1 files changed, 391 insertions, 188 deletions

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index fa9d652c2dc3..6fb4694d05fa 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -65,9 +65,49 @@ out_close:
         return -1;
 }
 
+static void perf_session__id_header_size(struct perf_session *session)
+{
+       struct sample_data *data;
+       u64 sample_type = session->sample_type;
+       u16 size = 0;
+
+        if (!session->sample_id_all)
+                goto out;
+
+       if (sample_type & PERF_SAMPLE_TID)
+               size += sizeof(data->tid) * 2;
+
+       if (sample_type & PERF_SAMPLE_TIME)
+               size += sizeof(data->time);
+
+       if (sample_type & PERF_SAMPLE_ID)
+               size += sizeof(data->id);
+
+       if (sample_type & PERF_SAMPLE_STREAM_ID)
+               size += sizeof(data->stream_id);
+
+       if (sample_type & PERF_SAMPLE_CPU)
+               size += sizeof(data->cpu) * 2;
+out:
+       session->id_hdr_size = size;
+}
+
+void perf_session__set_sample_id_all(struct perf_session *session, bool value)
+{
+        session->sample_id_all = value;
+        perf_session__id_header_size(session);
+}
+
+void perf_session__set_sample_type(struct perf_session *session, u64 type)
+{
+        session->sample_type = type;
+}
+
 void perf_session__update_sample_type(struct perf_session *self)
 {
         self->sample_type = perf_header__sample_type(&self->header);
+        self->sample_id_all = perf_header__sample_id_all(&self->header);
+        perf_session__id_header_size(self);
 }
 
 int perf_session__create_kernel_maps(struct perf_session *self)
@@ -85,7 +125,9 @@ static void perf_session__destroy_kernel_maps(struct perf_session *self)
         machines__destroy_guest_kernel_maps(&self->machines);
 }
 
-struct perf_session *perf_session__new(const char *filename, int mode, bool force, bool repipe)
+struct perf_session *perf_session__new(const char *filename, int mode,
+                                       bool force, bool repipe,
+                                       struct perf_event_ops *ops)
 {
         size_t len = filename ? strlen(filename) + 1 : 0;
         struct perf_session *self = zalloc(sizeof(*self) + len);
@@ -101,10 +143,20 @@ struct perf_session *perf_session__new(const char *filename, int mode, bool forc
         INIT_LIST_HEAD(&self->dead_threads);
         self->hists_tree = RB_ROOT;
         self->last_match = NULL;
-        self->mmap_window = 32;
+        /*
+         * On 64bit we can mmap the data file in one go. No need for tiny mmap
+         * slices. On 32bit we use 32MB.
+         */
+#if BITS_PER_LONG == 64
+        self->mmap_window = ULLONG_MAX;
+#else
+        self->mmap_window = 32 * 1024 * 1024ULL;
+#endif
         self->machines = RB_ROOT;
         self->repipe = repipe;
-        INIT_LIST_HEAD(&self->ordered_samples.samples_head);
+        INIT_LIST_HEAD(&self->ordered_samples.samples);
+        INIT_LIST_HEAD(&self->ordered_samples.sample_cache);
+        INIT_LIST_HEAD(&self->ordered_samples.to_free);
         machine__init(&self->host_machine, "", HOST_KERNEL_ID);
 
         if (mode == O_RDONLY) {
@@ -120,6 +172,13 @@ struct perf_session *perf_session__new(const char *filename, int mode, bool forc
         }
 
         perf_session__update_sample_type(self);
+
+        if (ops && ops->ordering_requires_timestamps &&
+            ops->ordered_samples && !self->sample_id_all) {
+                dump_printf("WARNING: No sample_id_all support, falling back to unordered processing\n");
+                ops->ordered_samples = false;
+        }
+
 out:
         return self;
 out_free:
@@ -230,7 +289,15 @@ struct map_symbol *perf_session__resolve_callchain(struct perf_session *self,
         return syms;
 }
 
