lkml.org 
[lkml]   [2017]   [Sep]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 33/40] tracing: Add hist trigger support for variable reference aliases
Date
Add support for alias=$somevar where alias can be used as
onmatch($alias).

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
---
kernel/trace/trace_events_hist.c | 61 ++++++++++++++++++++++++++++++++++++++--
1 file changed, 58 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 0782766..764c5e5 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -227,6 +227,7 @@ enum hist_field_flags {
HIST_FIELD_FL_EXPR = 16384,
HIST_FIELD_FL_VAR_REF = 32768,
HIST_FIELD_FL_CPU = 65536,
+ HIST_FIELD_FL_ALIAS = 131072,
};

struct var_defs {
@@ -1525,7 +1526,8 @@ static const char *hist_field_name(struct hist_field *field,

if (field->field)
field_name = field->field->name;
- else if (field->flags & HIST_FIELD_FL_LOG2)
+ else if (field->flags & HIST_FIELD_FL_LOG2 ||
+ field->flags & HIST_FIELD_FL_ALIAS)
field_name = hist_field_name(field->operands[0], ++level);
else if (field->flags & HIST_FIELD_FL_TIMESTAMP)
field_name = "$common_timestamp";
@@ -1961,7 +1963,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,

hist_field->hist_data = hist_data;

- if (flags & HIST_FIELD_FL_EXPR)
+ if (flags & HIST_FIELD_FL_EXPR || flags & HIST_FIELD_FL_ALIAS)
goto out; /* caller will populate */

if (flags & HIST_FIELD_FL_VAR_REF) {
@@ -2219,6 +2221,29 @@ static struct hist_field *parse_var_ref(struct trace_array *tr,
return field;
}

+static struct hist_field *create_alias(struct hist_trigger_data *hist_data,
+ struct hist_field *var_ref,
+ char *var_name)
+{
+ struct hist_field *alias = NULL;
+ unsigned long flags = HIST_FIELD_FL_ALIAS | HIST_FIELD_FL_VAR |
+ HIST_FIELD_FL_VAR_ONLY;
+
+ alias = create_hist_field(hist_data, NULL, flags, var_name);
+ if (!alias)
+ return NULL;
+
+ alias->fn = var_ref->fn;
+ alias->operands[0] = var_ref;
+
+ if (init_var_ref(alias, var_ref)) {
+ destroy_hist_field(alias, 0);
+ return NULL;
+ }
+
+ return alias;
+}
+
struct hist_field *parse_atom(struct hist_trigger_data *hist_data,
struct trace_event_file *file, char *str,
unsigned long *flags, char *var_name)
@@ -2245,6 +2270,13 @@ struct hist_field *parse_atom(struct hist_trigger_data *hist_data,
if (hist_field) {
hist_data->var_refs[hist_data->n_var_refs] = hist_field;
hist_field->var_ref_idx = hist_data->n_var_refs++;
+ if (var_name) {
+ hist_field = create_alias(hist_data, hist_field, var_name);
+ if (!hist_field) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
return hist_field;
}
} else
@@ -2346,6 +2378,26 @@ static int check_expr_operands(struct hist_field *operand1,
unsigned long operand1_flags = operand1->flags;
unsigned long operand2_flags = operand2->flags;

+ if ((operand1_flags & HIST_FIELD_FL_VAR_REF) ||
+ (operand1_flags & HIST_FIELD_FL_ALIAS)) {
+ struct hist_field *var;
+
+ var = find_var_field(operand1->var.hist_data, operand1->name);
+ if (!var)
+ return -EINVAL;
+ operand1_flags = var->flags;
+ }
+
+ if ((operand2_flags & HIST_FIELD_FL_VAR_REF) ||
+ (operand2_flags & HIST_FIELD_FL_ALIAS)) {
+ struct hist_field *var;
+
+ var = find_var_field(operand2->var.hist_data, operand2->name);
+ if (!var)
+ return -EINVAL;
+ operand2_flags = var->flags;
+ }
+
if ((operand1_flags & HIST_FIELD_FL_TIMESTAMP_USECS) !=
(operand2_flags & HIST_FIELD_FL_TIMESTAMP_USECS))
return -EINVAL;
@@ -4339,8 +4391,11 @@ static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
seq_puts(m, "$common_timestamp");
else if (hist_field->flags & HIST_FIELD_FL_CPU)
seq_puts(m, "cpu");
- else if (field_name)
+ else if (field_name) {
+ if (hist_field->flags & HIST_FIELD_FL_ALIAS)
+ seq_putc(m, '$');
seq_printf(m, "%s", field_name);
+ }

if (hist_field->flags) {
const char *flags_str = get_hist_field_flags(hist_field);
--
1.9.3
\
 
 \ /
  Last update: 2017-09-06 00:03    [W:0.361 / U:2.780 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site