[PATCH v2 4/4] tools lib traceevent: Added support for __get_bitmask() macro

Steven Rostedt
2014-06-03T03:23:07Z

[-- Attachment #1: 0004-tools-lib-traceevent-Added-support-for-__get_bitmask.patch --]
[-- Type: text/plain, Size: 8035 bytes --]

From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>

Coming in v3.16, trace events will be able to save bitmasks in raw
format in the ring buffer and output it with the __get_bitmask() macro.

In order for userspace tools to parse this, it must be able to handle
the __get_bitmask() call and be able to convert the data that's in
the ring buffer into a nice bitmask format. The output is similar to
what the kernel uses to print bitmasks, with a comma separator every
4 bytes (8 characters).

This allows for cpumasks to also be saved efficiently.

The first user is the thermal:thermal_power_limit event which has the
following output:

thermal_power_limit: cpus=0000000f freq=1900000 cdev_state=0 power=5252

Link: http://lkml.kernel.org/r/20140506132238.22e136d1@gandalf.local.home

Suggested-by: Javi Merino <javi.merino@arm.com>
Tested-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
tools/lib/traceevent/event-parse.c | 113 +++++++++++++++++++++
tools/lib/traceevent/event-parse.h | 7 ++
.../perf/util/scripting-engines/trace-event-perl.c | 1 +
.../util/scripting-engines/trace-event-python.c | 1 +
4 files changed, 122 insertions(+)

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index b83184f2d484..93825a17dcce 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -765,6 +765,9 @@ static void free_arg(struct print_arg *arg)
case PRINT_BSTRING:
free(arg->string.string);
break;
+ case PRINT_BITMASK:
+ free(arg->bitmask.bitmask);
+ break;
case PRINT_DYNAMIC_ARRAY:
free(arg->dynarray.index);
break;
@@ -2268,6 +2271,7 @@ static int arg_num_eval(struct print_arg *arg, long long *val)
case PRINT_FIELD ... PRINT_SYMBOL:
case PRINT_STRING:
case PRINT_BSTRING:
+ case PRINT_BITMASK:
default:
do_warning("invalid eval type %d", arg->type);
ret = 0;
@@ -2296,6 +2300,7 @@ static char *arg_eval (struct print_arg *arg)
case PRINT_FIELD ... PRINT_SYMBOL:
case PRINT_STRING:
case PRINT_BSTRING:
+ case PRINT_BITMASK:
default:
do_warning("invalid eval type %d", arg->type);
break;
@@ -2683,6 +2688,35 @@ process_str(struct event_format *event __maybe_unused, struct print_arg *arg,
return EVENT_ERROR;
}

+static enum event_type
+process_bitmask(struct event_format *event __maybe_unused, struct print_arg *arg,
+ char **tok)
+{
+ enum event_type type;
+ char *token;
+
+ if (read_expect_type(EVENT_ITEM, &token) < 0)
+ goto out_free;
+
+ arg->type = PRINT_BITMASK;
+ arg->bitmask.bitmask = token;
+ arg->bitmask.offset = -1;
+
+ 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 struct pevent_function_handler *
find_func_handler(struct pevent *pevent, char *func_name)
{
@@ -2797,6 +2831,10 @@ process_function(struct event_format *event, struct print_arg *arg,
free_token(token);
return process_str(event, arg, tok);
}
+ if (strcmp(token, "__get_bitmask") == 0) {
+ free_token(token);
+ return process_bitmask(event, arg, tok);
+ }
if (strcmp(token, "__get_dynamic_array") == 0) {
free_token(token);
return process_dynamic_array(event, arg, tok);
@@ -3324,6 +3362,7 @@ eval_num_arg(void *data, int size, struct event_format *event, struct print_arg
return eval_type(val, arg, 0);
case PRINT_STRING:
case PRINT_BSTRING:
+ case PRINT_BITMASK:
return 0;
case PRINT_FUNC: {
struct trace_seq s;
@@ -3556,6 +3595,60 @@ static void print_str_to_seq(struct trace_seq *s, const char *format,
trace_seq_printf(s, format, str);
}