+static int process_event_synth_stub(event_t *event __used,
+                                    struct perf_session *session __used)
+{
+        dump_printf(": unhandled!\n");
+        return 0;
+}
+
 static int process_event_stub(event_t *event __used,
+                              struct sample_data *sample __used,
                               struct perf_session *session __used)
 {
         dump_printf(": unhandled!\n");
@@ -262,7 +329,7 @@ static void perf_event_ops__fill_defaults(struct perf_event_ops *handler)
         if (handler->exit == NULL)
                 handler->exit = process_event_stub;
         if (handler->lost == NULL)
-                handler->lost = process_event_stub;
+                handler->lost = event__process_lost;
         if (handler->read == NULL)
                 handler->read = process_event_stub;
         if (handler->throttle == NULL)
@@ -270,13 +337,13 @@ static void perf_event_ops__fill_defaults(struct perf_event_ops *handler)
         if (handler->unthrottle == NULL)
                 handler->unthrottle = process_event_stub;
         if (handler->attr == NULL)
-                handler->attr = process_event_stub;
+                handler->attr = process_event_synth_stub;
         if (handler->event_type == NULL)
-                handler->event_type = process_event_stub;
+                handler->event_type = process_event_synth_stub;
         if (handler->tracing_data == NULL)
-                handler->tracing_data = process_event_stub;
+                handler->tracing_data = process_event_synth_stub;
         if (handler->build_id == NULL)
-                handler->build_id = process_event_stub;
+                handler->build_id = process_event_synth_stub;
         if (handler->finished_round == NULL) {
                 if (handler->ordered_samples)
                         handler->finished_round = process_finished_round;
@@ -386,33 +453,61 @@ static event__swap_op event__swap_ops[] = {
 
 struct sample_queue {
         u64                     timestamp;
-        struct sample_event     *event;
+        u64                     file_offset;
+        event_t                 *event;
         struct list_head        list;
 };
 
+static void perf_session_free_sample_buffers(struct perf_session *session)
+{
+        struct ordered_samples *os = &session->ordered_samples;
+
+        while (!list_empty(&os->to_free)) {
+                struct sample_queue *sq;
+
+                sq = list_entry(os->to_free.next, struct sample_queue, list);
+                list_del(&sq->list);
+                free(sq);
+        }
+}
+
+static int perf_session_deliver_event(struct perf_session *session,
+                                      event_t *event,
+                                      struct sample_data *sample,
+                                      struct perf_event_ops *ops,
+                                      u64 file_offset);
+
 static void flush_sample_queue(struct perf_session *s,
                                struct perf_event_ops *ops)
 {
-        struct list_head *head = &s->ordered_samples.samples_head;
-        u64 limit = s->ordered_samples.next_flush;
+        struct ordered_samples *os = &s->ordered_samples;
+        struct list_head *head = &os->samples;
         struct sample_queue *tmp, *iter;
+        struct sample_data sample;
+        u64 limit = os->next_flush;
+        u64 last_ts = os->last_sample ? os->last_sample->timestamp : 0ULL;
 
         if (!ops->ordered_samples || !limit)
                 return;
 
         list_for_each_entry_safe(iter, tmp, head, list) {
                 if (iter->timestamp > limit)
-                        return;
+                        break;
 
-                if (iter == s->ordered_samples.last_inserted)
-                        s->ordered_samples.last_inserted = NULL;
+                event__parse_sample(iter->event, s, &sample);
+                perf_session_deliver_event(s, iter->event, &sample, ops,
+                                           iter->file_offset);
 
-                ops->sample((event_t *)iter->event, s);
-
-                s->ordered_samples.last_flush = iter->timestamp;
+                os->last_flush = iter->timestamp;
                 list_del(&iter->list);
-                free(iter->event);
-                free(iter);
+                list_add(&iter->list, &os->sample_cache);
+        }
+
+        if (list_empty(head)) {
+                os->last_sample = NULL;
+        } else if (last_ts <= limit) {
+                os->last_sample =
+                        list_entry(head->prev, struct sample_queue, list);
         }
 }
 
@@ -465,178 +560,265 @@ static int process_finished_round(event_t *event __used,
         return 0;
 }
 
