[PATCH 8/9] tracing: Add hist_field_name() accessor

From: Tom Zanussi
Date: Fri Sep 22 2017 - 15:59:58 EST


In preparation for hist_fields that won't be strictly based on
trace_event_fields, add a new hist_field_name() accessor to allow that
flexibility and update associated users.

Signed-off-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
---
kernel/trace/trace_events_hist.c | 67 +++++++++++++++++++++++++++-------------
1 file changed, 45 insertions(+), 22 deletions(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 4f6b640..4dc39e3 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -146,6 +146,23 @@ struct hist_trigger_data {
struct tracing_map *map;
};

+static const char *hist_field_name(struct hist_field *field,
+ unsigned int level)
+{
+ const char *field_name = "";
+
+ if (level > 1)
+ return field_name;
+
+ if (field->field)
+ field_name = field->field->name;
+
+ if (field_name == NULL)
+ field_name = "";
+
+ return field_name;
+}
+
static hist_field_fn_t select_value_fn(int field_size, int field_is_signed)
{
hist_field_fn_t fn = NULL;
@@ -653,7 +670,6 @@ static int is_descending(const char *str)
static int create_sort_keys(struct hist_trigger_data *hist_data)
{
char *fields_str = hist_data->attrs->sort_key_str;
- struct ftrace_event_field *field = NULL;
struct tracing_map_sort_key *sort_key;
int descending, ret = 0;
unsigned int i, j;
@@ -670,7 +686,9 @@ static int create_sort_keys(struct hist_trigger_data *hist_data)
}

for (i = 0; i < TRACING_MAP_SORT_KEYS_MAX; i++) {
+ struct hist_field *hist_field;
char *field_str, *field_name;
+ const char *test_name;

sort_key = &hist_data->sort_keys[i];

@@ -703,8 +721,10 @@ static int create_sort_keys(struct hist_trigger_data *hist_data)
}

for (j = 1; j < hist_data->n_fields; j++) {
- field = hist_data->fields[j]->field;
- if (field && (strcmp(field_name, field->name) == 0)) {
+ hist_field = hist_data->fields[j];
+ test_name = hist_field_name(hist_field, 0);
+
+ if (strcmp(field_name, test_name) == 0) {
sort_key->field_idx = j;
descending = is_descending(field_str);
if (descending < 0) {
@@ -952,6 +972,7 @@ static void hist_trigger_stacktrace_print(struct seq_file *m,
struct hist_field *key_field;
char str[KSYM_SYMBOL_LEN];
bool multiline = false;
+ const char *field_name;
unsigned int i;
u64 uval;

@@ -963,26 +984,27 @@ static void hist_trigger_stacktrace_print(struct seq_file *m,
if (i > hist_data->n_vals)
seq_puts(m, ", ");

+ field_name = hist_field_name(key_field, 0);
+
if (key_field->flags & HIST_FIELD_FL_HEX) {
uval = *(u64 *)(key + key_field->offset);
- seq_printf(m, "%s: %llx",
- key_field->field->name, uval);
+ seq_printf(m, "%s: %llx", field_name, uval);
} else if (key_field->flags & HIST_FIELD_FL_SYM) {
uval = *(u64 *)(key + key_field->offset);
sprint_symbol_no_offset(str, uval);
- seq_printf(m, "%s: [%llx] %-45s",
- key_field->field->name, uval, str);
+ seq_printf(m, "%s: [%llx] %-45s", field_name,
+ uval, str);
} else if (key_field->flags & HIST_FIELD_FL_SYM_OFFSET) {
uval = *(u64 *)(key + key_field->offset);
sprint_symbol(str, uval);
- seq_printf(m, "%s: [%llx] %-55s",
- key_field->field->name, uval, str);
+ seq_printf(m, "%s: [%llx] %-55s", field_name,
+ uval, str);
} else if (key_field->flags & HIST_FIELD_FL_EXECNAME) {
char *comm = elt->private_data;

uval = *(u64 *)(key + key_field->offset);
- seq_printf(m, "%s: %-16s[%10llu]",
- key_field->field->name, comm, uval);
+ seq_printf(m, "%s: %-16s[%10llu]", field_name,
+ comm, uval);
} else if (key_field->flags & HIST_FIELD_FL_SYSCALL) {
const char *syscall_name;

@@ -991,8 +1013,8 @@ static void hist_trigger_stacktrace_print(struct seq_file *m,
if (!syscall_name)
syscall_name = "unknown_syscall";

- seq_printf(m, "%s: %-30s[%3llu]",
- key_field->field->name, syscall_name, uval);
+ seq_printf(m, "%s: %-30s[%3llu]", field_name,
+ syscall_name, uval);
} else if (key_field->flags & HIST_FIELD_FL_STACKTRACE) {
seq_puts(m, "stacktrace:\n");
hist_trigger_stacktrace_print(m,
@@ -1000,15 +1022,14 @@ static void hist_trigger_stacktrace_print(struct seq_file *m,
HIST_STACKTRACE_DEPTH);
multiline = true;
} else if (key_field->flags & HIST_FIELD_FL_LOG2) {
- seq_printf(m, "%s: ~ 2^%-2llu", key_field->field->name,
+ seq_printf(m, "%s: ~ 2^%-2llu", field_name,
*(u64 *)(key + key_field->offset));
} else if (key_field->flags & HIST_FIELD_FL_STRING) {
- seq_printf(m, "%s: %-50s", key_field->field->name,
+ seq_printf(m, "%s: %-50s", field_name,
(char *)(key + key_field->offset));
} else {
uval = *(u64 *)(key + key_field->offset);
- seq_printf(m, "%s: %10llu", key_field->field->name,
- uval);
+ seq_printf(m, "%s: %10llu", field_name, uval);
}
}

@@ -1021,13 +1042,13 @@ static void hist_trigger_stacktrace_print(struct seq_file *m,
tracing_map_read_sum(elt, HITCOUNT_IDX));

for (i = 1; i < hist_data->n_vals; i++) {
+ field_name = hist_field_name(hist_data->fields[i], 0);
+
if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) {
- seq_printf(m, " %s: %10llx",
- hist_data->fields[i]->field->name,
+ seq_printf(m, " %s: %10llx", field_name,
tracing_map_read_sum(elt, i));
} else {
- seq_printf(m, " %s: %10llu",
- hist_data->fields[i]->field->name,
+ seq_printf(m, " %s: %10llu", field_name,
tracing_map_read_sum(elt, i));
}
}
@@ -1142,7 +1163,9 @@ static const char *get_hist_field_flags(struct hist_field *hist_field)

static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
{
- seq_printf(m, "%s", hist_field->field->name);
+ const char *field_name = hist_field_name(hist_field, 0);
+
+ seq_printf(m, "%s", field_name);
if (hist_field->flags) {
const char *flags_str = get_hist_field_flags(hist_field);

--
1.9.3