perf session: Use sensible mmap size

[mirror_ubuntu-artful-kernel.git] / tools / perf / util / session.c

#define _FILE_OFFSET_BITS 64

#include <linux/kernel.h>

#include <byteswap.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/mman.h>

#include "session.h"
#include "sort.h"
#include "util.h"

static int perf_session__open(struct perf_session *self, bool force)
{
        struct stat input_stat;

        if (!strcmp(self->filename, "-")) {
                self->fd_pipe = true;
                self->fd = STDIN_FILENO;

                if (perf_header__read(self, self->fd) < 0)
                        pr_err("incompatible file format");

                return 0;
        }

        self->fd = open(self->filename, O_RDONLY);
        if (self->fd < 0) {
                int err = errno;

                pr_err("failed to open %s: %s", self->filename, strerror(err));
                if (err == ENOENT && !strcmp(self->filename, "perf.data"))
                        pr_err("  (try 'perf record' first)");
                pr_err("\n");
                return -errno;
        }

        if (fstat(self->fd, &input_stat) < 0)
                goto out_close;

        if (!force && input_stat.st_uid && (input_stat.st_uid != geteuid())) {
                pr_err("file %s not owned by current user or root\n",
                       self->filename);
                goto out_close;
        }

        if (!input_stat.st_size) {
                pr_info("zero-sized file (%s), nothing to do!\n",
                        self->filename);
                goto out_close;
        }

        if (perf_header__read(self, self->fd) < 0) {
                pr_err("incompatible file format");
                goto out_close;
        }

        self->size = input_stat.st_size;
        return 0;

out_close:
        close(self->fd);
        self->fd = -1;
        return -1;
}

void perf_session__update_sample_type(struct perf_session *self)
{
        self->sample_type = perf_header__sample_type(&self->header);
}

int perf_session__create_kernel_maps(struct perf_session *self)
{
        int ret = machine__create_kernel_maps(&self->host_machine);

        if (ret >= 0)
                ret = machines__create_guest_kernel_maps(&self->machines);
        return ret;
}

static void perf_session__destroy_kernel_maps(struct perf_session *self)
{
        machine__destroy_kernel_maps(&self->host_machine);
        machines__destroy_guest_kernel_maps(&self->machines);
}

struct perf_session *perf_session__new(const char *filename, int mode, bool force, bool repipe)
{
        size_t len = filename ? strlen(filename) + 1 : 0;
        struct perf_session *self = zalloc(sizeof(*self) + len);

        if (self == NULL)
                goto out;

        if (perf_header__init(&self->header) < 0)
                goto out_free;

        memcpy(self->filename, filename, len);
        self->threads = RB_ROOT;
        INIT_LIST_HEAD(&self->dead_threads);
        self->hists_tree = RB_ROOT;
        self->last_match = NULL;
        /*
         * 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);
        machine__init(&self->host_machine, "", HOST_KERNEL_ID);

        if (mode == O_RDONLY) {
                if (perf_session__open(self, force) < 0)
                        goto out_delete;
        } else if (mode == O_WRONLY) {
                /*
                 * In O_RDONLY mode this will be performed when reading the
                 * kernel MMAP event, in event__process_mmap().
                 */
                if (perf_session__create_kernel_maps(self) < 0)
                        goto out_delete;
        }

        perf_session__update_sample_type(self);
out:
        return self;
out_free:
        free(self);
        return NULL;
out_delete:
        perf_session__delete(self);
        return NULL;
}

static void perf_session__delete_dead_threads(struct perf_session *self)
{
        struct thread *n, *t;

        list_for_each_entry_safe(t, n, &self->dead_threads, node) {
                list_del(&t->node);
                thread__delete(t);
        }
}

static void perf_session__delete_threads(struct perf_session *self)
{
        struct rb_node *nd = rb_first(&self->threads);

        while (nd) {
                struct thread *t = rb_entry(nd, struct thread, rb_node);

                rb_erase(&t->rb_node, &self->threads);
                nd = rb_next(nd);
                thread__delete(t);
        }
}