-static void __queue_sample_end(struct sample_queue *new, struct list_head *head)
-{
-        struct sample_queue *iter;
-
-        list_for_each_entry_reverse(iter, head, list) {
-                if (iter->timestamp < new->timestamp) {
-                        list_add(&new->list, &iter->list);
-                        return;
-                }
-        }
-
-        list_add(&new->list, head);
-}
-
-static void __queue_sample_before(struct sample_queue *new,
-                                  struct sample_queue *iter,
-                                  struct list_head *head)
-{
-        list_for_each_entry_continue_reverse(iter, head, list) {
-                if (iter->timestamp < new->timestamp) {
-                        list_add(&new->list, &iter->list);
-                        return;
-                }
-        }
-
-        list_add(&new->list, head);
-}
-
-static void __queue_sample_after(struct sample_queue *new,
-                                 struct sample_queue *iter,
-                                 struct list_head *head)
-{
-        list_for_each_entry_continue(iter, head, list) {
-                if (iter->timestamp > new->timestamp) {
-                        list_add_tail(&new->list, &iter->list);
-                        return;
-                }
-        }
-        list_add_tail(&new->list, head);
-}
-
 /* The queue is ordered by time */
-static void __queue_sample_event(struct sample_queue *new,
-                                 struct perf_session *s)
+static void __queue_event(struct sample_queue *new, struct perf_session *s)
 {
-        struct sample_queue *last_inserted = s->ordered_samples.last_inserted;
-        struct list_head *head = &s->ordered_samples.samples_head;
+        struct ordered_samples *os = &s->ordered_samples;
+        struct sample_queue *sample = os->last_sample;
+        u64 timestamp = new->timestamp;
+        struct list_head *p;
 
+        os->last_sample = new;
 
-        if (!last_inserted) {
-                __queue_sample_end(new, head);
+        if (!sample) {
+                list_add(&new->list, &os->samples);
+                os->max_timestamp = timestamp;
                 return;
         }
 
         /*
-         * Most of the time the current event has a timestamp
-         * very close to the last event inserted, unless we just switched
-         * to another event buffer. Having a sorting based on a list and
-         * on the last inserted event that is close to the current one is
-         * probably more efficient than an rbtree based sorting.
+         * last_sample 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_inserted->timestamp >= new->timestamp)
-                __queue_sample_before(new, last_inserted, head);
-        else
-                __queue_sample_after(new, last_inserted, head);
+        if (sample->timestamp <= timestamp) {
+                while (sample->timestamp <= timestamp) {
+                        p = sample->list.next;
+                        if (p == &os->samples) {
+                                list_add_tail(&new->list, &os->samples);
+                                os->max_timestamp = timestamp;
+                                return;
+                        }
+                        sample = list_entry(p, struct sample_queue, list);
+                }
+                list_add_tail(&new->list, &sample->list);
+        } else {
+                while (sample->timestamp > timestamp) {
+                        p = sample->list.prev;
+                        if (p == &os->samples) {
+                                list_add(&new->list, &os->samples);
+                                return;
+                        }
+                        sample = list_entry(p, struct sample_queue, list);
+                }
+                list_add(&new->list, &sample->list);
+        }
 }
 
-static int queue_sample_event(event_t *event, struct sample_data *data,
-                              struct perf_session *s)
+#define MAX_SAMPLE_BUFFER       (64 * 1024 / sizeof(struct sample_queue))
+
+static int perf_session_queue_event(struct perf_session *s, event_t *event,
+                                    struct sample_data *data, u64 file_offset)
 {
+        struct ordered_samples *os = &s->ordered_samples;
+        struct list_head *sc = &os->sample_cache;
         u64 timestamp = data->time;
         struct sample_queue *new;
 
+        if (!timestamp || timestamp == ~0ULL)
+                return -ETIME;
 
         if (timestamp < s->ordered_samples.last_flush) {
                 printf("Warning: Timestamp below last timeslice flush\n");
                 return -EINVAL;
         }
 
-        new = malloc(sizeof(*new));
-        if (!new)
-                return -ENOMEM;
+        if (!list_empty(sc)) {
+                new = list_entry(sc->next, struct sample_queue, list);
+                list_del(&new->list);
+        } else if (os->sample_buffer) {
+                new = os->sample_buffer + os->sample_buffer_idx;
+                if (++os->sample_buffer_idx == MAX_SAMPLE_BUFFER)
+                        os->sample_buffer = NULL;
+        } else {
+                os->sample_buffer = malloc(MAX_SAMPLE_BUFFER * sizeof(*new));
+                if (!os->sample_buffer)
+                        return -ENOMEM;
+                list_add(&os->sample_buffer->list, &os->to_free);
+                os->sample_buffer_idx = 2;
+                new = os->sample_buffer + 1;
+        }
 
         new->timestamp = timestamp;
+        new->file_offset = file_offset;
+        new->event = event;
 
