[PATCH 02/11] tracing: add nsec2sec print formats

From: Steven Rostedt
Date: Wed Jun 10 2009 - 01:43:53 EST


From: Steven Rostedt <srostedt@xxxxxxxxxx>

This patch adds the tags nsec2sec, nsec2usec and nsec2msec tags that
will do the conversion of a nsec unsigned long long value into a
printf("%lu.%0*lu", precision, nsec) format.

The tags are:

<nsec2sec:precision:field>
<nsec2msec:precision:field>
<nsec2usec:precision:field>

For example, having the field ns that holds an unsigned long long
nanosecond value, we can do:

<nsec2sec:6:ns>

That will produce something like:

23.123456 as a value, if ns was 23123456789.

Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
kernel/trace/trace_read_binary.c | 189 +++++++++++++++++++++++++++++++-------
1 files changed, 154 insertions(+), 35 deletions(-)

diff --git a/kernel/trace/trace_read_binary.c b/kernel/trace/trace_read_binary.c
index b47285d..e2cb6c4 100644
--- a/kernel/trace/trace_read_binary.c
+++ b/kernel/trace/trace_read_binary.c
@@ -21,7 +21,9 @@ static struct trace_seq buffer;
*
* FMT := constant string FMT | COMMAND FMT | empty
* COMMAND := <TYPE:FIELD> | <mask:FIELD:DELIM:MASKS> | <sym:FIELD:SYMBOLS> |
- * <if:FIELD:TRUE:FALSE> | <ifmask:FIELD:MASK:TRUE:FALSE>
+ * <if:FIELD:TRUE:FALSE> | <ifmask:FIELD:MASK:TRUE:FALSE> |
+ * <nsec2sec:PRECISION:FIELD> | <nsec2usec:PRECISION:FIELD> |
+ * <nsec2msec:PRECISION:FIELD>
* TYPE := int | uint | hex | ptr | string | strarray
* FIELD := defined by the event structure
* MASKS := MASK=NAME,MASKS | MASK=NAME
@@ -34,6 +36,30 @@ static struct trace_seq buffer;
* NAME := the name to write when a match is found
*
* A '\<' would print '<'
+ *
+ * Commands:
+ * int : Print the field out as an signed integer. The size of the field
+ * determines if it is a char, short, long, or long long.
+ * uint : Same as int, but for unsigned.
+ * hex : Print the field as a hex (ie. 0x4ab)
+ * ptr : Print the field as a hex but without the '0x'.
+ * string : Used with dynamic sized strings (__string)
+ * strarray : Used with static sized arrays (__array ( char , item, len)).
+ * if : If the field is non zero, print the TRUE text,
+ * otherwise print FALSE text.
+ * ifmask : If the bit in MASK in the field is set,
+ * then print the TRUE text, otherwise print FALSE text.
+ * nsec2sec : Convert a nsec field into secs in the format:
+ * printf("%lu.%0Plu", field), where PRECISION defines what 'P' is.
+ * nsec2usec : Same as nsec2sec but will convert to usec.
+ * nsec2usec : Same as nsec2sec but will convert to msec.
+ * mask : Print out the values of a bit mask. Each matching mask will
+ * print its name. The order does matter. Mask of '0' is special
+ * for it will print only if the value matches zero. The given
+ * DELIM will separate the different masks.
+ * sym : Print out the name of a matching value. This is similar to
+ * mask, but only one value may print.
+ *
*/

#define TOK_SIZE 32
@@ -49,6 +75,9 @@ enum field_types {
FIELD_IS_STRING,
FIELD_IS_STRARRAY,
FIELD_IS_HEX,
+ FIELD_IS_NSEC2SEC,
+ FIELD_IS_NSEC2USEC,
+ FIELD_IS_NSEC2MSEC,
FIELD_IS_MASK,
FIELD_IS_SYMBOL,
};
@@ -81,6 +110,10 @@ struct print_info {
} cond;
struct {
struct ftrace_event_field *field;
+ unsigned int precision;
+ } time;
+ struct {
+ struct ftrace_event_field *field;
struct list_head masks;
unsigned short delim;
unsigned short len;
@@ -217,6 +250,22 @@ add_if(struct ftrace_event_call *call, enum field_types type,
return 0;
}

+static int
+add_time(struct ftrace_event_call *call, enum field_types type,
+ struct ftrace_event_field *field, unsigned int precision)
+{
+ struct print_info *info;
+
+ info = alloc_print_info(call, type);
+ if (!info)
+ return -ENOMEM;
+
+ info->time.field = field;
+ info->time.precision = precision;
+
+ return 0;
+}
+
static int add_sym_mask(struct ftrace_event_call *call, struct list_head *list,
unsigned long long val,
const char *start, const char *end)
@@ -344,6 +393,7 @@ handle_field(struct ftrace_event_call *event,
const char *end, *tok, *delim;
unsigned long long mask;
unsigned int delim_len;
+ unsigned long precision;
int ret;

end = strchr(fmt, '>');
@@ -392,6 +442,26 @@ handle_field(struct ftrace_event_call *event,
return NULL;
break;

