Merge branches 'acpi_pad', 'acpica', 'apei-bugzilla-43282', 'battery', 'cpuidle-coupl...

[GitHub/mt8127/android_kernel_alcatel_ttab.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 "evlist.h"
#include "evsel.h"
#include "session.h"
#include "tool.h"
#include "sort.h"
#include "util.h"
#include "cpumap.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_session__read_header(self, self->fd) < 0)
                        pr_err("incompatible file format (rerun with -v to learn more)");

                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_session__read_header(self, self->fd) < 0) {
                pr_err("incompatible file format (rerun with -v to learn more)");
                goto out_close;
        }

        if (!perf_evlist__valid_sample_type(self->evlist)) {
                pr_err("non matching sample_type");
                goto out_close;
        }

        if (!perf_evlist__valid_sample_id_all(self->evlist)) {
                pr_err("non matching sample_id_all");
                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_evlist__sample_type(self->evlist);
        self->sample_size = __perf_evsel__sample_size(self->sample_type);
        self->sample_id_all = perf_evlist__sample_id_all(self->evlist);
        self->id_hdr_size = perf_evlist__id_hdr_size(self->evlist);
        self->host_machine.id_hdr_size = self->id_hdr_size;
}

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,
                                       struct perf_tool *tool)
{
        struct perf_session *self;
        struct stat st;
        size_t len;

        if (!filename || !strlen(filename)) {
                if (!fstat(STDIN_FILENO, &st) && S_ISFIFO(st.st_mode))
                        filename = "-";
                else
                        filename = "perf.data";
        }

        len = strlen(filename);
        self = zalloc(sizeof(*self) + len);

        if (self == NULL)
                goto out;

        memcpy(self->filename, filename, len);
        /*
         * 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);
        INIT_LIST_HEAD(&self->ordered_samples.sample_cache);
        INIT_LIST_HEAD(&self->ordered_samples.to_free);
        machine__init(&self->host_machine, "", HOST_KERNEL_ID);
        hists__init(&self->hists);

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

        if (tool && tool->ordering_requires_timestamps &&
            tool->ordered_samples && !self->sample_id_all) {
                dump_printf("WARNING: No sample_id_all support, falling back to unordered processing\n");
                tool->ordered_samples = false;
        }

out:
        return self;
out_delete:
        perf_session__delete(self);
        return NULL;
}

static void machine__delete_dead_threads(struct machine *machine)
{
        struct thread *n, *t;

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

static void perf_session__delete_dead_threads(struct perf_session *session)
{
        machine__delete_dead_threads(&session->host_machine);
}

static void machine__delete_threads(struct machine *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);
        }
}

static void perf_session__delete_threads(struct perf_session *session)
{
        machine__delete_threads(&session->host_machine);
}

void perf_session__delete(struct perf_session *self)
{
        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 machine__remove_thread(struct machine *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;
}

static const u8 cpumodes[] = {
        PERF_RECORD_MISC_USER,
        PERF_RECORD_MISC_KERNEL,
        PERF_RECORD_MISC_GUEST_USER,
        PERF_RECORD_MISC_GUEST_KERNEL
};
#define NCPUMODES (sizeof(cpumodes)/sizeof(u8))

static void ip__resolve_ams(struct machine *self, struct thread *thread,
                            struct addr_map_symbol *ams,
                            u64 ip)
{
        struct addr_location al;
        size_t i;
        u8 m;

        memset(&al, 0, sizeof(al));

        for (i = 0; i < NCPUMODES; i++) {
                m = cpumodes[i];
                /*
                 * We cannot use the header.misc hint to determine whether a
                 * branch stack address is user, kernel, guest, hypervisor.
                 * Branches may straddle the kernel/user/hypervisor boundaries.
                 * Thus, we have to try consecutively until we find a match
                 * or else, the symbol is unknown
                 */
                thread__find_addr_location(thread, self, m, MAP__FUNCTION,
                                ip, &al, NULL);
                if (al.sym)
                        goto found;
        }
found:
        ams->addr = ip;
        ams->al_addr = al.addr;
        ams->sym = al.sym;
        ams->map = al.map;
}

struct branch_info *machine__resolve_bstack(struct machine *self,
                                            struct thread *thr,
                                            struct branch_stack *bs)
{
        struct branch_info *bi;
        unsigned int i;

