evlist.c

Go to the documentation of this file.

/*
 * Copyright (C) 2011, Red Hat Inc, Arnaldo Carvalho de Melo <[email protected]>
 *
 * Parts came from builtin-{top,stat,record}.c, see those files for further
 * copyright notes.
 *
 * Released under the GPL v2. (and only v2, not any later version)
 */
#include "util.h"
#include "debugfs.h"
#include <poll.h>
#include "cpumap.h"
#include "thread_map.h"
#include "target.h"
#include "evlist.h"
#include "evsel.h"
#include <unistd.h>

#include "parse-events.h"

#include <sys/mman.h>

#include <linux/bitops.h>
#include <linux/hash.h>

#define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
#define SID(e, x, y) xyarray__entry(e->sample_id, x, y)

void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus,
               struct thread_map *threads)
{
    int i;

    for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
        INIT_HLIST_HEAD(&evlist->heads[i]);
    INIT_LIST_HEAD(&evlist->entries);
    perf_evlist__set_maps(evlist, cpus, threads);
    evlist->workload.pid = -1;
}

struct perf_evlist *perf_evlist__new(struct cpu_map *cpus,
                     struct thread_map *threads)
{
    struct perf_evlist *evlist = zalloc(sizeof(*evlist));

    if (evlist != NULL)
        perf_evlist__init(evlist, cpus, threads);

    return evlist;
}

void perf_evlist__config_attrs(struct perf_evlist *evlist,
                   struct perf_record_opts *opts)
{
    struct perf_evsel *evsel, *first;

    if (evlist->cpus->map[0] < 0)
        opts->no_inherit = true;

    first = perf_evlist__first(evlist);

    list_for_each_entry(evsel, &evlist->entries, node) {
        perf_evsel__config(evsel, opts, first);

        if (evlist->nr_entries > 1)
            evsel->attr.sample_type |= PERF_SAMPLE_ID;
    }
}

static void perf_evlist__purge(struct perf_evlist *evlist)
{
    struct perf_evsel *pos, *n;

    list_for_each_entry_safe(pos, n, &evlist->entries, node) {
        list_del_init(&pos->node);
        perf_evsel__delete(pos);
    }

    evlist->nr_entries = 0;
}

void perf_evlist__exit(struct perf_evlist *evlist)
{
    free(evlist->mmap);
    free(evlist->pollfd);
    evlist->mmap = NULL;
    evlist->pollfd = NULL;
}

void perf_evlist__delete(struct perf_evlist *evlist)
{
    perf_evlist__purge(evlist);
    perf_evlist__exit(evlist);
    free(evlist);
}

void perf_evlist__add(struct perf_evlist *evlist, struct perf_evsel *entry)
{
    list_add_tail(&entry->node, &evlist->entries);
    ++evlist->nr_entries;
}

void perf_evlist__splice_list_tail(struct perf_evlist *evlist,
                   struct list_head *list,
                   int nr_entries)
{
    list_splice_tail(list, &evlist->entries);
    evlist->nr_entries += nr_entries;
}

void __perf_evlist__set_leader(struct list_head *list)
{
    struct perf_evsel *evsel, *leader;

    leader = list_entry(list->next, struct perf_evsel, node);
    leader->leader = NULL;

    list_for_each_entry(evsel, list, node) {
        if (evsel != leader)
            evsel->leader = leader;
    }
}

void perf_evlist__set_leader(struct perf_evlist *evlist)
{
    if (evlist->nr_entries)
        __perf_evlist__set_leader(&evlist->entries);
}

int perf_evlist__add_default(struct perf_evlist *evlist)
{
    struct perf_event_attr attr = {
        .type = PERF_TYPE_HARDWARE,
        .config = PERF_COUNT_HW_CPU_CYCLES,
    };
    struct perf_evsel *evsel;

    event_attr_init(&attr);

    evsel = perf_evsel__new(&attr, 0);
    if (evsel == NULL)
        goto error;