-        new->event = malloc(event->header.size);
-        if (!new->event) {
-                free(new);
-                return -ENOMEM;
-        }
+        __queue_event(new, s);
 
-        memcpy(new->event, event, event->header.size);
+        return 0;
+}
 
-        __queue_sample_event(new, s);
-        s->ordered_samples.last_inserted = new;
+static void callchain__printf(struct sample_data *sample)
+{
+        unsigned int i;
 
-        if (new->timestamp > s->ordered_samples.max_timestamp)
-                s->ordered_samples.max_timestamp = new->timestamp;
+        printf("... chain: nr:%Lu\n", sample->callchain->nr);
 
-        return 0;
+        for (i = 0; i < sample->callchain->nr; i++)
+                printf("..... %2d: %016Lx\n", i, sample->callchain->ips[i]);
 }
 
-static int perf_session__process_sample(event_t *event, struct perf_session *s,
-                                        struct perf_event_ops *ops)
+static void perf_session__print_tstamp(struct perf_session *session,
+                                       event_t *event,
+                                       struct sample_data *sample)
 {
-        struct sample_data data;
+        if (event->header.type != PERF_RECORD_SAMPLE &&
+            !session->sample_id_all) {
+                fputs("-1 -1 ", stdout);
+                return;
+        }
 
-        if (!ops->ordered_samples)
-                return ops->sample(event, s);
+        if ((session->sample_type & PERF_SAMPLE_CPU))
+                printf("%u ", sample->cpu);
 
-        bzero(&data, sizeof(struct sample_data));
-        event__parse_sample(event, s->sample_type, &data);
+        if (session->sample_type & PERF_SAMPLE_TIME)
+                printf("%Lu ", sample->time);
+}
 
-        queue_sample_event(event, &data, s);
+static void dump_event(struct perf_session *session, event_t *event,
+                       u64 file_offset, struct sample_data *sample)
+{
+        if (!dump_trace)
+                return;
 
-        return 0;
+        printf("\n%#Lx [%#x]: event: %d\n", file_offset, event->header.size,
+               event->header.type);
+
+        trace_event(event);
+
+        if (sample)
+                perf_session__print_tstamp(session, event, sample);
+
+        printf("%#Lx [%#x]: PERF_RECORD_%s", file_offset, event->header.size,
+               event__get_event_name(event->header.type));
 }
 
-static int perf_session__process_event(struct perf_session *self,
-                                       event_t *event,
-                                       struct perf_event_ops *ops,
-                                       u64 offset, u64 head)
+static void dump_sample(struct perf_session *session, event_t *event,
+                        struct sample_data *sample)
 {
-        trace_event(event);
+        if (!dump_trace)
+                return;
 
-        if (event->header.type < PERF_RECORD_HEADER_MAX) {
-                dump_printf("%#Lx [%#x]: PERF_RECORD_%s",
-                            offset + head, event->header.size,
-                            event__name[event->header.type]);
-                hists__inc_nr_events(&self->hists, event->header.type);
-        }
+        printf("(IP, %d): %d/%d: %#Lx period: %Ld\n", event->header.misc,
+               sample->pid, sample->tid, sample->ip, sample->period);
 
-        if (self->header.needs_swap && event__swap_ops[event->header.type])
-                event__swap_ops[event->header.type](event);
+        if (session->sample_type & PERF_SAMPLE_CALLCHAIN)
+                callchain__printf(sample);
+}
+
+static int perf_session_deliver_event(struct perf_session *session,
+                                      event_t *event,
+                                      struct sample_data *sample,
+                                      struct perf_event_ops *ops,
+                                      u64 file_offset)
+{
+        dump_event(session, event, file_offset, sample);
 
