX];
struct hist_field *key_field;
struct tracing_map_elt *elt;
u64 field_contents;
void *key = NULL;
unsigned int i;
if (hist_data->n_keys > 1)
memset(compound_key, 0, hist_data->key_size);
for_each_hist_key_field(i, hist_data) {
key_field = hist_data->fields[i];
@ -576,8 +587,16 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec)
key = (void *)(unsigned long)field_contents;
else
key = (void *)&field_contents;
if (hist_data->n_keys > 1) {
memcpy(compound_key + key_field->offset, key,
key_field->size);
}
}
if (hist_data->n_keys > 1)
key = compound_key;
elt = tracing_map_insert(hist_data->map, key);
if (elt)
hist_trigger_elt_update(hist_data, elt, rec);
@ -602,11 +621,11 @@ hist_trigger_entry_print(struct seq_file *m,
if (key_field->flags & HIST_FIELD_FL_STRING) {
seq_printf(m, "%s: %-50s", key_field->field->name,
(char *)key);
(char *)(key + key_field->offset));
} else {
uval = *(u64 *)key;
seq_printf(m, "%s: %10llu",
key_field->field->name, uval);
uval = *(u64 *)(key + key_field->offset);
seq_printf(m, "%s: %10llu", key_field->field->name,
uval);
}
}