    /* use strdup() because free(evsel) assumes name is allocated */
    evsel->name = strdup("cycles");
    if (!evsel->name)
        goto error_free;

    perf_evlist__add(evlist, evsel);
    return 0;
error_free:
    perf_evsel__delete(evsel);
error:
    return -ENOMEM;
}

static int perf_evlist__add_attrs(struct perf_evlist *evlist,
                  struct perf_event_attr *attrs, size_t nr_attrs)
{
    struct perf_evsel *evsel, *n;
    LIST_HEAD(head);
    size_t i;

    for (i = 0; i < nr_attrs; i++) {
        evsel = perf_evsel__new(attrs + i, evlist->nr_entries + i);
        if (evsel == NULL)
            goto out_delete_partial_list;
        list_add_tail(&evsel->node, &head);
    }

    perf_evlist__splice_list_tail(evlist, &head, nr_attrs);

    return 0;

out_delete_partial_list:
    list_for_each_entry_safe(evsel, n, &head, node)
        perf_evsel__delete(evsel);
    return -1;
}

int __perf_evlist__add_default_attrs(struct perf_evlist *evlist,
                     struct perf_event_attr *attrs, size_t nr_attrs)
{
    size_t i;

    for (i = 0; i < nr_attrs; i++)
        event_attr_init(attrs + i);

    return perf_evlist__add_attrs(evlist, attrs, nr_attrs);
}

struct perf_evsel *
perf_evlist__find_tracepoint_by_id(struct perf_evlist *evlist, int id)
{
    struct perf_evsel *evsel;

    list_for_each_entry(evsel, &evlist->entries, node) {
        if (evsel->attr.type   == PERF_TYPE_TRACEPOINT &&
            (int)evsel->attr.config == id)
            return evsel;
    }

    return NULL;
}

int perf_evlist__add_newtp(struct perf_evlist *evlist,
               const char *sys, const char *name, void *handler)
{
    struct perf_evsel *evsel;

    evsel = perf_evsel__newtp(sys, name, evlist->nr_entries);
    if (evsel == NULL)
        return -1;

    evsel->handler.func = handler;
    perf_evlist__add(evlist, evsel);
    return 0;
}

void perf_evlist__disable(struct perf_evlist *evlist)
{
    int cpu, thread;
    struct perf_evsel *pos;

    for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
        list_for_each_entry(pos, &evlist->entries, node) {
            for (thread = 0; thread < evlist->threads->nr; thread++)
                ioctl(FD(pos, cpu, thread),
                      PERF_EVENT_IOC_DISABLE, 0);
        }
    }
}

void perf_evlist__enable(struct perf_evlist *evlist)
{
    int cpu, thread;
    struct perf_evsel *pos;

    for (cpu = 0; cpu < cpu_map__nr(evlist->cpus); cpu++) {
        list_for_each_entry(pos, &evlist->entries, node) {
            for (thread = 0; thread < evlist->threads->nr; thread++)
                ioctl(FD(pos, cpu, thread),
                      PERF_EVENT_IOC_ENABLE, 0);
        }
    }
}

static int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
{
    int nfds = cpu_map__nr(evlist->cpus) * evlist->threads->nr * evlist->nr_entries;
    evlist->pollfd = malloc(sizeof(struct pollfd) * nfds);
    return evlist->pollfd != NULL ? 0 : -ENOMEM;
}

void perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd)
{
    fcntl(fd, F_SETFL, O_NONBLOCK);
    evlist->pollfd[evlist->nr_fds].fd = fd;
    evlist->pollfd[evlist->nr_fds].events = POLLIN;
    evlist->nr_fds++;
}

static void perf_evlist__id_hash(struct perf_evlist *evlist,
                 struct perf_evsel *evsel,
                 int cpu, int thread, u64 id)
{
    int hash;
    struct perf_sample_id *sid = SID(evsel, cpu, thread);

