builtin-kmem.c

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#include "builtin.h"
#include "perf.h"

#include "util/evlist.h"
#include "util/evsel.h"
#include "util/util.h"
#include "util/cache.h"
#include "util/symbol.h"
#include "util/thread.h"
#include "util/header.h"
#include "util/session.h"
#include "util/tool.h"

#include "util/parse-options.h"
#include "util/trace-event.h"

#include "util/debug.h"

#include <linux/rbtree.h>

struct alloc_stat;
typedef int (*sort_fn_t)(struct alloc_stat *, struct alloc_stat *);

static int          alloc_flag;
static int          caller_flag;

static int          alloc_lines = -1;
static int          caller_lines = -1;

static bool         raw_ip;

static int          *cpunode_map;
static int          max_cpu_num;

struct alloc_stat {
    u64 call_site;
    u64 ptr;
    u64 bytes_req;
    u64 bytes_alloc;
    u32 hit;
    u32 pingpong;

    short   alloc_cpu;

    struct rb_node node;
};

static struct rb_root root_alloc_stat;
static struct rb_root root_alloc_sorted;
static struct rb_root root_caller_stat;
static struct rb_root root_caller_sorted;

static unsigned long total_requested, total_allocated;
static unsigned long nr_allocs, nr_cross_allocs;

#define PATH_SYS_NODE   "/sys/devices/system/node"

static int init_cpunode_map(void)
{
    FILE *fp;
    int i, err = -1;

    fp = fopen("/sys/devices/system/cpu/kernel_max", "r");
    if (!fp) {
        max_cpu_num = 4096;
        return 0;
    }

    if (fscanf(fp, "%d", &max_cpu_num) < 1) {
        pr_err("Failed to read 'kernel_max' from sysfs");
        goto out_close;
    }

    max_cpu_num++;

    cpunode_map = calloc(max_cpu_num, sizeof(int));
    if (!cpunode_map) {
        pr_err("%s: calloc failed\n", __func__);
        goto out_close;
    }

    for (i = 0; i < max_cpu_num; i++)
        cpunode_map[i] = -1;

    err = 0;
out_close:
    fclose(fp);
    return err;
}

static int setup_cpunode_map(void)
{
    struct dirent *dent1, *dent2;
    DIR *dir1, *dir2;
    unsigned int cpu, mem;
    char buf[PATH_MAX];

    if (init_cpunode_map())
        return -1;

    dir1 = opendir(PATH_SYS_NODE);
    if (!dir1)
        return -1;

    while ((dent1 = readdir(dir1)) != NULL) {
        if (dent1->d_type != DT_DIR ||
            sscanf(dent1->d_name, "node%u", &mem) < 1)
            continue;

        snprintf(buf, PATH_MAX, "%s/%s", PATH_SYS_NODE, dent1->d_name);
        dir2 = opendir(buf);
        if (!dir2)
            continue;
        while ((dent2 = readdir(dir2)) != NULL) {
            if (dent2->d_type != DT_LNK ||
                sscanf(dent2->d_name, "cpu%u", &cpu) < 1)
                continue;
            cpunode_map[cpu] = mem;
        }
        closedir(dir2);
    }
    closedir(dir1);
    return 0;
}

static int insert_alloc_stat(unsigned long call_site, unsigned long ptr,
                 int bytes_req, int bytes_alloc, int cpu)
{
    struct rb_node **node = &root_alloc_stat.rb_node;
    struct rb_node *parent = NULL;
    struct alloc_stat *data = NULL;

    while (*node) {
        parent = *node;
        data = rb_entry(*node, struct alloc_stat, node);

        if (ptr > data->ptr)
            node = &(*node)->rb_right;
        else if (ptr < data->ptr)
            node = &(*node)->rb_left;
        else
            break;
    }

    if (data && data->ptr == ptr) {
        data->hit++;
        data->bytes_req += bytes_req;
        data->bytes_alloc += bytes_alloc;
    } else {
        data = malloc(sizeof(*data));
        if (!data) {
            pr_err("%s: malloc failed\n", __func__);
            return -1;
        }
        data->ptr = ptr;
        data->pingpong = 0;
        data->hit = 1;
        data->bytes_req = bytes_req;
        data->bytes_alloc = bytes_alloc;