+static void print_bitmask_to_seq(struct pevent *pevent,
+ struct trace_seq *s, const char *format,
+ int len_arg, const void *data, int size)
+{
+ int nr_bits = size * 8;
+ int str_size = (nr_bits + 3) / 4;
+ int len = 0;
+ char buf[3];
+ char *str;
+ int index;
+ int i;
+
+ /*
+ * The kernel likes to put in commas every 32 bits, we
+ * can do the same.
+ */
+ str_size += (nr_bits - 1) / 32;
+
+ str = malloc(str_size + 1);
+ if (!str) {
+ do_warning("%s: not enough memory!", __func__);
+ return;
+ }
+ str[str_size] = 0;
+
+ /* Start out with -2 for the two chars per byte */
+ for (i = str_size - 2; i >= 0; i -= 2) {
+ /*
+ * data points to a bit mask of size bytes.
+ * In the kernel, this is an array of long words, thus
+ * endianess is very important.
+ */
+ if (pevent->file_bigendian)
+ index = size - (len + 1);
+ else
+ index = len;
+
+ snprintf(buf, 3, "%02x", *((unsigned char *)data + index));
+ memcpy(str + i, buf, 2);
+ len++;
+ if (!(len & 3) && i > 0) {
+ i--;
+ str[i] = ',';
+ }
+ }
+
+ if (len_arg >= 0)
+ trace_seq_printf(s, format, len_arg, str);
+ else
+ trace_seq_printf(s, format, str);
+
+ free(str);
+}
+
static void print_str_arg(struct trace_seq *s, void *data, int size,
struct event_format *event, const char *format,
int len_arg, struct print_arg *arg)
@@ -3691,6 +3784,23 @@ static void print_str_arg(struct trace_seq *s, void *data, int size,
case PRINT_BSTRING:
print_str_to_seq(s, format, len_arg, arg->string.string);
break;
+ case PRINT_BITMASK: {
+ int bitmask_offset;
+ int bitmask_size;
+
+ if (arg->bitmask.offset == -1) {
+ struct format_field *f;
+
+ f = pevent_find_any_field(event, arg->bitmask.bitmask);
+ arg->bitmask.offset = f->offset;
+ }
+ bitmask_offset = data2host4(pevent, data + arg->bitmask.offset);
+ bitmask_size = bitmask_offset >> 16;
+ bitmask_offset &= 0xffff;
+ print_bitmask_to_seq(pevent, s, format, len_arg,
+ data + bitmask_offset, bitmask_size);
+ break;
+ }
case PRINT_OP:
/*
* The only op for string should be ? :
@@ -4822,6 +4932,9 @@ static void print_args(struct print_arg *args)
case PRINT_BSTRING:
printf("__get_str(%s)", args->string.string);
break;
+ case PRINT_BITMASK:
+ printf("__get_bitmask(%s)", args->bitmask.bitmask);
+ break;
case PRINT_TYPE:
printf("(%s)", args->typecast.type);
print_args(args->typecast.item);
diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h
index 56e0e6c12411..7a3873ff9a4f 100644
--- a/tools/lib/traceevent/event-parse.h
+++ b/tools/lib/traceevent/event-parse.h
@@ -208,6 +208,11 @@ struct print_arg_string {
int offset;
};

+struct print_arg_bitmask {
+ char *bitmask;
+ int offset;
+};
+
struct print_arg_field {
char *name;
struct format_field *field;
@@ -274,6 +279,7 @@ enum print_arg_type {
PRINT_DYNAMIC_ARRAY,
PRINT_OP,
PRINT_FUNC,
+ PRINT_BITMASK,
};

struct print_arg {
@@ -288,6 +294,7 @@ struct print_arg {
struct print_arg_hex hex;
struct print_arg_func func;
struct print_arg_string string;
+ struct print_arg_bitmask bitmask;
struct print_arg_op op;
struct print_arg_dynarray dynarray;
};
diff --git a/tools/perf/util/scripting-engines/trace-event-perl.c b/tools/perf/util/scripting-engines/trace-event-perl.c
index e108207c5de0..af7da565a750 100644
--- a/tools/perf/util/scripting-engines/trace-event-perl.c
+++ b/tools/perf/util/scripting-engines/trace-event-perl.c
@@ -215,6 +215,7 @@ static void define_event_symbols(struct event_format *event,
case PRINT_BSTRING:
case PRINT_DYNAMIC_ARRAY:
case PRINT_STRING:
+ case PRINT_BITMASK:
break;
case PRINT_TYPE:
define_event_symbols(event, ev_name, args->typecast.item);
diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
index cd9774df3750..c3de0971bfdd 100644
--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -197,6 +197,7 @@ static void define_event_symbols(struct event_format *event,
case PRINT_BSTRING:
case PRINT_DYNAMIC_ARRAY:
case PRINT_FUNC:
+ case PRINT_BITMASK:
/* we should warn... */
return;
}
--
2.0.0.rc2