void perf_session__delete(struct perf_session *self)
{
        perf_header__exit(&self->header);
        perf_session__destroy_kernel_maps(self);
        perf_session__delete_dead_threads(self);
        perf_session__delete_threads(self);
        machine__exit(&self->host_machine);
        close(self->fd);
        free(self);
}

void perf_session__remove_thread(struct perf_session *self, struct thread *th)
{
        self->last_match = NULL;
        rb_erase(&th->rb_node, &self->threads);
        /*
         * We may have references to this thread, for instance in some hist_entry
         * instances, so just move them to a separate list.
         */
        list_add_tail(&th->node, &self->dead_threads);
}

static bool symbol__match_parent_regex(struct symbol *sym)
{
        if (sym->name && !regexec(&parent_regex, sym->name, 0, NULL, 0))
                return 1;

        return 0;
}

struct map_symbol *perf_session__resolve_callchain(struct perf_session *self,
                                                   struct thread *thread,
                                                   struct ip_callchain *chain,
                                                   struct symbol **parent)
{
        u8 cpumode = PERF_RECORD_MISC_USER;
        unsigned int i;
        struct map_symbol *syms = calloc(chain->nr, sizeof(*syms));

        if (!syms)
                return NULL;

        for (i = 0; i < chain->nr; i++) {
                u64 ip = chain->ips[i];
                struct addr_location al;

                if (ip >= PERF_CONTEXT_MAX) {
                        switch (ip) {
                        case PERF_CONTEXT_HV:
                                cpumode = PERF_RECORD_MISC_HYPERVISOR;  break;
                        case PERF_CONTEXT_KERNEL:
                                cpumode = PERF_RECORD_MISC_KERNEL;      break;
                        case PERF_CONTEXT_USER:
                                cpumode = PERF_RECORD_MISC_USER;        break;
                        default:
                                break;
                        }
                        continue;
                }

                al.filtered = false;
                thread__find_addr_location(thread, self, cpumode,
                                MAP__FUNCTION, thread->pid, ip, &al, NULL);
                if (al.sym != NULL) {
                        if (sort__has_parent && !*parent &&
                            symbol__match_parent_regex(al.sym))
                                *parent = al.sym;
                        if (!symbol_conf.use_callchain)
                                break;
                        syms[i].map = al.map;
                        syms[i].sym = al.sym;
                }
        }

        return syms;
}

static int process_event_stub(event_t *event __used,
                              struct perf_session *session __used)
{
        dump_printf(": unhandled!\n");
        return 0;
}

static int process_finished_round_stub(event_t *event __used,
                                       struct perf_session *session __used,
                                       struct perf_event_ops *ops __used)
{
        dump_printf(": unhandled!\n");
        return 0;
}

static int process_finished_round(event_t *event,
                                  struct perf_session *session,
                                  struct perf_event_ops *ops);

static void perf_event_ops__fill_defaults(struct perf_event_ops *handler)
{
        if (handler->sample == NULL)
                handler->sample = process_event_stub;
        if (handler->mmap == NULL)
                handler->mmap = process_event_stub;
        if (handler->comm == NULL)
                handler->comm = process_event_stub;
        if (handler->fork == NULL)
                handler->fork = process_event_stub;
        if (handler->exit == NULL)
                handler->exit = process_event_stub;
        if (handler->lost == NULL)
                handler->lost = event__process_lost;
        if (handler->read == NULL)
                handler->read = process_event_stub;
        if (handler->throttle == NULL)
                handler->throttle = process_event_stub;
        if (handler->unthrottle == NULL)
                handler->unthrottle = process_event_stub;
        if (handler->attr == NULL)
                handler->attr = process_event_stub;
        if (handler->event_type == NULL)
                handler->event_type = process_event_stub;
        if (handler->tracing_data == NULL)
                handler->tracing_data = process_event_stub;
        if (handler->build_id == NULL)
                handler->build_id = process_event_stub;
        if (handler->finished_round == NULL) {
                if (handler->ordered_samples)
                        handler->finished_round = process_finished_round;
                else
                        handler->finished_round = process_finished_round_stub;
        }
}

