blob: 1f28fbf254ecab15a491989524b6b91aa67a1bbd [file] [log] [blame]
From 82cc9ce0e494a51282e849a2898c5611a8a6221f Mon Sep 17 00:00:00 2001
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Date: Fri, 22 Sep 2017 14:58:23 -0500
Subject: [PATCH 1745/1795] tracing: Reimplement log2
log2 as currently implemented applies only to u64 trace_event_field
derived fields, and assumes that anything it's applied to is a u64
field.
To prepare for synthetic fields like latencies, log2 should be
applicable to those as well, so take the opportunity now to fix the
current problems as well as expand to more general uses.
log2 should be thought of as a chaining function rather than a field
type. To enable this as well as possible future function
implementations, add a hist_field operand array into the hist_field
definition for this purpose, and make use of it to implement the log2
'function'.
Link: http://lkml.kernel.org/r/b47f93fc0b87b36eccf716b0c018f3a71e1f1111.1506105045.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
(cherry picked from commit 5819eaddf35b24d628ddfa4fbb5f8d4026e44b96)
Signed-off-by: Hirotaka MOTAI <Motai.Hirotaka@aj.MitsubishiElectric.co.jp>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
kernel/trace/trace_events_hist.c | 31 +++++++++++++++++++++++++++----
1 file changed, 27 insertions(+), 4 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 34edf5fd85fd..1e1558c99d56 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -28,12 +28,16 @@ struct hist_field;
typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event);
+#define HIST_FIELD_OPERANDS_MAX 2
+
struct hist_field {
struct ftrace_event_field *field;
unsigned long flags;
hist_field_fn_t fn;
unsigned int size;
unsigned int offset;
+ unsigned int is_signed;
+ struct hist_field *operands[HIST_FIELD_OPERANDS_MAX];
};
static u64 hist_field_none(struct hist_field *field, void *event)
@@ -71,7 +75,9 @@ static u64 hist_field_pstring(struct hist_field *hist_field, void *event)
static u64 hist_field_log2(struct hist_field *hist_field, void *event)
{
- u64 val = *(u64 *)(event + hist_field->field->offset);
+ struct hist_field *operand = hist_field->operands[0];
+
+ u64 val = operand->fn(operand, event);
return (u64) ilog2(roundup_pow_of_two(val));
}
@@ -156,6 +162,8 @@ 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)
+ field_name = hist_field_name(field->operands[0], ++level);
if (field_name == NULL)
field_name = "";
@@ -357,8 +365,20 @@ static const struct tracing_map_ops hist_trigger_elt_comm_ops = {
.elt_init = hist_trigger_elt_comm_init,
};
-static void destroy_hist_field(struct hist_field *hist_field)
+static void destroy_hist_field(struct hist_field *hist_field,
+ unsigned int level)
{
+ unsigned int i;
+
+ if (level > 2)
+ return;
+
+ if (!hist_field)
+ return;
+
+ for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++)
+ destroy_hist_field(hist_field->operands[i], level + 1);
+
kfree(hist_field);
}
@@ -385,7 +405,10 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field,
}
if (flags & HIST_FIELD_FL_LOG2) {
+ unsigned long fl = flags & ~HIST_FIELD_FL_LOG2;
hist_field->fn = hist_field_log2;
+ hist_field->operands[0] = create_hist_field(field, fl);
+ hist_field->size = hist_field->operands[0]->size;
goto out;
}
@@ -405,7 +428,7 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field,
hist_field->fn = select_value_fn(field->size,
field->is_signed);
if (!hist_field->fn) {
- destroy_hist_field(hist_field);
+ destroy_hist_field(hist_field, 0);
return NULL;
}
}
@@ -422,7 +445,7 @@ static void destroy_hist_fields(struct hist_trigger_data *hist_data)
for (i = 0; i < TRACING_MAP_FIELDS_MAX; i++) {
if (hist_data->fields[i]) {
- destroy_hist_field(hist_data->fields[i]);
+ destroy_hist_field(hist_data->fields[i], 0);
hist_data->fields[i] = NULL;
}
}
--
2.19.0