[PATCH 16/19] perf tools: Add debug prints for ordered events queue

From: Jiri Olsa
Date: Fri Jul 25 2014 - 10:58:01 EST


Adding some prints for ordered events queue, to help
debug issues.

Adding debug_ordered_events debug variable to be able
to enable ordered events debug messages using:
$ perf --debug ordered-events=2 report ...

Also using oe pointer in perf_session_queue_event instead
of chained session variable dereferencing.

Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Corey Ashford <cjashfor@xxxxxxxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jean Pihet <jean.pihet@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
tools/perf/util/debug.c | 36 +++++++++++++++++++++++++++++++++++-
tools/perf/util/debug.h | 8 ++++++++
tools/perf/util/ordered-events.c | 26 ++++++++++++++++++++++++++
tools/perf/util/session.c | 4 +++-
4 files changed, 72 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
index 71d419362634..ba357f3226c6 100644
--- a/tools/perf/util/debug.c
+++ b/tools/perf/util/debug.c
@@ -13,8 +13,12 @@
#include "util.h"
#include "target.h"

+#define NSECS_PER_SEC 1000000000ULL
+#define NSECS_PER_USEC 1000ULL
+
int verbose;
bool dump_trace = false, quiet = false;
+int debug_ordered_events;

static int _eprintf(int level, int var, const char *fmt, va_list args)
{
@@ -42,6 +46,35 @@ int eprintf(int level, int var, const char *fmt, ...)
return ret;
}

+static int __eprintf_time(u64 t, const char *fmt, va_list args)
+{
+ int ret = 0;
+ u64 secs, usecs, nsecs = t;
+
+ secs = nsecs / NSECS_PER_SEC;
+ nsecs -= secs * NSECS_PER_SEC;
+ usecs = nsecs / NSECS_PER_USEC;
+
+ ret = fprintf(stderr, "[%13" PRIu64 ".%06" PRIu64 "] ",
+ secs, usecs);
+ ret += vfprintf(stderr, fmt, args);
+ return ret;
+}
+
+int eprintf_time(int level, int var, u64 t, const char *fmt, ...)
+{
+ int ret = 0;
+ va_list args;
+
+ if (var >= level) {
+ va_start(args, fmt);
+ ret = __eprintf_time(t, fmt, args);
+ va_end(args);
+ }
+
+ return ret;
+}
+
/*
* Overloading libtraceevent standard info print
* function, display with -v in perf.
@@ -110,7 +143,8 @@ static struct debug_variable {
const char *name;
int *ptr;
} debug_variables[] = {
- { .name = "verbose", .ptr = &verbose },
+ { .name = "verbose", .ptr = &verbose },
+ { .name = "ordered-events", .ptr = &debug_ordered_events},
{ .name = NULL, }
};

diff --git a/tools/perf/util/debug.h b/tools/perf/util/debug.h
index 89fb6b0f7ab2..1691af827605 100644
--- a/tools/perf/util/debug.h
+++ b/tools/perf/util/debug.h
@@ -10,6 +10,7 @@

extern int verbose;
extern bool quiet, dump_trace;
+extern int debug_ordered_events;

#ifndef pr_fmt
#define pr_fmt(fmt) fmt
@@ -29,6 +30,12 @@ extern bool quiet, dump_trace;
#define pr_debug3(fmt, ...) pr_debugN(3, pr_fmt(fmt), ##__VA_ARGS__)
#define pr_debug4(fmt, ...) pr_debugN(4, pr_fmt(fmt), ##__VA_ARGS__)

+#define pr_time_N(n, var, t, fmt, ...) \
+ eprintf_time(n, var, t, fmt, ##__VA_ARGS__)
+
+#define pr_oe_time(t, fmt, ...) pr_time_N(1, debug_ordered_events, t, pr_fmt(fmt), ##__VA_ARGS__)
+#define pr_oe_time2(t, fmt, ...) pr_time_N(2, debug_ordered_events, t, pr_fmt(fmt), ##__VA_ARGS__)
+
int dump_printf(const char *fmt, ...) __attribute__((format(printf, 1, 2)));
void trace_event(union perf_event *event);

