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tools lib traceevent: Added support for __get_bitmask() macro 

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>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Javi Merino <javi.merino@arm.com>
Link: http://lkml.kernel.org/r/20140603032224.229186537@goodmis.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
This commit is contained in:
Steven Rostedt (Red Hat) 2014-06-02 23:20:16 -04:00 committed by Jiri Olsa
parent 49440828ad
commit 473a778a2f
4 changed files with 122 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

113
tools/lib/traceevent/event-parse.c
View File

@ -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);

7
tools/lib/traceevent/event-parse.h
View File

@ -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;
};

1
tools/perf/util/scripting-engines/trace-event-perl.c
View File

@ -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);

1
tools/perf/util/scripting-engines/trace-event-python.c
View File

@ -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;
}