void mem_bswap_64(void *src, int byte_size)
{
        u64 *m = src;

        while (byte_size > 0) {
                *m = bswap_64(*m);
                byte_size -= sizeof(u64);
                ++m;
        }
}

static void event__all64_swap(event_t *self)
{
        struct perf_event_header *hdr = &self->header;
        mem_bswap_64(hdr + 1, self->header.size - sizeof(*hdr));
}

static void event__comm_swap(event_t *self)
{
        self->comm.pid = bswap_32(self->comm.pid);
        self->comm.tid = bswap_32(self->comm.tid);
}

static void event__mmap_swap(event_t *self)
{
        self->mmap.pid   = bswap_32(self->mmap.pid);
        self->mmap.tid   = bswap_32(self->mmap.tid);
        self->mmap.start = bswap_64(self->mmap.start);
        self->mmap.len   = bswap_64(self->mmap.len);
        self->mmap.pgoff = bswap_64(self->mmap.pgoff);
}

static void event__task_swap(event_t *self)
{
        self->fork.pid  = bswap_32(self->fork.pid);
        self->fork.tid  = bswap_32(self->fork.tid);
        self->fork.ppid = bswap_32(self->fork.ppid);
        self->fork.ptid = bswap_32(self->fork.ptid);
        self->fork.time = bswap_64(self->fork.time);
}

static void event__read_swap(event_t *self)
{
        self->read.pid          = bswap_32(self->read.pid);
        self->read.tid          = bswap_32(self->read.tid);
        self->read.value        = bswap_64(self->read.value);
        self->read.time_enabled = bswap_64(self->read.time_enabled);
        self->read.time_running = bswap_64(self->read.time_running);
        self->read.id           = bswap_64(self->read.id);
}

static void event__attr_swap(event_t *self)
{
        size_t size;

        self->attr.attr.type            = bswap_32(self->attr.attr.type);
        self->attr.attr.size            = bswap_32(self->attr.attr.size);
        self->attr.attr.config          = bswap_64(self->attr.attr.config);
        self->attr.attr.sample_period   = bswap_64(self->attr.attr.sample_period);
        self->attr.attr.sample_type     = bswap_64(self->attr.attr.sample_type);
        self->attr.attr.read_format     = bswap_64(self->attr.attr.read_format);
        self->attr.attr.wakeup_events   = bswap_32(self->attr.attr.wakeup_events);
        self->attr.attr.bp_type         = bswap_32(self->attr.attr.bp_type);
        self->attr.attr.bp_addr         = bswap_64(self->attr.attr.bp_addr);
        self->attr.attr.bp_len          = bswap_64(self->attr.attr.bp_len);

        size = self->header.size;
        size -= (void *)&self->attr.id - (void *)self;
        mem_bswap_64(self->attr.id, size);
}

static void event__event_type_swap(event_t *self)
{
        self->event_type.event_type.event_id =
                bswap_64(self->event_type.event_type.event_id);
}

static void event__tracing_data_swap(event_t *self)
{
        self->tracing_data.size = bswap_32(self->tracing_data.size);
}

typedef void (*event__swap_op)(event_t *self);

static event__swap_op event__swap_ops[] = {
        [PERF_RECORD_MMAP]   = event__mmap_swap,
        [PERF_RECORD_COMM]   = event__comm_swap,
        [PERF_RECORD_FORK]   = event__task_swap,
        [PERF_RECORD_EXIT]   = event__task_swap,
        [PERF_RECORD_LOST]   = event__all64_swap,
        [PERF_RECORD_READ]   = event__read_swap,
        [PERF_RECORD_SAMPLE] = event__all64_swap,
        [PERF_RECORD_HEADER_ATTR]   = event__attr_swap,
        [PERF_RECORD_HEADER_EVENT_TYPE]   = event__event_type_swap,
        [PERF_RECORD_HEADER_TRACING_DATA]   = event__tracing_data_swap,
        [PERF_RECORD_HEADER_BUILD_ID]   = NULL,
        [PERF_RECORD_HEADER_MAX]    = NULL,
};