@@ -38,6 +45,7 @@ int ui__warning(const char *format, ...) __attribute__((format(printf, 1, 2)));
void pr_stat(const char *fmt, ...);

int eprintf(int level, int var, const char *fmt, ...) __attribute__((format(printf, 3, 4)));
+int eprintf_time(int level, int var, u64 t, const char *fmt, ...) __attribute__((format(printf, 4, 5)));

int perf_debug_option(const char *str);

diff --git a/tools/perf/util/ordered-events.c b/tools/perf/util/ordered-events.c
index 6c48dfe24dc4..292cb627e51a 100644
--- a/tools/perf/util/ordered-events.c
+++ b/tools/perf/util/ordered-events.c
@@ -1,10 +1,16 @@
#include <linux/list.h>
+#include <linux/compiler.h>
#include "ordered-events.h"
#include "evlist.h"
#include "session.h"
#include "asm/bug.h"
#include "debug.h"

+#define pr_N(n, fmt, ...) \
+ eprintf(n, debug_ordered_events, fmt, ##__VA_ARGS__)
+
+#define pr(fmt, ...) pr_N(1, pr_fmt(fmt), ##__VA_ARGS__)
+
static void queue_event(struct ordered_events *oe, struct ordered_event *new)
{
struct ordered_event *last = oe->last;
@@ -14,6 +20,8 @@ static void queue_event(struct ordered_events *oe, struct ordered_event *new)
++oe->nr_events;
oe->last = new;

+ pr_oe_time2(timestamp, "queue_event nr_events %u\n", oe->nr_events);
+
if (!last) {
list_add(&new->list, &oe->events);
oe->max_timestamp = timestamp;
@@ -69,12 +77,17 @@ static struct ordered_event *alloc_event(struct ordered_events *oe)
if (!oe->buffer)
return NULL;

+ pr("alloc size %" PRIu64 "B (+%zu), max %" PRIu64 "B\n",
+ oe->cur_alloc_size, size, oe->max_alloc_size);
+
oe->cur_alloc_size += size;
list_add(&oe->buffer->list, &oe->to_free);

/* First entry is abused to maintain the to_free list. */
oe->buffer_idx = 2;
new = oe->buffer + 1;
+ } else {
+ pr("allocation limit reached %" PRIu64 "B\n", oe->max_alloc_size);
}

return new;
@@ -155,6 +168,11 @@ int ordered_events_flush(struct perf_session *s, struct perf_tool *tool,
enum oe_flush how)
{
struct ordered_events *oe = &s->ordered_events;
+ static const char * const str[] = {
+ "FINAL",
+ "ROUND",
+ "HALF ",
+ };
int err;

switch (how) {
@@ -184,6 +202,10 @@ int ordered_events_flush(struct perf_session *s, struct perf_tool *tool,
break;
};

+ pr_oe_time(oe->next_flush, "next_flush - ordered_events_flush PRE %s, nr_events %u\n",
+ str[how], oe->nr_events);
+ pr_oe_time(oe->max_timestamp, "max_timestamp\n");
+
err = __ordered_events_flush(s, tool);

if (!err) {
@@ -191,6 +213,10 @@ int ordered_events_flush(struct perf_session *s, struct perf_tool *tool,
oe->next_flush = oe->max_timestamp;
}

+ pr_oe_time(oe->next_flush, "next_flush - ordered_events_flush POST %s, nr_events %u\n",
+ str[how], oe->nr_events);
+ pr_oe_time(oe->last_flush, "last_flush\n");
+
return err;
}

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 4e748142a13f..fe868abd6c87 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -501,8 +501,10 @@ int perf_session_queue_event(struct perf_session *s, union perf_event *event,
if (!timestamp || timestamp == ~0ULL)
return -ETIME;

- if (timestamp < s->ordered_events.last_flush) {
+ if (timestamp < oe->last_flush) {
printf("Warning: Timestamp below last timeslice flush\n");
+ pr_oe_time(timestamp, "out of order event");
+ pr_oe_time(oe->last_flush, "last flush");
return -EINVAL;
}

--
1.8.3.1

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