         switch (event->header.type) {
         case PERF_RECORD_SAMPLE:
-                return perf_session__process_sample(event, self, ops);
+                dump_sample(session, event, sample);
+                return ops->sample(event, sample, session);
         case PERF_RECORD_MMAP:
-                return ops->mmap(event, self);
+                return ops->mmap(event, sample, session);
         case PERF_RECORD_COMM:
-                return ops->comm(event, self);
+                return ops->comm(event, sample, session);
         case PERF_RECORD_FORK:
-                return ops->fork(event, self);
+                return ops->fork(event, sample, session);
         case PERF_RECORD_EXIT:
-                return ops->exit(event, self);
+                return ops->exit(event, sample, session);
         case PERF_RECORD_LOST:
-                return ops->lost(event, self);
+                return ops->lost(event, sample, session);
         case PERF_RECORD_READ:
-                return ops->read(event, self);
+                return ops->read(event, sample, session);
         case PERF_RECORD_THROTTLE:
-                return ops->throttle(event, self);
+                return ops->throttle(event, sample, session);
         case PERF_RECORD_UNTHROTTLE:
-                return ops->unthrottle(event, self);
+                return ops->unthrottle(event, sample, session);
+        default:
+                ++session->hists.stats.nr_unknown_events;
+                return -1;
+        }
+}
+
+static int perf_session__preprocess_sample(struct perf_session *session,
+                                           event_t *event, struct sample_data *sample)
+{
+        if (event->header.type != PERF_RECORD_SAMPLE ||
+            !(session->sample_type & PERF_SAMPLE_CALLCHAIN))
+                return 0;
+
+        if (!ip_callchain__valid(sample->callchain, event)) {
+                pr_debug("call-chain problem with event, skipping it.\n");
+                ++session->hists.stats.nr_invalid_chains;
+                session->hists.stats.total_invalid_chains += sample->period;
+                return -EINVAL;
+        }
+        return 0;
+}
+
+static int perf_session__process_user_event(struct perf_session *session, event_t *event,
+                                            struct perf_event_ops *ops, u64 file_offset)
+{
+        dump_event(session, event, file_offset, NULL);
+
+        /* These events are processed right away */
+        switch (event->header.type) {
         case PERF_RECORD_HEADER_ATTR:
-                return ops->attr(event, self);
+                return ops->attr(event, session);
         case PERF_RECORD_HEADER_EVENT_TYPE:
-                return ops->event_type(event, self);
+                return ops->event_type(event, session);
         case PERF_RECORD_HEADER_TRACING_DATA:
                 /* setup for reading amidst mmap */
-                lseek(self->fd, offset + head, SEEK_SET);
-                return ops->tracing_data(event, self);
+                lseek(session->fd, file_offset, SEEK_SET);
+                return ops->tracing_data(event, session);
         case PERF_RECORD_HEADER_BUILD_ID:
-                return ops->build_id(event, self);
+                return ops->build_id(event, session);
         case PERF_RECORD_FINISHED_ROUND:
-                return ops->finished_round(event, self, ops);
+                return ops->finished_round(event, session, ops);
         default:
-                ++self->hists.stats.nr_unknown_events;
-                return -1;
+                return -EINVAL;
         }
 }
 
+static int perf_session__process_event(struct perf_session *session,
+                                       event_t *event,
+                                       struct perf_event_ops *ops,
+                                       u64 file_offset)
+{
+        struct sample_data sample;
+        int ret;
+
+        if (session->header.needs_swap && event__swap_ops[event->header.type])
+                event__swap_ops[event->header.type](event);
+
+        if (event->header.type >= PERF_RECORD_HEADER_MAX)
+                return -EINVAL;
+
+        hists__inc_nr_events(&session->hists, event->header.type);
+
+        if (event->header.type >= PERF_RECORD_USER_TYPE_START)
+                return perf_session__process_user_event(session, event, ops, file_offset);
+
+        /*
+         * For all kernel events we get the sample data
+         */
+        event__parse_sample(event, session, &sample);
+
+        /* Preprocess sample records - precheck callchains */
+        if (perf_session__preprocess_sample(session, event, &sample))
+                return 0;
+
+        if (ops->ordered_samples) {
+                ret = perf_session_queue_event(session, event, &sample,
+                                               file_offset);
+                if (ret != -ETIME)
+                        return ret;
+        }
+
+        return perf_session_deliver_event(session, event, &sample, ops,
+                                          file_offset);
+}
+
 void perf_event_header__bswap(struct perf_event_header *self)
 {
         self->type = bswap_32(self->type);
@@ -656,21 +838,33 @@ static struct thread *perf_session__register_idle_thread(struct perf_session *se
         return thread;
 }
 