+ case FIELD_IS_NSEC2SEC:
+ case FIELD_IS_NSEC2USEC:
+ case FIELD_IS_NSEC2MSEC:
+ tok = strchr(fmt, ':');
+ if (!tok || tok > end)
+ goto out_err;
+
+ precision = simple_strtoul(fmt, NULL, 0);
+
+ fmt = tok + 1;
+
+ field = find_field(event, fmt, end - fmt);
+ if (!field)
+ goto out_err;
+
+ ret = add_time(event, field_type, field, precision);
+ if (ret)
+ return NULL;
+ break;
+
case FIELD_IS_MASK:
case FIELD_IS_SYMBOL:
tok = strchr(fmt, ':');
@@ -517,6 +587,15 @@ ftrace_initialize_print(struct ftrace_event_call *event, const char *fmt, ...)
else if (strncmp(fmt, "ifmask:", 7) == 0)
field_type = FIELD_IS_IFMASK;

+ else if (strncmp(fmt, "nsec2sec:", 9) == 0)
+ field_type = FIELD_IS_NSEC2SEC;
+
+ else if (strncmp(fmt, "nsec2usec:", 10) == 0)
+ field_type = FIELD_IS_NSEC2USEC;
+
+ else if (strncmp(fmt, "nsec2msec:", 10) == 0)
+ field_type = FIELD_IS_NSEC2MSEC;
+
else if (strncmp(fmt, "mask:", 5) == 0)
field_type = FIELD_IS_MASK;

@@ -613,6 +692,39 @@ trace_read_symbol(struct trace_seq *s, unsigned long long val,

}

+#define BAD_SIZE 0xdeadbeaf
+
+static unsigned long long
+get_val(void *p, int size, unsigned long long *mask)
+{
+ unsigned long long val;
+
+ switch (size) {
+ case 1:
+ val = *(char *)p;
+ *mask = 0xffULL;
+ break;
+ case 2:
+ val = *(short *)p;
+ *mask = 0xffffULL;
+ break;
+ case 4:
+ val = *(int *)p;
+ *mask = 0xffffffffULL;
+ break;
+ case 8:
+ val = *(long long *)p;
+ *mask = 0;
+ break;
+ default:
+ /* pass back a bad mask on error */
+ *mask = BAD_SIZE;
+ return 0;
+ }
+
+ return val;
+}
+
char *
ftrace_read_binary(struct trace_seq *s, struct ftrace_event_call *event,
struct trace_entry *entry)
@@ -621,6 +733,7 @@ ftrace_read_binary(struct trace_seq *s, struct ftrace_event_call *event,
struct print_info *info;
char *start = s->buffer + s->len;
struct ftrace_event_field *field;
+ unsigned long divisor, rem;
void *p;

if (!event->print_text) {
@@ -654,25 +767,8 @@ ftrace_read_binary(struct trace_seq *s, struct ftrace_event_call *event,
skip_if:
p += field->offset;

- switch (field->size) {
- case 1:
- val = *(char *)p;
- mask = 0xffULL;
- break;
- case 2:
- val = *(short *)p;
- mask = 0xffffULL;
- break;
- case 4:
- val = *(int *)p;
- mask = 0xffffffffULL;
- break;
- case 8:
- val = *(long long *)p;
- mask = 0;
- break;
-
- default:
+ val = get_val(p, field->size, &mask);
+ if (mask == BAD_SIZE) {
trace_seq_printf(s,
"<error: bad field size %d?>\n",
field->size);
@@ -723,32 +819,55 @@ ftrace_read_binary(struct trace_seq *s, struct ftrace_event_call *event,
trace_seq_puts(s, p);
break;

+ case FIELD_IS_NSEC2USEC:
+ divisor = NSEC_PER_USEC;
+ goto do_time;
+ case FIELD_IS_NSEC2MSEC:
+ divisor = NSEC_PER_MSEC;
+ goto do_time;
+ case FIELD_IS_NSEC2SEC:
+ divisor = NSEC_PER_SEC;
+
+ do_time:
+ field = info->time.field;
+
+ p += field->offset;
+
+ val = get_val(p, field->size, &mask);
+
+ if (mask == BAD_SIZE) {
+ trace_seq_printf(s,
+ "<error: bad field size %d?>\n",
+ field->size);
+ return start;
+ }
+
+ rem = do_div(val, divisor);
+ if (info->time.precision)
+ trace_seq_printf(s, "%llu.%0*lu",
+ val, info->time.precision,
+ rem);
+ else
+ trace_seq_printf(s, "%llu", val);
+
+ break;
+
case FIELD_IS_MASK:
case FIELD_IS_SYMBOL:

p += info->sym_mask.field->offset;

- switch (info->sym_mask.field->size) {
- case 1:
- val = *(unsigned char *)p;
- break;
- case 2:
- val = *(unsigned short *)p;
- break;
- case 4:
- val = *(unsigned int *)p;
- break;
- case 8:
- val = *(unsigned long long *)p;
- break;
-
- default:
+ val = get_val(p, info->sym_mask.field->size, &mask);
+
+ if (mask == BAD_SIZE) {
trace_seq_printf(s,
"<error: bad field size %d?>\n",
info->sym_mask.field->size);
return start;
}

+ val &= mask;
+
if (info->type == FIELD_IS_MASK)
trace_read_mask(s, val, info, event);
else
--
1.6.3.1

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