struct sample_queue {
        u64                     timestamp;
        event_t                 *event;
        struct list_head        list;
};

static void flush_sample_queue(struct perf_session *s,
                               struct perf_event_ops *ops)
{
        struct ordered_samples *os = &s->ordered_samples;
        struct list_head *head = &os->samples;
        struct sample_queue *tmp, *iter;
        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)
                        break;

                ops->sample(iter->event, s);

                os->last_flush = iter->timestamp;
                list_del(&iter->list);
                free(iter->event);
                free(iter);
        }

        if (list_empty(head)) {
                os->last_sample = NULL;
        } else if (last_ts <= limit) {
                os->last_sample =
                        list_entry(head->prev, struct sample_queue, list);
        }
}

/*
 * When perf record finishes a pass on every buffers, it records this pseudo
 * event.
 * We record the max timestamp t found in the pass n.
 * Assuming these timestamps are monotonic across cpus, we know that if
 * a buffer still has events with timestamps below t, they will be all
 * available and then read in the pass n + 1.
 * Hence when we start to read the pass n + 2, we can safely flush every
 * events with timestamps below t.
 *
 *    ============ PASS n =================
 *       CPU 0         |   CPU 1
 *                     |
 *    cnt1 timestamps  |   cnt2 timestamps
 *          1          |         2
 *          2          |         3
 *          -          |         4  <--- max recorded
 *
 *    ============ PASS n + 1 ==============
 *       CPU 0         |   CPU 1
 *                     |
 *    cnt1 timestamps  |   cnt2 timestamps
 *          3          |         5
 *          4          |         6
 *          5          |         7 <---- max recorded
 *
 *      Flush every events below timestamp 4
 *
 *    ============ PASS n + 2 ==============
 *       CPU 0         |   CPU 1
 *                     |
 *    cnt1 timestamps  |   cnt2 timestamps
 *          6          |         8
 *          7          |         9
 *          -          |         10
 *
 *      Flush every events below timestamp 7
 *      etc...
 */
static int process_finished_round(event_t *event __used,
                                  struct perf_session *session,
                                  struct perf_event_ops *ops)
{
        flush_sample_queue(session, ops);
        session->ordered_samples.next_flush = session->ordered_samples.max_timestamp;

        return 0;
}

/* The queue is ordered by time */
static void __queue_sample_event(struct sample_queue *new,
                                 struct perf_session *s)
{
        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 (!sample) {
                list_add(&new->list, &os->samples);
                os->max_timestamp = timestamp;
                return;
        }

        /*
         * 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 (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)
{
        u64 timestamp = data->time;
        struct sample_queue *new;


        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;

        new->timestamp = timestamp;

        new->event = malloc(event->header.size);
        if (!new->event) {
                free(new);
                return -ENOMEM;
        }

        memcpy(new->event, event, event->header.size);

        __queue_sample_event(new, s);

        return 0;
}

static int perf_session__process_sample(event_t *event, struct perf_session *s,
                                        struct perf_event_ops *ops)
{
        struct sample_data data;

        if (!ops->ordered_samples)
                return ops->sample(event, s);

        bzero(&data, sizeof(struct sample_data));
        event__parse_sample(event, s->sample_type, &data);

        queue_sample_event(event, &data, s);

        return 0;
}

static int perf_session__process_event(struct perf_session *self,
                                       event_t *event,
                                       struct perf_event_ops *ops,
                                       u64 file_offset)
{
        trace_event(event);

        if (event->header.type < PERF_RECORD_HEADER_MAX) {
                dump_printf("%#Lx [%#x]: PERF_RECORD_%s",
                            file_offset, event->header.size,
                            event__name[event->header.type]);
                hists__inc_nr_events(&self->hists, event->header.type);
        }