        bi = calloc(bs->nr, sizeof(struct branch_info));
        if (!bi)
                return NULL;

        for (i = 0; i < bs->nr; i++) {
                ip__resolve_ams(self, thr, &bi[i].to, bs->entries[i].to);
                ip__resolve_ams(self, thr, &bi[i].from, bs->entries[i].from);
                bi[i].flags = bs->entries[i].flags;
        }
        return bi;
}

int machine__resolve_callchain(struct machine *self,
                               struct perf_evsel *evsel __used,
                               struct thread *thread,
                               struct ip_callchain *chain,
                               struct symbol **parent)
{
        u8 cpumode = PERF_RECORD_MISC_USER;
        unsigned int i;
        int err;

        callchain_cursor_reset(&callchain_cursor);

        if (chain->nr > PERF_MAX_STACK_DEPTH) {
                pr_warning("corrupted callchain. skipping...\n");
                return 0;
        }

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

                if (callchain_param.order == ORDER_CALLEE)
                        ip = chain->ips[i];
                else
                        ip = chain->ips[chain->nr - i - 1];

                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:
                                pr_debug("invalid callchain context: "
                                         "%"PRId64"\n", (s64) ip);
                                /*
                                 * It seems the callchain is corrupted.
                                 * Discard all.
                                 */
                                callchain_cursor_reset(&callchain_cursor);
                                return 0;
                        }
                        continue;
                }

                al.filtered = false;
                thread__find_addr_location(thread, self, cpumode,
                                           MAP__FUNCTION, 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;
                }

                err = callchain_cursor_append(&callchain_cursor,
                                              ip, al.map, al.sym);
                if (err)
                        return err;
        }

        return 0;
}

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

static int process_event_synth_attr_stub(union perf_event *event __used,
                                         struct perf_evlist **pevlist __used)
{
        dump_printf(": unhandled!\n");
        return 0;
}

static int process_event_sample_stub(struct perf_tool *tool __used,
                                     union perf_event *event __used,
                                     struct perf_sample *sample __used,
                                     struct perf_evsel *evsel __used,
                                     struct machine *machine __used)
{
        dump_printf(": unhandled!\n");
        return 0;
}

static int process_event_stub(struct perf_tool *tool __used,
                              union perf_event *event __used,
                              struct perf_sample *sample __used,
                              struct machine *machine __used)
{
        dump_printf(": unhandled!\n");
        return 0;
}

static int process_finished_round_stub(struct perf_tool *tool __used,
                                       union perf_event *event __used,
                                       struct perf_session *perf_session __used)
{
        dump_printf(": unhandled!\n");
        return 0;
}

static int process_event_type_stub(struct perf_tool *tool __used,
                                   union perf_event *event __used)
{
        dump_printf(": unhandled!\n");
        return 0;
}

static int process_finished_round(struct perf_tool *tool,
                                  union perf_event *event,
                                  struct perf_session *session);

static void perf_tool__fill_defaults(struct perf_tool *tool)
{
        if (tool->sample == NULL)
                tool->sample = process_event_sample_stub;
        if (tool->mmap == NULL)
                tool->mmap = process_event_stub;
        if (tool->comm == NULL)
                tool->comm = process_event_stub;
        if (tool->fork == NULL)
                tool->fork = process_event_stub;
        if (tool->exit == NULL)
                tool->exit = process_event_stub;
        if (tool->lost == NULL)
                tool->lost = perf_event__process_lost;
        if (tool->read == NULL)
                tool->read = process_event_sample_stub;
        if (tool->throttle == NULL)
                tool->throttle = process_event_stub;
        if (tool->unthrottle == NULL)
                tool->unthrottle = process_event_stub;
        if (tool->attr == NULL)
                tool->attr = process_event_synth_attr_stub;
        if (tool->event_type == NULL)
                tool->event_type = process_event_type_stub;
        if (tool->tracing_data == NULL)
                tool->tracing_data = process_event_synth_tracing_data_stub;
        if (tool->build_id == NULL)
                tool->build_id = process_finished_round_stub;
        if (tool->finished_round == NULL) {
                if (tool->ordered_samples)
                        tool->finished_round = process_finished_round;
                else
                        tool->finished_round = process_finished_round_stub;
        }
}
 
void mem_bswap_32(void *src, int byte_size)
{
        u32 *m = src;
        while (byte_size > 0) {
                *m = bswap_32(*m);
                byte_size -= sizeof(u32);
                ++m;
        }
}