-int do_read(int fd, void *buf, size_t size)
+static void perf_session__warn_about_errors(const struct perf_session *session,
+                                            const struct perf_event_ops *ops)
 {
-        void *buf_start = buf;
-
-        while (size) {
-                int ret = read(fd, buf, size);
-
-                if (ret <= 0)
-                        return ret;
+        if (ops->lost == event__process_lost &&
+            session->hists.stats.total_lost != 0) {
+                ui__warning("Processed %Lu events and LOST %Lu!\n\n"
+                            "Check IO/CPU overload!\n\n",
+                            session->hists.stats.total_period,
+                            session->hists.stats.total_lost);
+        }
 
-                size -= ret;
-                buf += ret;
+        if (session->hists.stats.nr_unknown_events != 0) {
+                ui__warning("Found %u unknown events!\n\n"
+                            "Is this an older tool processing a perf.data "
+                            "file generated by a more recent tool?\n\n"
+                            "If that is not the case, consider "
+                            "reporting to linux-kernel@vger.kernel.org.\n\n",
+                            session->hists.stats.nr_unknown_events);
         }
 
-        return buf - buf_start;
+        if (session->hists.stats.nr_invalid_chains != 0) {
+                ui__warning("Found invalid callchains!\n\n"
+                            "%u out of %u events were discarded for this reason.\n\n"
+                            "Consider reporting to linux-kernel@vger.kernel.org.\n\n",
+                            session->hists.stats.nr_invalid_chains,
+                            session->hists.stats.nr_events[PERF_RECORD_SAMPLE]);
+        }
 }
 
 #define session_done()  (*(volatile int *)(&session_done))
@@ -690,7 +884,7 @@ static int __perf_session__process_pipe_events(struct perf_session *self,
 
         head = 0;
 more:
-        err = do_read(self->fd, &event, sizeof(struct perf_event_header));
+        err = readn(self->fd, &event, sizeof(struct perf_event_header));
         if (err <= 0) {
                 if (err == 0)
                         goto done;
@@ -710,8 +904,7 @@ more:
         p += sizeof(struct perf_event_header);
 
         if (size - sizeof(struct perf_event_header)) {
-                err = do_read(self->fd, p,
-                              size - sizeof(struct perf_event_header));
+                err = readn(self->fd, p, size - sizeof(struct perf_event_header));
                 if (err <= 0) {
                         if (err == 0) {
                                 pr_err("unexpected end of event stream\n");
@@ -724,8 +917,7 @@ more:
         }
 
         if (size == 0 ||
-            (skip = perf_session__process_event(self, &event, ops,
-                                                0, head)) < 0) {
+            (skip = perf_session__process_event(self, &event, ops, head)) < 0) {
                 dump_printf("%#Lx [%#x]: skipping unknown header type: %d\n",
                             head, event.header.size, event.header.type);
                 /*
@@ -740,9 +932,6 @@ more:
 
         head += size;
 
-        dump_printf("\n%#Lx [%#x]: event: %d\n",
-                    head, event.header.size, event.header.type);
-
         if (skip > 0)
                 head += skip;
 
@@ -751,82 +940,91 @@ more:
 done:
         err = 0;
 out_err:
+        perf_session__warn_about_errors(self, ops);
+        perf_session_free_sample_buffers(self);
         return err;
 }
 
-int __perf_session__process_events(struct perf_session *self,
+int __perf_session__process_events(struct perf_session *session,
                                    u64 data_offset, u64 data_size,
                                    u64 file_size, struct perf_event_ops *ops)
 {
-        int err, mmap_prot, mmap_flags;
-        u64 head, shift;
-        u64 offset = 0;
-        size_t  page_size;
+        u64 head, page_offset, file_offset, file_pos, progress_next;
+        int err, mmap_prot, mmap_flags, map_idx = 0;
+        struct ui_progress *progress;
+        size_t  page_size, mmap_size;
+        char *buf, *mmaps[8];
         event_t *event;
         uint32_t size;
-        char *buf;
-        struct ui_progress *progress = ui_progress__new("Processing events...",
-                                                        self->size);
-        if (progress == NULL)
-                return -1;
 
         perf_event_ops__fill_defaults(ops);
 
         page_size = sysconf(_SC_PAGESIZE);
 