    sid->id = id;
    sid->evsel = evsel;
    hash = hash_64(sid->id, PERF_EVLIST__HLIST_BITS);
    hlist_add_head(&sid->node, &evlist->heads[hash]);
}

void perf_evlist__id_add(struct perf_evlist *evlist, struct perf_evsel *evsel,
             int cpu, int thread, u64 id)
{
    perf_evlist__id_hash(evlist, evsel, cpu, thread, id);
    evsel->id[evsel->ids++] = id;
}

static int perf_evlist__id_add_fd(struct perf_evlist *evlist,
                  struct perf_evsel *evsel,
                  int cpu, int thread, int fd)
{
    u64 read_data[4] = { 0, };
    int id_idx = 1; /* The first entry is the counter value */

    if (!(evsel->attr.read_format & PERF_FORMAT_ID) ||
        read(fd, &read_data, sizeof(read_data)) == -1)
        return -1;

    if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
        ++id_idx;
    if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
        ++id_idx;

    perf_evlist__id_add(evlist, evsel, cpu, thread, read_data[id_idx]);
    return 0;
}

struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id)
{
    struct hlist_head *head;
    struct hlist_node *pos;
    struct perf_sample_id *sid;
    int hash;

    if (evlist->nr_entries == 1)
        return perf_evlist__first(evlist);

    hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
    head = &evlist->heads[hash];

    hlist_for_each_entry(sid, pos, head, node)
        if (sid->id == id)
            return sid->evsel;

    if (!perf_evlist__sample_id_all(evlist))
        return perf_evlist__first(evlist);

    return NULL;
}

union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx)
{
    /* XXX Move this to perf.c, making it generally available */
    unsigned int page_size = sysconf(_SC_PAGE_SIZE);
    struct perf_mmap *md = &evlist->mmap[idx];
    unsigned int head = perf_mmap__read_head(md);
    unsigned int old = md->prev;
    unsigned char *data = md->base + page_size;
    union perf_event *event = NULL;

    if (evlist->overwrite) {
        /*
         * If we're further behind than half the buffer, there's a chance
         * the writer will bite our tail and mess up the samples under us.
         *
         * If we somehow ended up ahead of the head, we got messed up.
         *
         * In either case, truncate and restart at head.
         */
        int diff = head - old;
        if (diff > md->mask / 2 || diff < 0) {
            fprintf(stderr, "WARNING: failed to keep up with mmap data.\n");

            /*
             * head points to a known good entry, start there.
             */
            old = head;
        }
    }

    if (old != head) {
        size_t size;

        event = (union perf_event *)&data[old & md->mask];
        size = event->header.size;

        /*
         * Event straddles the mmap boundary -- header should always
         * be inside due to u64 alignment of output.
         */
        if ((old & md->mask) + size != ((old + size) & md->mask)) {
            unsigned int offset = old;
            unsigned int len = min(sizeof(*event), size), cpy;
            void *dst = &evlist->event_copy;

            do {
                cpy = min(md->mask + 1 - (offset & md->mask), len);
                memcpy(dst, &data[offset & md->mask], cpy);
                offset += cpy;
                dst += cpy;
                len -= cpy;
            } while (len);

            event = &evlist->event_copy;
        }

        old += size;
    }

    md->prev = old;

    if (!evlist->overwrite)
        perf_mmap__write_tail(md, old);

    return event;
}

void perf_evlist__munmap(struct perf_evlist *evlist)
{
    int i;

    for (i = 0; i < evlist->nr_mmaps; i++) {
        if (evlist->mmap[i].base != NULL) {
            munmap(evlist->mmap[i].base, evlist->mmap_len);
            evlist->mmap[i].base = NULL;
        }
    }