        rb_link_node(&data->node, parent, node);
        rb_insert_color(&data->node, &root_alloc_stat);
    }
    data->call_site = call_site;
    data->alloc_cpu = cpu;
    return 0;
}

static int insert_caller_stat(unsigned long call_site,
                  int bytes_req, int bytes_alloc)
{
    struct rb_node **node = &root_caller_stat.rb_node;
    struct rb_node *parent = NULL;
    struct alloc_stat *data = NULL;

    while (*node) {
        parent = *node;
        data = rb_entry(*node, struct alloc_stat, node);

        if (call_site > data->call_site)
            node = &(*node)->rb_right;
        else if (call_site < data->call_site)
            node = &(*node)->rb_left;
        else
            break;
    }

    if (data && data->call_site == call_site) {
        data->hit++;
        data->bytes_req += bytes_req;
        data->bytes_alloc += bytes_alloc;
    } else {
        data = malloc(sizeof(*data));
        if (!data) {
            pr_err("%s: malloc failed\n", __func__);
            return -1;
        }
        data->call_site = call_site;
        data->pingpong = 0;
        data->hit = 1;
        data->bytes_req = bytes_req;
        data->bytes_alloc = bytes_alloc;

        rb_link_node(&data->node, parent, node);
        rb_insert_color(&data->node, &root_caller_stat);
    }

    return 0;
}

static int perf_evsel__process_alloc_event(struct perf_evsel *evsel,
                       struct perf_sample *sample)
{
    unsigned long ptr = perf_evsel__intval(evsel, sample, "ptr"),
              call_site = perf_evsel__intval(evsel, sample, "call_site");
    int bytes_req = perf_evsel__intval(evsel, sample, "bytes_req"),
        bytes_alloc = perf_evsel__intval(evsel, sample, "bytes_alloc");

    if (insert_alloc_stat(call_site, ptr, bytes_req, bytes_alloc, sample->cpu) ||
        insert_caller_stat(call_site, bytes_req, bytes_alloc))
        return -1;

    total_requested += bytes_req;
    total_allocated += bytes_alloc;

    nr_allocs++;
    return 0;
}

static int perf_evsel__process_alloc_node_event(struct perf_evsel *evsel,
                        struct perf_sample *sample)
{
    int ret = perf_evsel__process_alloc_event(evsel, sample);

    if (!ret) {
        int node1 = cpunode_map[sample->cpu],
            node2 = perf_evsel__intval(evsel, sample, "node");

        if (node1 != node2)
            nr_cross_allocs++;
    }

    return ret;
}

static int ptr_cmp(struct alloc_stat *, struct alloc_stat *);
static int callsite_cmp(struct alloc_stat *, struct alloc_stat *);

static struct alloc_stat *search_alloc_stat(unsigned long ptr,
                        unsigned long call_site,
                        struct rb_root *root,
                        sort_fn_t sort_fn)
{
    struct rb_node *node = root->rb_node;
    struct alloc_stat key = { .ptr = ptr, .call_site = call_site };

    while (node) {
        struct alloc_stat *data;
        int cmp;

        data = rb_entry(node, struct alloc_stat, node);

        cmp = sort_fn(&key, data);
        if (cmp < 0)
            node = node->rb_left;
        else if (cmp > 0)
            node = node->rb_right;
        else
            return data;
    }
    return NULL;
}

static int perf_evsel__process_free_event(struct perf_evsel *evsel,
                      struct perf_sample *sample)
{
    unsigned long ptr = perf_evsel__intval(evsel, sample, "ptr");
    struct alloc_stat *s_alloc, *s_caller;

    s_alloc = search_alloc_stat(ptr, 0, &root_alloc_stat, ptr_cmp);
    if (!s_alloc)
        return 0;

    if ((short)sample->cpu != s_alloc->alloc_cpu) {
        s_alloc->pingpong++;

