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|
/* ft2sort -- Sort Feather-Trace events in a binary file by sequence number.
* Copyright (C) 2011,2012 B. Brandenburg.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <sys/time.h>
#include <errno.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/mman.h>
#include "mapping.h"
#include "timestamp.h"
static unsigned int holes = 0;
static unsigned int non_monotonic = 0;
static unsigned int reordered = 0;
static unsigned int aborted_moves = 0;
static unsigned int implausible = 0;
static int want_verbose = 0;
double cycles_per_nanosecond = 0;
#define LOOK_AHEAD 1024
#define MAX_NR_NOT_IN_RANGE 5
#define MAX_CPUS UINT8_MAX
/* wall-clock time in seconds */
double wctime(void)
{
struct timeval tv;
gettimeofday(&tv, NULL);
return (tv.tv_sec + 1E-6 * tv.tv_usec);
}
static uint32_t next_seq_number(uint32_t seqno)
{
return seqno + 1;
}
struct timestamp* find_forward_by_seq_no(struct timestamp* start,
struct timestamp* end,
uint32_t seq_no)
{
struct timestamp *pos;
if (end > start + LOOK_AHEAD)
end = start + LOOK_AHEAD;
for (pos = start; pos < end; pos++)
if (pos->seq_no == seq_no)
return pos;
return NULL;
}
static void mark_as_bad(struct timestamp *ts)
{
if (want_verbose)
printf("marking %s on cpu %u at %llu as bad\n",
event2str(ts->event), ts->cpu,
(unsigned long long) ts->timestamp);
ts->event = UINT8_MAX;
non_monotonic++;
}
static int in_range(uint32_t seqno, uint32_t candidate)
{
uint32_t upper_bound = seqno + LOOK_AHEAD;
uint32_t diff = candidate - seqno;
return (upper_bound < seqno && candidate < seqno && candidate < upper_bound) ||
(candidate >= seqno && diff < LOOK_AHEAD);
}
#define OVERFLOW_CUTOFF ((int32_t)UINT16_MAX / 2)
static int is_lower_seqno(int32_t candidate, int32_t min)
{
/* compute difference in sequence numbers without overflow */
int64_t delta = (int64_t) min - (int64_t) candidate;
return (delta >= 0 && delta <= OVERFLOW_CUTOFF) ||
(delta < -OVERFLOW_CUTOFF);
}
struct timestamp* find_lowest_seq_no(struct timestamp* start,
struct timestamp* end,
uint32_t seqno)
{
struct timestamp *pos, *min = NULL;
int nr_not_in_range = 0;
if (end > start + LOOK_AHEAD)
end = start + LOOK_AHEAD;
for (pos = start; pos != end && (!min || min->seq_no != seqno); pos++) {
/* pre-filter totally out-of-order samples */
if (in_range(seqno, pos->seq_no) &&
(!min || is_lower_seqno(pos->seq_no, min->seq_no))) {
min = pos;
} else if (!in_range(seqno, pos->seq_no)) {
if (++nr_not_in_range > MAX_NR_NOT_IN_RANGE)
return NULL;
}
}
return min;
}
static void move_record(struct timestamp* target, struct timestamp* pos)
{
struct timestamp tmp, *prev;
for (prev = target; prev < pos; prev++) {
/* Refuse to violate task and CPU sequentiality: since CPUs and
* tasks execute sequentially, it makes no sense to move a
* timestamp before something recorded by the same task or
* CPU. Exception: TS_SEND_RESCHED_START is actually recorded
* on a different CPU, so it is not subject to sequentiality
* constraints.*/
if (prev->event != TS_SEND_RESCHED_START &&
pos->event != TS_SEND_RESCHED_START &&
(prev->cpu == pos->cpu ||
(prev->pid == pos->pid && pos->pid != 0))) {
/* Bail out before we cause more disturbance to the
* stream. */
aborted_moves++;
if (want_verbose)
printf("Sequentiality constraint:\n"
"\t<ev:%s seq:%u pid:%u cpu:%u at %llu>\n"
"\tmust come before\n"
"\t<ev:%s seq:%u pid:%u cpu:%u at %llu>\n",
event2str(prev->event),
prev->seq_no, prev->pid, prev->cpu,
(unsigned long long) prev->timestamp,
event2str(pos->event),
|