-        head = data_offset;
-        shift = page_size * (head / page_size);
-        offset += shift;
-        head -= shift;
+        page_offset = page_size * (data_offset / page_size);
+        file_offset = page_offset;
+        head = data_offset - page_offset;
+
+        if (data_offset + data_size < file_size)
+                file_size = data_offset + data_size;
+
+        progress_next = file_size / 16;
+        progress = ui_progress__new("Processing events...", file_size);
+        if (progress == NULL)
+                return -1;
+
+        mmap_size = session->mmap_window;
+        if (mmap_size > file_size)
+                mmap_size = file_size;
+
+        memset(mmaps, 0, sizeof(mmaps));
 
         mmap_prot  = PROT_READ;
         mmap_flags = MAP_SHARED;
 
-        if (self->header.needs_swap) {
+        if (session->header.needs_swap) {
                 mmap_prot  |= PROT_WRITE;
                 mmap_flags = MAP_PRIVATE;
         }
 remap:
-        buf = mmap(NULL, page_size * self->mmap_window, mmap_prot,
-                   mmap_flags, self->fd, offset);
+        buf = mmap(NULL, mmap_size, mmap_prot, mmap_flags, session->fd,
+                   file_offset);
         if (buf == MAP_FAILED) {
                 pr_err("failed to mmap file\n");
                 err = -errno;
                 goto out_err;
         }
+        mmaps[map_idx] = buf;
+        map_idx = (map_idx + 1) & (ARRAY_SIZE(mmaps) - 1);
+        file_pos = file_offset + head;
 
 more:
         event = (event_t *)(buf + head);
-        ui_progress__update(progress, offset);
 
-        if (self->header.needs_swap)
+        if (session->header.needs_swap)
                 perf_event_header__bswap(&event->header);
         size = event->header.size;
         if (size == 0)
                 size = 8;
 
-        if (head + event->header.size >= page_size * self->mmap_window) {
-                int munmap_ret;
-
-                shift = page_size * (head / page_size);
-
-                munmap_ret = munmap(buf, page_size * self->mmap_window);
-                assert(munmap_ret == 0);
+        if (head + event->header.size >= mmap_size) {
+                if (mmaps[map_idx]) {
+                        munmap(mmaps[map_idx], mmap_size);
+                        mmaps[map_idx] = NULL;
+                }
 
-                offset += shift;
-                head -= shift;
+                page_offset = page_size * (head / page_size);
+                file_offset += page_offset;
+                head -= page_offset;
                 goto remap;
         }
 
         size = event->header.size;
 
-        dump_printf("\n%#Lx [%#x]: event: %d\n",
-                    offset + head, event->header.size, event->header.type);
-
         if (size == 0 ||
-            perf_session__process_event(self, event, ops, offset, head) < 0) {
+            perf_session__process_event(session, event, ops, file_pos) < 0) {
                 dump_printf("%#Lx [%#x]: skipping unknown header type: %d\n",
-                            offset + head, event->header.size,
+                            file_offset + head, event->header.size,
                             event->header.type);
                 /*
                  * assume we lost track of the stream, check alignment, and
@@ -839,19 +1037,24 @@ more:
         }
 
         head += size;
+        file_pos += size;
 
-        if (offset + head >= data_offset + data_size)
-                goto done;
+        if (file_pos >= progress_next) {
+                progress_next += file_size / 16;
+                ui_progress__update(progress, file_pos);
+        }
 
-        if (offset + head < file_size)
+        if (file_pos < file_size)
                 goto more;
-done:
+
         err = 0;
         /* do the final flush for ordered samples */
-        self->ordered_samples.next_flush = ULLONG_MAX;
-        flush_sample_queue(self, ops);
+        session->ordered_samples.next_flush = ULLONG_MAX;
+        flush_sample_queue(session, ops);
 out_err:
         ui_progress__delete(progress);
+        perf_session__warn_about_errors(session, ops);
+        perf_session_free_sample_buffers(session);
         return err;
 }