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 swap_sample_id_all(union perf_event *event, void *data)
{
        void *end = (void *) event + event->header.size;
        int size = end - data;

        BUG_ON(size % sizeof(u64));
        mem_bswap_64(data, size);
}

static void perf_event__all64_swap(union perf_event *event,
                                   bool sample_id_all __used)
{
        struct perf_event_header *hdr = &event->header;
        mem_bswap_64(hdr + 1, event->header.size - sizeof(*hdr));
}

static void perf_event__comm_swap(union perf_event *event, bool sample_id_all)
{
        event->comm.pid = bswap_32(event->comm.pid);
        event->comm.tid = bswap_32(event->comm.tid);

        if (sample_id_all) {
                void *data = &event->comm.comm;

                data += ALIGN(strlen(data) + 1, sizeof(u64));
                swap_sample_id_all(event, data);
        }
}

static void perf_event__mmap_swap(union perf_event *event,
                                  bool sample_id_all)
{
        event->mmap.pid   = bswap_32(event->mmap.pid);
        event->mmap.tid   = bswap_32(event->mmap.tid);
        event->mmap.start = bswap_64(event->mmap.start);
        event->mmap.len   = bswap_64(event->mmap.len);
        event->mmap.pgoff = bswap_64(event->mmap.pgoff);

        if (sample_id_all) {
                void *data = &event->mmap.filename;

                data += ALIGN(strlen(data) + 1, sizeof(u64));
                swap_sample_id_all(event, data);
        }
}

static void perf_event__task_swap(union perf_event *event, bool sample_id_all)
{
        event->fork.pid  = bswap_32(event->fork.pid);
        event->fork.tid  = bswap_32(event->fork.tid);
        event->fork.ppid = bswap_32(event->fork.ppid);
        event->fork.ptid = bswap_32(event->fork.ptid);
        event->fork.time = bswap_64(event->fork.time);

        if (sample_id_all)
                swap_sample_id_all(event, &event->fork + 1);
}

static void perf_event__read_swap(union perf_event *event, bool sample_id_all)
{
        event->read.pid          = bswap_32(event->read.pid);
        event->read.tid          = bswap_32(event->read.tid);
        event->read.value        = bswap_64(event->read.value);
        event->read.time_enabled = bswap_64(event->read.time_enabled);
        event->read.time_running = bswap_64(event->read.time_running);
        event->read.id           = bswap_64(event->read.id);

        if (sample_id_all)
                swap_sample_id_all(event, &event->read + 1);
}

static u8 revbyte(u8 b)
{
        int rev = (b >> 4) | ((b & 0xf) << 4);
        rev = ((rev & 0xcc) >> 2) | ((rev & 0x33) << 2);
        rev = ((rev & 0xaa) >> 1) | ((rev & 0x55) << 1);
        return (u8) rev;
}

/*
 * XXX this is hack in attempt to carry flags bitfield
 * throught endian village. ABI says:
 *
 * Bit-fields are allocated from right to left (least to most significant)
 * on little-endian implementations and from left to right (most to least
 * significant) on big-endian implementations.
 *
 * The above seems to be byte specific, so we need to reverse each
 * byte of the bitfield. 'Internet' also says this might be implementation
 * specific and we probably need proper fix and carry perf_event_attr
 * bitfield flags in separate data file FEAT_ section. Thought this seems
 * to work for now.
 */
static void swap_bitfield(u8 *p, unsigned len)
{
        unsigned i;

        for (i = 0; i < len; i++) {
                *p = revbyte(*p);
                p++;
        }
}