    free(evlist->mmap);
    evlist->mmap = NULL;
}

static int perf_evlist__alloc_mmap(struct perf_evlist *evlist)
{
    evlist->nr_mmaps = cpu_map__nr(evlist->cpus);
    if (cpu_map__all(evlist->cpus))
        evlist->nr_mmaps = evlist->threads->nr;
    evlist->mmap = zalloc(evlist->nr_mmaps * sizeof(struct perf_mmap));
    return evlist->mmap != NULL ? 0 : -ENOMEM;
}

static int __perf_evlist__mmap(struct perf_evlist *evlist,
                   int idx, int prot, int mask, int fd)
{
    evlist->mmap[idx].prev = 0;
    evlist->mmap[idx].mask = mask;
    evlist->mmap[idx].base = mmap(NULL, evlist->mmap_len, prot,
                      MAP_SHARED, fd, 0);
    if (evlist->mmap[idx].base == MAP_FAILED) {
        evlist->mmap[idx].base = NULL;
        return -1;
    }

    perf_evlist__add_pollfd(evlist, fd);
    return 0;
}

static int perf_evlist__mmap_per_cpu(struct perf_evlist *evlist, int prot, int mask)
{
    struct perf_evsel *evsel;
    int cpu, thread;

    for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
        int output = -1;

        for (thread = 0; thread < evlist->threads->nr; thread++) {
            list_for_each_entry(evsel, &evlist->entries, node) {
                int fd = FD(evsel, cpu, thread);

                if (output == -1) {
                    output = fd;
                    if (__perf_evlist__mmap(evlist, cpu,
                                prot, mask, output) < 0)
                        goto out_unmap;
                } else {
                    if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, output) != 0)
                        goto out_unmap;
                }

                if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
                    perf_evlist__id_add_fd(evlist, evsel, cpu, thread, fd) < 0)
                    goto out_unmap;
            }
        }
    }

    return 0;

out_unmap:
    for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
        if (evlist->mmap[cpu].base != NULL) {
            munmap(evlist->mmap[cpu].base, evlist->mmap_len);
            evlist->mmap[cpu].base = NULL;
        }
    }
    return -1;
}

static int perf_evlist__mmap_per_thread(struct perf_evlist *evlist, int prot, int mask)
{
    struct perf_evsel *evsel;
    int thread;

    for (thread = 0; thread < evlist->threads->nr; thread++) {
        int output = -1;

        list_for_each_entry(evsel, &evlist->entries, node) {
            int fd = FD(evsel, 0, thread);

            if (output == -1) {
                output = fd;
                if (__perf_evlist__mmap(evlist, thread,
                            prot, mask, output) < 0)
                    goto out_unmap;
            } else {
                if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, output) != 0)
                    goto out_unmap;
            }

            if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
                perf_evlist__id_add_fd(evlist, evsel, 0, thread, fd) < 0)
                goto out_unmap;
        }
    }

    return 0;

out_unmap:
    for (thread = 0; thread < evlist->threads->nr; thread++) {
        if (evlist->mmap[thread].base != NULL) {
            munmap(evlist->mmap[thread].base, evlist->mmap_len);
            evlist->mmap[thread].base = NULL;
        }
    }
    return -1;
}

int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,
              bool overwrite)
{
    unsigned int page_size = sysconf(_SC_PAGE_SIZE);
    struct perf_evsel *evsel;
    const struct cpu_map *cpus = evlist->cpus;
    const struct thread_map *threads = evlist->threads;
    int prot = PROT_READ | (overwrite ? 0 : PROT_WRITE), mask;