        s_caller = search_alloc_stat(0, s_alloc->call_site,
                         &root_caller_stat, callsite_cmp);
        if (!s_caller)
            return -1;
        s_caller->pingpong++;
    }
    s_alloc->alloc_cpu = -1;

    return 0;
}

typedef int (*tracepoint_handler)(struct perf_evsel *evsel,
                  struct perf_sample *sample);

static int process_sample_event(struct perf_tool *tool __maybe_unused,
                union perf_event *event,
                struct perf_sample *sample,
                struct perf_evsel *evsel,
                struct machine *machine)
{
    struct thread *thread = machine__findnew_thread(machine, event->ip.pid);

    if (thread == NULL) {
        pr_debug("problem processing %d event, skipping it.\n",
             event->header.type);
        return -1;
    }

    dump_printf(" ... thread: %s:%d\n", thread->comm, thread->pid);

    if (evsel->handler.func != NULL) {
        tracepoint_handler f = evsel->handler.func;
        return f(evsel, sample);
    }

    return 0;
}

static struct perf_tool perf_kmem = {
    .sample      = process_sample_event,
    .comm        = perf_event__process_comm,
    .ordered_samples = true,
};

static double fragmentation(unsigned long n_req, unsigned long n_alloc)
{
    if (n_alloc == 0)
        return 0.0;
    else
        return 100.0 - (100.0 * n_req / n_alloc);
}

static void __print_result(struct rb_root *root, struct perf_session *session,
               int n_lines, int is_caller)
{
    struct rb_node *next;
    struct machine *machine;

    printf("%.102s\n", graph_dotted_line);
    printf(" %-34s |",  is_caller ? "Callsite": "Alloc Ptr");
    printf(" Total_alloc/Per | Total_req/Per   | Hit      | Ping-pong | Frag\n");
    printf("%.102s\n", graph_dotted_line);

    next = rb_first(root);

    machine = perf_session__find_host_machine(session);
    if (!machine) {
        pr_err("__print_result: couldn't find kernel information\n");
        return;
    }
    while (next && n_lines--) {
        struct alloc_stat *data = rb_entry(next, struct alloc_stat,
                           node);
        struct symbol *sym = NULL;
        struct map *map;
        char buf[BUFSIZ];
        u64 addr;

        if (is_caller) {
            addr = data->call_site;
            if (!raw_ip)
                sym = machine__find_kernel_function(machine, addr, &map, NULL);
        } else
            addr = data->ptr;

        if (sym != NULL)
            snprintf(buf, sizeof(buf), "%s+%" PRIx64 "", sym->name,
                 addr - map->unmap_ip(map, sym->start));
        else
            snprintf(buf, sizeof(buf), "%#" PRIx64 "", addr);
        printf(" %-34s |", buf);

        printf(" %9llu/%-5lu | %9llu/%-5lu | %8lu | %8lu | %6.3f%%\n",
               (unsigned long long)data->bytes_alloc,
               (unsigned long)data->bytes_alloc / data->hit,
               (unsigned long long)data->bytes_req,
               (unsigned long)data->bytes_req / data->hit,
               (unsigned long)data->hit,
               (unsigned long)data->pingpong,
               fragmentation(data->bytes_req, data->bytes_alloc));

        next = rb_next(next);
    }

    if (n_lines == -1)
        printf(" ...                                | ...             | ...             | ...    | ...      | ...   \n");

    printf("%.102s\n", graph_dotted_line);
}

static void print_summary(void)
{
    printf("\nSUMMARY\n=======\n");
    printf("Total bytes requested: %lu\n", total_requested);
    printf("Total bytes allocated: %lu\n", total_allocated);
    printf("Total bytes wasted on internal fragmentation: %lu\n",
           total_allocated - total_requested);
    printf("Internal fragmentation: %f%%\n",
           fragmentation(total_requested, total_allocated));
    printf("Cross CPU allocations: %lu/%lu\n", nr_cross_allocs, nr_allocs);
}