/* exported for swapping attributes in file header */
void perf_event__attr_swap(struct perf_event_attr *attr)
{
        attr->type              = bswap_32(attr->type);
        attr->size              = bswap_32(attr->size);
        attr->config            = bswap_64(attr->config);
        attr->sample_period     = bswap_64(attr->sample_period);
        attr->sample_type       = bswap_64(attr->sample_type);
        attr->read_format       = bswap_64(attr->read_format);
        attr->wakeup_events     = bswap_32(attr->wakeup_events);
        attr->bp_type           = bswap_32(attr->bp_type);
        attr->bp_addr           = bswap_64(attr->bp_addr);
        attr->bp_len            = bswap_64(attr->bp_len);

        swap_bitfield((u8 *) (&attr->read_format + 1), sizeof(u64));
}

static void perf_event__hdr_attr_swap(union perf_event *event,
                                      bool sample_id_all __used)
{
        size_t size;

        perf_event__attr_swap(&event->attr.attr);

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

static void perf_event__event_type_swap(union perf_event *event,
                                        bool sample_id_all __used)
{
        event->event_type.event_type.event_id =
                bswap_64(event->event_type.event_type.event_id);
}

static void perf_event__tracing_data_swap(union perf_event *event,
                                          bool sample_id_all __used)
{
        event->tracing_data.size = bswap_32(event->tracing_data.size);
}

typedef void (*perf_event__swap_op)(union perf_event *event,
                                    bool sample_id_all);

static perf_event__swap_op perf_event__swap_ops[] = {
        [PERF_RECORD_MMAP]                = perf_event__mmap_swap,
        [PERF_RECORD_COMM]                = perf_event__comm_swap,
        [PERF_RECORD_FORK]                = perf_event__task_swap,
        [PERF_RECORD_EXIT]                = perf_event__task_swap,
        [PERF_RECORD_LOST]                = perf_event__all64_swap,
        [PERF_RECORD_READ]                = perf_event__read_swap,
        [PERF_RECORD_SAMPLE]              = perf_event__all64_swap,
        [PERF_RECORD_HEADER_ATTR]         = perf_event__hdr_attr_swap,
        [PERF_RECORD_HEADER_EVENT_TYPE]   = perf_event__event_type_swap,
        [PERF_RECORD_HEADER_TRACING_DATA] = perf_event__tracing_data_swap,
        [PERF_RECORD_HEADER_BUILD_ID]     = NULL,
        [PERF_RECORD_HEADER_MAX]          = NULL,
};

struct sample_queue {
        u64                     timestamp;
        u64                     file_offset;
        union perf_event        *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,
                                      union perf_event *event,
                                      struct perf_sample *sample,
                                      struct perf_tool *tool,
                                      u64 file_offset);

static void flush_sample_queue(struct perf_session *s,
                               struct perf_tool *tool)
{
        struct ordered_samples *os = &s->ordered_samples;
        struct list_head *head = &os->samples;
        struct sample_queue *tmp, *iter;
        struct perf_sample sample;
        u64 limit = os->next_flush;
        u64 last_ts = os->last_sample ? os->last_sample->timestamp : 0ULL;
        unsigned idx = 0, progress_next = os->nr_samples / 16;
        int ret;

        if (!tool->ordered_samples || !limit)
                return;

        list_for_each_entry_safe(iter, tmp, head, list) {
                if (iter->timestamp > limit)
                        break;

                ret = perf_session__parse_sample(s, iter->event, &sample);
                if (ret)
                        pr_err("Can't parse sample, err = %d\n", ret);
                else
                        perf_session_deliver_event(s, iter->event, &sample, tool,
                                                   iter->file_offset);

                os->last_flush = iter->timestamp;
                list_del(&iter->list);
                list_add(&iter->list, &os->sample_cache);
                if (++idx >= progress_next) {
                        progress_next += os->nr_samples / 16;
                        ui_progress__update(idx, os->nr_samples,
                                            "Processing time ordered events...");
                }
        }

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

        os->nr_samples = 0;
}

/*
 * 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(struct perf_tool *tool,
                                  union perf_event *event __used,
                                  struct perf_session *session)
{
        flush_sample_queue(session, tool);
        session->ordered_samples.next_flush = session->ordered_samples.max_timestamp;

        return 0;
}

/* The queue is ordered by time */
static void __queue_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->nr_samples;
        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);
        }
}

#define MAX_SAMPLE_BUFFER       (64 * 1024 / sizeof(struct sample_queue))

static int perf_session_queue_event(struct perf_session *s, union perf_event *event,
                                    struct perf_sample *sample, u64 file_offset)
{
        struct ordered_samples *os = &s->ordered_samples;
        struct list_head *sc = &os->sample_cache;
        u64 timestamp = sample->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;
        }

