linux/tools/perf/util/ordered-events.c
Jiri Olsa b0a45203a7 perf tools: Allow out of order messages in forced flush
In forced flush (OE_FLUSH__HALF) we break the rules of the flush
timestamp via PERF_RECORD_FINISHED_ROUND event, so we could get out of
order event.

Do not force error in this case plus changing the output warning to use
WARN_ONCE.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-8q8794a8nlmpd1u8xrqmcyd2@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-08-12 12:03:02 -03:00

246 lines
5.7 KiB
C

#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;
u64 timestamp = new->timestamp;
struct list_head *p;
++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;
return;
}
/*
* last event might point to some random place in the list as it's
* the last queued event. We expect that the new event is close to
* this.
*/
if (last->timestamp <= timestamp) {
while (last->timestamp <= timestamp) {
p = last->list.next;
if (p == &oe->events) {
list_add_tail(&new->list, &oe->events);
oe->max_timestamp = timestamp;
return;
}
last = list_entry(p, struct ordered_event, list);
}
list_add_tail(&new->list, &last->list);
} else {
while (last->timestamp > timestamp) {
p = last->list.prev;
if (p == &oe->events) {
list_add(&new->list, &oe->events);
return;
}
last = list_entry(p, struct ordered_event, list);
}
list_add(&new->list, &last->list);
}
}
#define MAX_SAMPLE_BUFFER (64 * 1024 / sizeof(struct ordered_event))
static struct ordered_event *alloc_event(struct ordered_events *oe)
{
struct list_head *cache = &oe->cache;
struct ordered_event *new = NULL;
if (!list_empty(cache)) {
new = list_entry(cache->next, struct ordered_event, list);
list_del(&new->list);
} else if (oe->buffer) {
new = oe->buffer + oe->buffer_idx;
if (++oe->buffer_idx == MAX_SAMPLE_BUFFER)
oe->buffer = NULL;
} else if (oe->cur_alloc_size < oe->max_alloc_size) {
size_t size = MAX_SAMPLE_BUFFER * sizeof(*new);
oe->buffer = malloc(size);
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;
}
struct ordered_event *
ordered_events__new(struct ordered_events *oe, u64 timestamp)
{
struct ordered_event *new;
new = alloc_event(oe);
if (new) {
new->timestamp = timestamp;
queue_event(oe, new);
}
return new;
}
void ordered_events__delete(struct ordered_events *oe, struct ordered_event *event)
{
list_move(&event->list, &oe->cache);
oe->nr_events--;
}
static int __ordered_events__flush(struct perf_session *s,
struct perf_tool *tool)
{
struct ordered_events *oe = &s->ordered_events;
struct list_head *head = &oe->events;
struct ordered_event *tmp, *iter;
struct perf_sample sample;
u64 limit = oe->next_flush;
u64 last_ts = oe->last ? oe->last->timestamp : 0ULL;
bool show_progress = limit == ULLONG_MAX;
struct ui_progress prog;
int ret;
if (!tool->ordered_events || !limit)
return 0;
if (show_progress)
ui_progress__init(&prog, oe->nr_events, "Processing time ordered events...");
list_for_each_entry_safe(iter, tmp, head, list) {
if (session_done())
return 0;
if (iter->timestamp > limit)
break;
ret = perf_evlist__parse_sample(s->evlist, iter->event, &sample);
if (ret)
pr_err("Can't parse sample, err = %d\n", ret);
else {
ret = perf_session__deliver_event(s, iter->event, &sample, tool,
iter->file_offset);
if (ret)
return ret;
}
ordered_events__delete(oe, iter);
oe->last_flush = iter->timestamp;
if (show_progress)
ui_progress__update(&prog, 1);
}
if (list_empty(head))
oe->last = NULL;
else if (last_ts <= limit)
oe->last = list_entry(head->prev, struct ordered_event, list);
return 0;
}
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[] = {
"NONE",
"FINAL",
"ROUND",
"HALF ",
};
int err;
switch (how) {
case OE_FLUSH__FINAL:
oe->next_flush = ULLONG_MAX;
break;
case OE_FLUSH__HALF:
{
struct ordered_event *first, *last;
struct list_head *head = &oe->events;
first = list_entry(head->next, struct ordered_event, list);
last = oe->last;
/* Warn if we are called before any event got allocated. */
if (WARN_ONCE(!last || list_empty(head), "empty queue"))
return 0;
oe->next_flush = first->timestamp;
oe->next_flush += (last->timestamp - first->timestamp) / 2;
break;
}
case OE_FLUSH__ROUND:
case OE_FLUSH__NONE:
default:
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) {
if (how == OE_FLUSH__ROUND)
oe->next_flush = oe->max_timestamp;
oe->last_flush_type = how;
}
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;
}
void ordered_events__init(struct ordered_events *oe)
{
INIT_LIST_HEAD(&oe->events);
INIT_LIST_HEAD(&oe->cache);
INIT_LIST_HEAD(&oe->to_free);
oe->max_alloc_size = (u64) -1;
oe->cur_alloc_size = 0;
}
void ordered_events__free(struct ordered_events *oe)
{
while (!list_empty(&oe->to_free)) {
struct ordered_event *event;
event = list_entry(oe->to_free.next, struct ordered_event, list);
list_del(&event->list);
free(event);
}
}