        /* 512 kiB: default amount of unprivileged mlocked memory */
        if (pages == UINT_MAX)
                pages = (512 * 1024) / page_size;
    else if (!is_power_of_2(pages))
        return -EINVAL;

    mask = pages * page_size - 1;

    if (evlist->mmap == NULL && perf_evlist__alloc_mmap(evlist) < 0)
        return -ENOMEM;

    if (evlist->pollfd == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
        return -ENOMEM;

    evlist->overwrite = overwrite;
    evlist->mmap_len = (pages + 1) * page_size;

    list_for_each_entry(evsel, &evlist->entries, node) {
        if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
            evsel->sample_id == NULL &&
            perf_evsel__alloc_id(evsel, cpu_map__nr(cpus), threads->nr) < 0)
            return -ENOMEM;
    }

    if (cpu_map__all(cpus))
        return perf_evlist__mmap_per_thread(evlist, prot, mask);

    return perf_evlist__mmap_per_cpu(evlist, prot, mask);
}

int perf_evlist__create_maps(struct perf_evlist *evlist,
                 struct perf_target *target)
{
    evlist->threads = thread_map__new_str(target->pid, target->tid,
                          target->uid);

    if (evlist->threads == NULL)
        return -1;

    if (perf_target__has_task(target))
        evlist->cpus = cpu_map__dummy_new();
    else if (!perf_target__has_cpu(target) && !target->uses_mmap)
        evlist->cpus = cpu_map__dummy_new();
    else
        evlist->cpus = cpu_map__new(target->cpu_list);

    if (evlist->cpus == NULL)
        goto out_delete_threads;

    return 0;

out_delete_threads:
    thread_map__delete(evlist->threads);
    return -1;
}

void perf_evlist__delete_maps(struct perf_evlist *evlist)
{
    cpu_map__delete(evlist->cpus);
    thread_map__delete(evlist->threads);
    evlist->cpus    = NULL;
    evlist->threads = NULL;
}

int perf_evlist__apply_filters(struct perf_evlist *evlist)
{
    struct perf_evsel *evsel;
    int err = 0;
    const int ncpus = cpu_map__nr(evlist->cpus),
          nthreads = evlist->threads->nr;

    list_for_each_entry(evsel, &evlist->entries, node) {
        if (evsel->filter == NULL)
            continue;

        err = perf_evsel__set_filter(evsel, ncpus, nthreads, evsel->filter);
        if (err)
            break;
    }

    return err;
}

int perf_evlist__set_filter(struct perf_evlist *evlist, const char *filter)
{
    struct perf_evsel *evsel;
    int err = 0;
    const int ncpus = cpu_map__nr(evlist->cpus),
          nthreads = evlist->threads->nr;

    list_for_each_entry(evsel, &evlist->entries, node) {
        err = perf_evsel__set_filter(evsel, ncpus, nthreads, filter);
        if (err)
            break;
    }

    return err;
}

bool perf_evlist__valid_sample_type(struct perf_evlist *evlist)
{
    struct perf_evsel *first = perf_evlist__first(evlist), *pos = first;

    list_for_each_entry_continue(pos, &evlist->entries, node) {
        if (first->attr.sample_type != pos->attr.sample_type)
            return false;
    }

    return true;
}

u64 perf_evlist__sample_type(struct perf_evlist *evlist)
{
    struct perf_evsel *first = perf_evlist__first(evlist);
    return first->attr.sample_type;
}

u16 perf_evlist__id_hdr_size(struct perf_evlist *evlist)
{
    struct perf_evsel *first = perf_evlist__first(evlist);
    struct perf_sample *data;
    u64 sample_type;
    u16 size = 0;

    if (!first->attr.sample_id_all)
        goto out;

    sample_type = first->attr.sample_type;