        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;

        __queue_event(new, s);

        return 0;
}

static void callchain__printf(struct perf_sample *sample)
{
        unsigned int i;

        printf("... chain: nr:%" PRIu64 "\n", sample->callchain->nr);

        for (i = 0; i < sample->callchain->nr; i++)
                printf("..... %2d: %016" PRIx64 "\n",
                       i, sample->callchain->ips[i]);
}

static void branch_stack__printf(struct perf_sample *sample)
{
        uint64_t i;

        printf("... branch stack: nr:%" PRIu64 "\n", sample->branch_stack->nr);

        for (i = 0; i < sample->branch_stack->nr; i++)
                printf("..... %2"PRIu64": %016" PRIx64 " -> %016" PRIx64 "\n",
                        i, sample->branch_stack->entries[i].from,
                        sample->branch_stack->entries[i].to);
}

static void perf_session__print_tstamp(struct perf_session *session,
                                       union perf_event *event,
                                       struct perf_sample *sample)
{
        if (event->header.type != PERF_RECORD_SAMPLE &&
            !session->sample_id_all) {
                fputs("-1 -1 ", stdout);
                return;
        }

        if ((session->sample_type & PERF_SAMPLE_CPU))
                printf("%u ", sample->cpu);

        if (session->sample_type & PERF_SAMPLE_TIME)
                printf("%" PRIu64 " ", sample->time);
}

static void dump_event(struct perf_session *session, union perf_event *event,
                       u64 file_offset, struct perf_sample *sample)
{
        if (!dump_trace)
                return;

        printf("\n%#" PRIx64 " [%#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("%#" PRIx64 " [%#x]: PERF_RECORD_%s", file_offset,
               event->header.size, perf_event__name(event->header.type));
}

static void dump_sample(struct perf_session *session, union perf_event *event,
                        struct perf_sample *sample)
{
        if (!dump_trace)
                return;

        printf("(IP, %d): %d/%d: %#" PRIx64 " period: %" PRIu64 " addr: %#" PRIx64 "\n",
               event->header.misc, sample->pid, sample->tid, sample->ip,
               sample->period, sample->addr);

        if (session->sample_type & PERF_SAMPLE_CALLCHAIN)
                callchain__printf(sample);

        if (session->sample_type & PERF_SAMPLE_BRANCH_STACK)
                branch_stack__printf(sample);
}

static struct machine *
        perf_session__find_machine_for_cpumode(struct perf_session *session,
                                               union perf_event *event)
{
        const u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;

        if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL && perf_guest) {
                u32 pid;

                if (event->header.type == PERF_RECORD_MMAP)
                        pid = event->mmap.pid;
                else
                        pid = event->ip.pid;

                return perf_session__findnew_machine(session, pid);
        }

        return perf_session__find_host_machine(session);
}

static int perf_session_deliver_event(struct perf_session *session,
                                      union perf_event *event,
                                      struct perf_sample *sample,
                                      struct perf_tool *tool,
                                      u64 file_offset)
{
        struct perf_evsel *evsel;
        struct machine *machine;

        dump_event(session, event, file_offset, sample);

        evsel = perf_evlist__id2evsel(session->evlist, sample->id);
        if (evsel != NULL && event->header.type != PERF_RECORD_SAMPLE) {
                /*
                 * XXX We're leaving PERF_RECORD_SAMPLE unnacounted here
                 * because the tools right now may apply filters, discarding
                 * some of the samples. For consistency, in the future we
                 * should have something like nr_filtered_samples and remove
                 * the sample->period from total_sample_period, etc, KISS for
                 * now tho.
                 *
                 * Also testing against NULL allows us to handle files without
                 * attr.sample_id_all and/or without PERF_SAMPLE_ID. In the
                 * future probably it'll be a good idea to restrict event
                 * processing via perf_session to files with both set.
                 */
                hists__inc_nr_events(&evsel->hists, event->header.type);
        }

        machine = perf_session__find_machine_for_cpumode(session, event);