        if (self->header.needs_swap && event__swap_ops[event->header.type])
                event__swap_ops[event->header.type](event);

        switch (event->header.type) {
        case PERF_RECORD_SAMPLE:
                return perf_session__process_sample(event, self, ops);
        case PERF_RECORD_MMAP:
                return ops->mmap(event, self);
        case PERF_RECORD_COMM:
                return ops->comm(event, self);
        case PERF_RECORD_FORK:
                return ops->fork(event, self);
        case PERF_RECORD_EXIT:
                return ops->exit(event, self);
        case PERF_RECORD_LOST:
                return ops->lost(event, self);
        case PERF_RECORD_READ:
                return ops->read(event, self);
        case PERF_RECORD_THROTTLE:
                return ops->throttle(event, self);
        case PERF_RECORD_UNTHROTTLE:
                return ops->unthrottle(event, self);
        case PERF_RECORD_HEADER_ATTR:
                return ops->attr(event, self);
        case PERF_RECORD_HEADER_EVENT_TYPE:
                return ops->event_type(event, self);
        case PERF_RECORD_HEADER_TRACING_DATA:
                /* setup for reading amidst mmap */
                lseek(self->fd, file_offset, SEEK_SET);
                return ops->tracing_data(event, self);
        case PERF_RECORD_HEADER_BUILD_ID:
                return ops->build_id(event, self);
        case PERF_RECORD_FINISHED_ROUND:
                return ops->finished_round(event, self, ops);
        default:
                ++self->hists.stats.nr_unknown_events;
                return -1;
        }
}

void perf_event_header__bswap(struct perf_event_header *self)
{
        self->type = bswap_32(self->type);
        self->misc = bswap_16(self->misc);
        self->size = bswap_16(self->size);
}

static struct thread *perf_session__register_idle_thread(struct perf_session *self)
{
        struct thread *thread = perf_session__findnew(self, 0);

        if (thread == NULL || thread__set_comm(thread, "swapper")) {
                pr_err("problem inserting idle task.\n");
                thread = NULL;
        }

        return thread;
}

int do_read(int fd, void *buf, size_t size)
{
        void *buf_start = buf;

        while (size) {
                int ret = read(fd, buf, size);

                if (ret <= 0)
                        return ret;

                size -= ret;
                buf += ret;
        }

        return buf - buf_start;
}

#define session_done()  (*(volatile int *)(&session_done))
volatile int session_done;

static int __perf_session__process_pipe_events(struct perf_session *self,
                                               struct perf_event_ops *ops)
{
        event_t event;
        uint32_t size;
        int skip = 0;
        u64 head;
        int err;
        void *p;

        perf_event_ops__fill_defaults(ops);

        head = 0;
more:
        err = do_read(self->fd, &event, sizeof(struct perf_event_header));
        if (err <= 0) {
                if (err == 0)
                        goto done;

                pr_err("failed to read event header\n");
                goto out_err;
        }

        if (self->header.needs_swap)
                perf_event_header__bswap(&event.header);

        size = event.header.size;
        if (size == 0)
                size = 8;

        p = &event;
        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));
                if (err <= 0) {
                        if (err == 0) {
                                pr_err("unexpected end of event stream\n");
                                goto done;
                        }

                        pr_err("failed to read event data\n");
                        goto out_err;
                }
        }

        if (size == 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);
                /*
                 * assume we lost track of the stream, check alignment, and
                 * increment a single u64 in the hope to catch on again 'soon'.
                 */
                if (unlikely(head & 7))
                        head &= ~7ULL;

                size = 8;
        }

        head += size;

        dump_printf("\n%#Lx [%#x]: event: %d\n",
                    head, event.header.size, event.header.type);

        if (skip > 0)
                head += skip;

        if (!session_done())
                goto more;
done:
        err = 0;
out_err:
        return err;
}

int __perf_session__process_events(struct perf_session *session,
                                   u64 data_offset, u64 data_size,
                                   u64 file_size, struct perf_event_ops *ops)
{
        u64 head, page_offset, file_offset, file_pos, progress_next;
        int err, mmap_prot, mmap_flags;
        struct ui_progress *progress;
        size_t  page_size, mmap_size;
        event_t *event;
        uint32_t size;
        char *buf;

        perf_event_ops__fill_defaults(ops);

        page_size = sysconf(_SC_PAGESIZE);

