On 2015/7/14 9:59, He Kuang wrote:
To print a trace event with a dynamic array, __print_array(array, len,
element_size) requires the number of items in the array, which can be
got by the helper function __get_dynamic_array_len(), currently it is
not an available function in the function list in process_function().
Add new arg type PRINT_DYNAMIC_ARRAY_LEN which returns the array
length embedded in the __data_loc_##item field to eval_num_arg().
Signed-off-by: He Kuang <heku...@huawei.com>
---
tools/lib/traceevent/event-parse.c | 52 ++++++++++++++++++++++
tools/lib/traceevent/event-parse.h | 1 +
.../util/scripting-engines/trace-event-python.c | 1 +
3 files changed, 54 insertions(+)
diff --git a/tools/lib/traceevent/event-parse.c
b/tools/lib/traceevent/event-parse.c
index cc25f05..55fc3b6c 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -783,6 +783,7 @@ static void free_arg(struct print_arg *arg)
free(arg->bitmask.bitmask);
break;
case PRINT_DYNAMIC_ARRAY:
+ case PRINT_DYNAMIC_ARRAY_LEN:
free(arg->dynarray.index);
break;
case PRINT_OP:
@@ -2655,6 +2656,42 @@ process_dynamic_array(struct event_format *event, struct
print_arg *arg, char **
}
static enum event_type
+process_dynamic_array_len(struct event_format *event, struct print_arg *arg,
+ char **tok)
+{
+ struct format_field *field;
+ enum event_type type;
+ char *token;
+
+ if (read_expect_type(EVENT_ITEM, &token) < 0)
+ goto out_free;
+
+ arg->type = PRINT_DYNAMIC_ARRAY_LEN;
+
+ /* Find the field */
+ field = pevent_find_field(event, token);
+ if (!field)
+ goto out_free;
+
+ arg->dynarray.field = field;
+ arg->dynarray.index = 0;
+
+ if (read_expected(EVENT_DELIM, ")") < 0)
+ goto out_err;
+
+ type = read_token(&token);
+ *tok = token;
+
+ return type;
+
+ out_free:
+ free_token(token);
+ out_err:
+ *tok = NULL;
+ return EVENT_ERROR;
+}
+
+static enum event_type
process_paren(struct event_format *event, struct print_arg *arg, char **tok)
{
struct print_arg *item_arg;
@@ -2901,6 +2938,10 @@ process_function(struct event_format *event, struct
print_arg *arg,
free_token(token);
return process_dynamic_array(event, arg, tok);
}
+ if (strcmp(token, "__get_dynamic_array_len") == 0) {
+ free_token(token);
+ return process_dynamic_array_len(event, arg, tok);
+ }
func = find_func_handler(event->pevent, token);
if (func) {
@@ -3581,6 +3622,17 @@ eval_num_arg(void *data, int size, struct event_format
*event, struct print_arg
goto out_warning_op;
}
break;
+ case PRINT_DYNAMIC_ARRAY_LEN:
+ offset = pevent_read_number(pevent,
+ data + arg->dynarray.field->offset,
+ arg->dynarray.field->size);
+ /*
+ * The actual length of the dynamic array is stored
+ * in the top half of the field, and the offset
+ * is in the bottom half of the 32 bit field.
+ */
+ val = (unsigned long long)(offset >> 16);
+ break;
case PRINT_DYNAMIC_ARRAY:
/* Without [], we pass the address to the dynamic data */
offset = pevent_read_number(pevent,
diff --git a/tools/lib/traceevent/event-parse.h
b/tools/lib/traceevent/event-parse.h
index 063b197..94543aa 100644
--- a/tools/lib/traceevent/event-parse.h
+++ b/tools/lib/traceevent/event-parse.h
@@ -294,6 +294,7 @@ enum print_arg_type {
PRINT_OP,
PRINT_FUNC,
PRINT_BITMASK,
+ PRINT_DYNAMIC_ARRAY_LEN,
};
struct print_arg {
diff --git a/tools/perf/util/scripting-engines/trace-event-python.c
b/tools/perf/util/scripting-engines/trace-event-python.c
index ace2484..d309341 100644
--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -253,6 +253,7 @@ static void define_event_symbols(struct event_format *event,
case PRINT_DYNAMIC_ARRAY:
case PRINT_FUNC:
case PRINT_BITMASK:
+ case PRINT_DYNAMIC_ARRAY_LEN:
Here is a small problem in this patch that, it only updates
trace-event-python.c, leaves
trace-event-perf.c unchanged. If CONFIG_LIBPERL is on, a compiling error
will raise.
I fixed this in my own git repository.
Steven, could you please cherry-pick this one instead?
https://github.com/WangNan0/linux/commit/951d78339e8c7819e9a1a9faeaf15e2c0b1aaa10
Note that the author field of it is still He Kuang.
Thank you.
/* we should warn... */
return;
}
--
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