        switch (event->header.type) {
        case PERF_RECORD_SAMPLE:
                dump_sample(session, event, sample);
                if (evsel == NULL) {
                        ++session->hists.stats.nr_unknown_id;
                        return 0;
                }
                if (machine == NULL) {
                        ++session->hists.stats.nr_unprocessable_samples;
                        return 0;
                }
                return tool->sample(tool, event, sample, evsel, machine);
        case PERF_RECORD_MMAP:
                return tool->mmap(tool, event, sample, machine);
        case PERF_RECORD_COMM:
                return tool->comm(tool, event, sample, machine);
        case PERF_RECORD_FORK:
                return tool->fork(tool, event, sample, machine);
        case PERF_RECORD_EXIT:
                return tool->exit(tool, event, sample, machine);
        case PERF_RECORD_LOST:
                if (tool->lost == perf_event__process_lost)
                        session->hists.stats.total_lost += event->lost.lost;
                return tool->lost(tool, event, sample, machine);
        case PERF_RECORD_READ:
                return tool->read(tool, event, sample, evsel, machine);
        case PERF_RECORD_THROTTLE:
                return tool->throttle(tool, event, sample, machine);
        case PERF_RECORD_UNTHROTTLE:
                return tool->unthrottle(tool, event, sample, machine);
        default:
                ++session->hists.stats.nr_unknown_events;
                return -1;
        }
}

static int perf_session__preprocess_sample(struct perf_session *session,
                                           union perf_event *event, struct perf_sample *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, union perf_event *event,
                                            struct perf_tool *tool, u64 file_offset)
{
        int err;

        dump_event(session, event, file_offset, NULL);

        /* These events are processed right away */
        switch (event->header.type) {
        case PERF_RECORD_HEADER_ATTR:
                err = tool->attr(event, &session->evlist);
                if (err == 0)
                        perf_session__update_sample_type(session);
                return err;
        case PERF_RECORD_HEADER_EVENT_TYPE:
                return tool->event_type(tool, event);
        case PERF_RECORD_HEADER_TRACING_DATA:
                /* setup for reading amidst mmap */
                lseek(session->fd, file_offset, SEEK_SET);
                return tool->tracing_data(event, session);
        case PERF_RECORD_HEADER_BUILD_ID:
                return tool->build_id(tool, event, session);
        case PERF_RECORD_FINISHED_ROUND:
                return tool->finished_round(tool, event, session);
        default:
                return -EINVAL;
        }
}

static void event_swap(union perf_event *event, bool sample_id_all)
{
        perf_event__swap_op swap;

        swap = perf_event__swap_ops[event->header.type];
        if (swap)
                swap(event, sample_id_all);
}

static int perf_session__process_event(struct perf_session *session,
                                       union perf_event *event,
                                       struct perf_tool *tool,
                                       u64 file_offset)
{
        struct perf_sample sample;
        int ret;

        if (session->header.needs_swap)
                event_swap(event, session->sample_id_all);

        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, tool, file_offset);

        /*
         * For all kernel events we get the sample data
         */
        ret = perf_session__parse_sample(session, event, &sample);
        if (ret)
                return ret;

        /* Preprocess sample records - precheck callchains */
        if (perf_session__preprocess_sample(session, event, &sample))
                return 0;

        if (tool->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, tool,
                                          file_offset);
}

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);
}

struct thread *perf_session__findnew(struct perf_session *session, pid_t pid)
{
        return machine__findnew_thread(&session->host_machine, pid);
}

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;
}

static void perf_session__warn_about_errors(const struct perf_session *session,
                                            const struct perf_tool *tool)
{
        if (tool->lost == perf_event__process_lost &&
            session->hists.stats.nr_events[PERF_RECORD_LOST] != 0) {
                ui__warning("Processed %d events and lost %d chunks!\n\n"
                            "Check IO/CPU overload!\n\n",
                            session->hists.stats.nr_events[0],
                            session->hists.stats.nr_events[PERF_RECORD_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);
        }

        if (session->hists.stats.nr_unknown_id != 0) {
                ui__warning("%u samples with id not present in the header\n",
                            session->hists.stats.nr_unknown_id);
        }

        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]);
        }

        if (session->hists.stats.nr_unprocessable_samples != 0) {
                ui__warning("%u unprocessable samples recorded.\n"
                            "Do you have a KVM guest running and not using 'perf kvm'?\n",
                            session->hists.stats.nr_unprocessable_samples);
        }
}