    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:
    return size;
}

bool perf_evlist__valid_sample_id_all(struct perf_evlist *evlist)
{
    struct perf_evsel *first = perf_evlist__first(evlist), *pos = first;

    list_for_each_entry_continue(pos, &evlist->entries, node) {
        if (first->attr.sample_id_all != pos->attr.sample_id_all)
            return false;
    }

    return true;
}

bool perf_evlist__sample_id_all(struct perf_evlist *evlist)
{
    struct perf_evsel *first = perf_evlist__first(evlist);
    return first->attr.sample_id_all;
}

void perf_evlist__set_selected(struct perf_evlist *evlist,
                   struct perf_evsel *evsel)
{
    evlist->selected = evsel;
}

int perf_evlist__open(struct perf_evlist *evlist)
{
    struct perf_evsel *evsel;
    int err, ncpus, nthreads;

    list_for_each_entry(evsel, &evlist->entries, node) {
        err = perf_evsel__open(evsel, evlist->cpus, evlist->threads);
        if (err < 0)
            goto out_err;
    }

    return 0;
out_err:
    ncpus = evlist->cpus ? evlist->cpus->nr : 1;
    nthreads = evlist->threads ? evlist->threads->nr : 1;

    list_for_each_entry_reverse(evsel, &evlist->entries, node)
        perf_evsel__close(evsel, ncpus, nthreads);

    errno = -err;
    return err;
}

int perf_evlist__prepare_workload(struct perf_evlist *evlist,
                  struct perf_record_opts *opts,
                  const char *argv[])
{
    int child_ready_pipe[2], go_pipe[2];
    char bf;

    if (pipe(child_ready_pipe) < 0) {
        perror("failed to create 'ready' pipe");
        return -1;
    }

    if (pipe(go_pipe) < 0) {
        perror("failed to create 'go' pipe");
        goto out_close_ready_pipe;
    }

    evlist->workload.pid = fork();
    if (evlist->workload.pid < 0) {
        perror("failed to fork");
        goto out_close_pipes;
    }

    if (!evlist->workload.pid) {
        if (opts->pipe_output)
            dup2(2, 1);

        close(child_ready_pipe[0]);
        close(go_pipe[1]);
        fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);

        /*
         * Do a dummy execvp to get the PLT entry resolved,
         * so we avoid the resolver overhead on the real
         * execvp call.
         */
        execvp("", (char **)argv);

        /*
         * Tell the parent we're ready to go
         */
        close(child_ready_pipe[1]);

        /*
         * Wait until the parent tells us to go.
         */
        if (read(go_pipe[0], &bf, 1) == -1)
            perror("unable to read pipe");

        execvp(argv[0], (char **)argv);

        perror(argv[0]);
        kill(getppid(), SIGUSR1);
        exit(-1);
    }

    if (perf_target__none(&opts->target))
        evlist->threads->map[0] = evlist->workload.pid;

    close(child_ready_pipe[1]);
    close(go_pipe[0]);
    /*
     * wait for child to settle
     */
    if (read(child_ready_pipe[0], &bf, 1) == -1) {
        perror("unable to read pipe");
        goto out_close_pipes;
    }

    evlist->workload.cork_fd = go_pipe[1];
    close(child_ready_pipe[0]);
    return 0;

out_close_pipes:
    close(go_pipe[0]);
    close(go_pipe[1]);
out_close_ready_pipe:
    close(child_ready_pipe[0]);
    close(child_ready_pipe[1]);
    return -1;
}

int perf_evlist__start_workload(struct perf_evlist *evlist)
{
    if (evlist->workload.cork_fd > 0) {
        /*
         * Remove the cork, let it rip!
         */
        return close(evlist->workload.cork_fd);
    }

    return 0;
}

int perf_evlist__parse_sample(struct perf_evlist *evlist, union perf_event *event,
                  struct perf_sample *sample)
{
    struct perf_evsel *evsel = perf_evlist__first(evlist);
    return perf_evsel__parse_sample(evsel, event, sample);
}

size_t perf_evlist__fprintf(struct perf_evlist *evlist, FILE *fp)
{
    struct perf_evsel *evsel;
    size_t printed = 0;

    list_for_each_entry(evsel, &evlist->entries, node) {
        printed += fprintf(fp, "%s%s", evsel->idx ? ", " : "",
                   perf_evsel__name(evsel));
    }

    return printed + fprintf(fp, "\n");;
}