static void print_result(struct perf_session *session)
{
    if (caller_flag)
        __print_result(&root_caller_sorted, session, caller_lines, 1);
    if (alloc_flag)
        __print_result(&root_alloc_sorted, session, alloc_lines, 0);
    print_summary();
}

struct sort_dimension {
    const char      name[20];
    sort_fn_t       cmp;
    struct list_head    list;
};

static LIST_HEAD(caller_sort);
static LIST_HEAD(alloc_sort);

static void sort_insert(struct rb_root *root, struct alloc_stat *data,
            struct list_head *sort_list)
{
    struct rb_node **new = &(root->rb_node);
    struct rb_node *parent = NULL;
    struct sort_dimension *sort;

    while (*new) {
        struct alloc_stat *this;
        int cmp = 0;

        this = rb_entry(*new, struct alloc_stat, node);
        parent = *new;

        list_for_each_entry(sort, sort_list, list) {
            cmp = sort->cmp(data, this);
            if (cmp)
                break;
        }

        if (cmp > 0)
            new = &((*new)->rb_left);
        else
            new = &((*new)->rb_right);
    }

    rb_link_node(&data->node, parent, new);
    rb_insert_color(&data->node, root);
}

static void __sort_result(struct rb_root *root, struct rb_root *root_sorted,
              struct list_head *sort_list)
{
    struct rb_node *node;
    struct alloc_stat *data;

    for (;;) {
        node = rb_first(root);
        if (!node)
            break;

        rb_erase(node, root);
        data = rb_entry(node, struct alloc_stat, node);
        sort_insert(root_sorted, data, sort_list);
    }
}

static void sort_result(void)
{
    __sort_result(&root_alloc_stat, &root_alloc_sorted, &alloc_sort);
    __sort_result(&root_caller_stat, &root_caller_sorted, &caller_sort);
}

static int __cmd_kmem(const char *input_name)
{
    int err = -EINVAL;
    struct perf_session *session;
    const struct perf_evsel_str_handler kmem_tracepoints[] = {
        { "kmem:kmalloc",       perf_evsel__process_alloc_event, },
            { "kmem:kmem_cache_alloc",  perf_evsel__process_alloc_event, },
        { "kmem:kmalloc_node",      perf_evsel__process_alloc_node_event, },
            { "kmem:kmem_cache_alloc_node", perf_evsel__process_alloc_node_event, },
        { "kmem:kfree",         perf_evsel__process_free_event, },
            { "kmem:kmem_cache_free",   perf_evsel__process_free_event, },
    };

    session = perf_session__new(input_name, O_RDONLY, 0, false, &perf_kmem);
    if (session == NULL)
        return -ENOMEM;

    if (perf_session__create_kernel_maps(session) < 0)
        goto out_delete;

    if (!perf_session__has_traces(session, "kmem record"))
        goto out_delete;

    if (perf_session__set_tracepoints_handlers(session, kmem_tracepoints)) {
        pr_err("Initializing perf session tracepoint handlers failed\n");
        return -1;
    }

    setup_pager();
    err = perf_session__process_events(session, &perf_kmem);
    if (err != 0)
        goto out_delete;
    sort_result();
    print_result(session);
out_delete:
    perf_session__delete(session);
    return err;
}

static int ptr_cmp(struct alloc_stat *l, struct alloc_stat *r)
{
    if (l->ptr < r->ptr)
        return -1;
    else if (l->ptr > r->ptr)
        return 1;
    return 0;
}

static struct sort_dimension ptr_sort_dimension = {
    .name   = "ptr",
    .cmp    = ptr_cmp,
};

static int callsite_cmp(struct alloc_stat *l, struct alloc_stat *r)
{
    if (l->call_site < r->call_site)
        return -1;
    else if (l->call_site > r->call_site)
        return 1;
    return 0;
}

static struct sort_dimension callsite_sort_dimension = {
    .name   = "callsite",
    .cmp    = callsite_cmp,
};