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

static int __perf_session__process_pipe_events(struct perf_session *self,
                                               struct perf_tool *tool)
{
        union perf_event *event;
        uint32_t size, cur_size = 0;
        void *buf = NULL;
        int skip = 0;
        u64 head;
        int err;
        void *p;

        perf_tool__fill_defaults(tool);

        head = 0;
        cur_size = sizeof(union perf_event);

        buf = malloc(cur_size);
        if (!buf)
                return -errno;
more:
        event = buf;
        err = readn(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;

        if (size > cur_size) {
                void *new = realloc(buf, size);
                if (!new) {
                        pr_err("failed to allocate memory to read event\n");
                        goto out_err;
                }
                buf = new;
                cur_size = size;
                event = buf;
        }
        p = event;
        p += sizeof(struct perf_event_header);

        if (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");
                                goto done;
                        }

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

        if ((skip = perf_session__process_event(self, event, tool, head)) < 0) {
                pr_err("%#" PRIx64 " [%#x]: failed to process type: %d\n",
                       head, event->header.size, event->header.type);
                err = -EINVAL;
                goto out_err;
        }

        head += size;

        if (skip > 0)
                head += skip;

        if (!session_done())
                goto more;
done:
        err = 0;
out_err:
        free(buf);
        perf_session__warn_about_errors(self, tool);
        perf_session_free_sample_buffers(self);
        return err;
}

static union perf_event *
fetch_mmaped_event(struct perf_session *session,
                   u64 head, size_t mmap_size, char *buf)
{
        union perf_event *event;

        /*
         * Ensure we have enough space remaining to read
         * the size of the event in the headers.
         */
        if (head + sizeof(event->header) > mmap_size)
                return NULL;

        event = (union perf_event *)(buf + head);

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

        if (head + event->header.size > mmap_size)
                return NULL;

        return event;
}

int __perf_session__process_events(struct perf_session *session,
                                   u64 data_offset, u64 data_size,
                                   u64 file_size, struct perf_tool *tool)
{
        u64 head, page_offset, file_offset, file_pos, progress_next;
        int err, mmap_prot, mmap_flags, map_idx = 0;
        size_t  page_size, mmap_size;
        char *buf, *mmaps[8];
        union perf_event *event;
        uint32_t size;

        perf_tool__fill_defaults(tool);

        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;

        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 (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;
        }
        mmaps[map_idx] = buf;
        map_idx = (map_idx + 1) & (ARRAY_SIZE(mmaps) - 1);
        file_pos = file_offset + head;

more:
        event = fetch_mmaped_event(session, head, mmap_size, buf);
        if (!event) {
                if (mmaps[map_idx]) {
                        munmap(mmaps[map_idx], mmap_size);
                        mmaps[map_idx] = NULL;
                }

                page_offset = page_size * (head / page_size);
                file_offset += page_offset;
                head -= page_offset;
                goto remap;
        }

        size = event->header.size;

        if (size == 0 ||
            perf_session__process_event(session, event, tool, file_pos) < 0) {
                pr_err("%#" PRIx64 " [%#x]: failed to process type: %d\n",
                       file_offset + head, event->header.size,
                       event->header.type);
                err = -EINVAL;
                goto out_err;
        }

        head += size;
        file_pos += size;

        if (file_pos >= progress_next) {
                progress_next += file_size / 16;
                ui_progress__update(file_pos, file_size,
                                    "Processing events...");
        }

        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, tool);
out_err:
        perf_session__warn_about_errors(session, tool);
        perf_session_free_sample_buffers(session);
        return err;
}

int perf_session__process_events(struct perf_session *self,
                                 struct perf_tool *tool)
{
        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, tool);
        else
                err = __perf_session__process_pipe_events(self, tool);