        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;

        mmap_prot  = PROT_READ;
        mmap_flags = MAP_SHARED;

        if (session->header.needs_swap) {
                mmap_prot  |= PROT_WRITE;
                mmap_flags = MAP_PRIVATE;
        }
remap:
        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;
        }
        file_pos = file_offset + head;

more:
        event = (event_t *)(buf + head);

        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 >= mmap_size) {
                int munmap_ret;

                munmap_ret = munmap(buf, mmap_size);
                assert(munmap_ret == 0);

                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",
                    file_pos, event->header.size, event->header.type);

        if (size == 0 ||
            perf_session__process_event(session, event, ops, file_pos) < 0) {
                dump_printf("%#Lx [%#x]: skipping unknown header type: %d\n",
                            file_offset + head, event->header.size,
                            event->header.type);
                /*
                 * assume we lost track of the stream, check alignment, and
                 * increment a single u64 in the hope to catch on again 'soon'.
                 */
                if (unlikely(head & 7))
                        head &= ~7ULL;

                size = 8;
        }

        head += size;
        file_pos += size;

        if (file_pos >= progress_next) {
                progress_next += file_size / 16;
                ui_progress__update(progress, file_pos);
        }

        if (file_pos < file_size)
                goto more;

        err = 0;
        /* do the final flush for ordered samples */
        session->ordered_samples.next_flush = ULLONG_MAX;
        flush_sample_queue(session, ops);
out_err:
        ui_progress__delete(progress);

        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);
        }

        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 err;
}

int perf_session__process_events(struct perf_session *self,
                                 struct perf_event_ops *ops)
{
        int err;

        if (perf_session__register_idle_thread(self) == NULL)
                return -ENOMEM;

        if (!self->fd_pipe)
                err = __perf_session__process_events(self,
                                                     self->header.data_offset,
                                                     self->header.data_size,
                                                     self->size, ops);
        else
                err = __perf_session__process_pipe_events(self, ops);

        return err;
}

bool perf_session__has_traces(struct perf_session *self, const char *msg)
{
        if (!(self->sample_type & PERF_SAMPLE_RAW)) {
                pr_err("No trace sample to read. Did you call 'perf %s'?\n", msg);
                return false;
        }

        return true;
}

int perf_session__set_kallsyms_ref_reloc_sym(struct map **maps,
                                             const char *symbol_name,
                                             u64 addr)
{
        char *bracket;
        enum map_type i;
        struct ref_reloc_sym *ref;

        ref = zalloc(sizeof(struct ref_reloc_sym));
        if (ref == NULL)
                return -ENOMEM;

        ref->name = strdup(symbol_name);
        if (ref->name == NULL) {
                free(ref);
                return -ENOMEM;
        }

        bracket = strchr(ref->name, ']');
        if (bracket)
                *bracket = '\0';

        ref->addr = addr;

        for (i = 0; i < MAP__NR_TYPES; ++i) {
                struct kmap *kmap = map__kmap(maps[i]);
                kmap->ref_reloc_sym = ref;
        }

        return 0;
}

size_t perf_session__fprintf_dsos(struct perf_session *self, FILE *fp)
{
        return __dsos__fprintf(&self->host_machine.kernel_dsos, fp) +
               __dsos__fprintf(&self->host_machine.user_dsos, fp) +
               machines__fprintf_dsos(&self->machines, fp);
}

size_t perf_session__fprintf_dsos_buildid(struct perf_session *self, FILE *fp,
                                          bool with_hits)
{
        size_t ret = machine__fprintf_dsos_buildid(&self->host_machine, fp, with_hits);
        return ret + machines__fprintf_dsos_buildid(&self->machines, fp, with_hits);
}