        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 maps__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);
}

size_t perf_session__fprintf_nr_events(struct perf_session *session, FILE *fp)
{
        struct perf_evsel *pos;
        size_t ret = fprintf(fp, "Aggregated stats:\n");

        ret += hists__fprintf_nr_events(&session->hists, fp);

        list_for_each_entry(pos, &session->evlist->entries, node) {
                ret += fprintf(fp, "%s stats:\n", event_name(pos));
                ret += hists__fprintf_nr_events(&pos->hists, fp);
        }

        return ret;
}

size_t perf_session__fprintf(struct perf_session *session, FILE *fp)
{
        /*
         * FIXME: Here we have to actually print all the machines in this
         * session, not just the host...
         */
        return machine__fprintf(&session->host_machine, fp);
}

void perf_session__remove_thread(struct perf_session *session,
                                 struct thread *th)
{
        /*
         * FIXME: This one makes no sense, we need to remove the thread from
         * the machine it belongs to, perf_session can have many machines, so
         * doing it always on ->host_machine is wrong.  Fix when auditing all
         * the 'perf kvm' code.
         */
        machine__remove_thread(&session->host_machine, th);
}

struct perf_evsel *perf_session__find_first_evtype(struct perf_session *session,
                                              unsigned int type)
{
        struct perf_evsel *pos;

        list_for_each_entry(pos, &session->evlist->entries, node) {
                if (pos->attr.type == type)
                        return pos;
        }
        return NULL;
}

void perf_event__print_ip(union perf_event *event, struct perf_sample *sample,
                          struct machine *machine, struct perf_evsel *evsel,
                          int print_sym, int print_dso, int print_symoffset)
{
        struct addr_location al;
        struct callchain_cursor_node *node;

        if (perf_event__preprocess_sample(event, machine, &al, sample,
                                          NULL) < 0) {
                error("problem processing %d event, skipping it.\n",
                        event->header.type);
                return;
        }

        if (symbol_conf.use_callchain && sample->callchain) {

                if (machine__resolve_callchain(machine, evsel, al.thread,
                                                sample->callchain, NULL) != 0) {
                        if (verbose)
                                error("Failed to resolve callchain. Skipping\n");
                        return;
                }
                callchain_cursor_commit(&callchain_cursor);

                while (1) {
                        node = callchain_cursor_current(&callchain_cursor);
                        if (!node)
                                break;

                        printf("\t%16" PRIx64, node->ip);
                        if (print_sym) {
                                printf(" ");
                                symbol__fprintf_symname(node->sym, stdout);
                        }
                        if (print_dso) {
                                printf(" (");
                                map__fprintf_dsoname(node->map, stdout);
                                printf(")");
                        }
                        printf("\n");

                        callchain_cursor_advance(&callchain_cursor);
                }

        } else {
                printf("%16" PRIx64, sample->ip);
                if (print_sym) {
                        printf(" ");
                        if (print_symoffset)
                                symbol__fprintf_symname_offs(al.sym, &al,
                                                             stdout);
                        else
                                symbol__fprintf_symname(al.sym, stdout);
                }

                if (print_dso) {
                        printf(" (");
                        map__fprintf_dsoname(al.map, stdout);
                        printf(")");
                }
        }
}

int perf_session__cpu_bitmap(struct perf_session *session,
                             const char *cpu_list, unsigned long *cpu_bitmap)
{
        int i;
        struct cpu_map *map;

        for (i = 0; i < PERF_TYPE_MAX; ++i) {
                struct perf_evsel *evsel;

                evsel = perf_session__find_first_evtype(session, i);
                if (!evsel)
                        continue;

                if (!(evsel->attr.sample_type & PERF_SAMPLE_CPU)) {
                        pr_err("File does not contain CPU events. "
                               "Remove -c option to proceed.\n");
                        return -1;
                }
        }

        map = cpu_map__new(cpu_list);
        if (map == NULL) {
                pr_err("Invalid cpu_list\n");
                return -1;
        }

        for (i = 0; i < map->nr; i++) {
                int cpu = map->map[i];

                if (cpu >= MAX_NR_CPUS) {
                        pr_err("Requested CPU %d too large. "
                               "Consider raising MAX_NR_CPUS\n", cpu);
                        return -1;
                }

                set_bit(cpu, cpu_bitmap);
        }

        return 0;
}

void perf_session__fprintf_info(struct perf_session *session, FILE *fp,
                                bool full)
{
        struct stat st;
        int ret;

        if (session == NULL || fp == NULL)
                return;

        ret = fstat(session->fd, &st);
        if (ret == -1)
                return;

        fprintf(fp, "# ========\n");
        fprintf(fp, "# captured on: %s", ctime(&st.st_ctime));
        perf_header__fprintf_info(session, fp, full);
        fprintf(fp, "# ========\n#\n");
}