static int hit_cmp(struct alloc_stat *l, struct alloc_stat *r)
{
    if (l->hit < r->hit)
        return -1;
    else if (l->hit > r->hit)
        return 1;
    return 0;
}

static struct sort_dimension hit_sort_dimension = {
    .name   = "hit",
    .cmp    = hit_cmp,
};

static int bytes_cmp(struct alloc_stat *l, struct alloc_stat *r)
{
    if (l->bytes_alloc < r->bytes_alloc)
        return -1;
    else if (l->bytes_alloc > r->bytes_alloc)
        return 1;
    return 0;
}

static struct sort_dimension bytes_sort_dimension = {
    .name   = "bytes",
    .cmp    = bytes_cmp,
};

static int frag_cmp(struct alloc_stat *l, struct alloc_stat *r)
{
    double x, y;

    x = fragmentation(l->bytes_req, l->bytes_alloc);
    y = fragmentation(r->bytes_req, r->bytes_alloc);

    if (x < y)
        return -1;
    else if (x > y)
        return 1;
    return 0;
}

static struct sort_dimension frag_sort_dimension = {
    .name   = "frag",
    .cmp    = frag_cmp,
};

static int pingpong_cmp(struct alloc_stat *l, struct alloc_stat *r)
{
    if (l->pingpong < r->pingpong)
        return -1;
    else if (l->pingpong > r->pingpong)
        return 1;
    return 0;
}

static struct sort_dimension pingpong_sort_dimension = {
    .name   = "pingpong",
    .cmp    = pingpong_cmp,
};

static struct sort_dimension *avail_sorts[] = {
    &ptr_sort_dimension,
    &callsite_sort_dimension,
    &hit_sort_dimension,
    &bytes_sort_dimension,
    &frag_sort_dimension,
    &pingpong_sort_dimension,
};

#define NUM_AVAIL_SORTS \
    (int)(sizeof(avail_sorts) / sizeof(struct sort_dimension *))

static int sort_dimension__add(const char *tok, struct list_head *list)
{
    struct sort_dimension *sort;
    int i;

    for (i = 0; i < NUM_AVAIL_SORTS; i++) {
        if (!strcmp(avail_sorts[i]->name, tok)) {
            sort = malloc(sizeof(*sort));
            if (!sort) {
                pr_err("%s: malloc failed\n", __func__);
                return -1;
            }
            memcpy(sort, avail_sorts[i], sizeof(*sort));
            list_add_tail(&sort->list, list);
            return 0;
        }
    }

    return -1;
}

static int setup_sorting(struct list_head *sort_list, const char *arg)
{
    char *tok;
    char *str = strdup(arg);

    if (!str) {
        pr_err("%s: strdup failed\n", __func__);
        return -1;
    }

    while (true) {
        tok = strsep(&str, ",");
        if (!tok)
            break;
        if (sort_dimension__add(tok, sort_list) < 0) {
            error("Unknown --sort key: '%s'", tok);
            free(str);
            return -1;
        }
    }

    free(str);
    return 0;
}

static int parse_sort_opt(const struct option *opt __maybe_unused,
              const char *arg, int unset __maybe_unused)
{
    if (!arg)
        return -1;

    if (caller_flag > alloc_flag)
        return setup_sorting(&caller_sort, arg);
    else
        return setup_sorting(&alloc_sort, arg);

    return 0;
}

static int parse_caller_opt(const struct option *opt __maybe_unused,
                const char *arg __maybe_unused,
                int unset __maybe_unused)
{
    caller_flag = (alloc_flag + 1);
    return 0;
}

static int parse_alloc_opt(const struct option *opt __maybe_unused,
               const char *arg __maybe_unused,
               int unset __maybe_unused)
{
    alloc_flag = (caller_flag + 1);
    return 0;
}

static int parse_line_opt(const struct option *opt __maybe_unused,
              const char *arg, int unset __maybe_unused)
{
    int lines;

    if (!arg)
        return -1;

    lines = strtoul(arg, NULL, 10);

    if (caller_flag > alloc_flag)
        caller_lines = lines;
    else
        alloc_lines = lines;

    return 0;
}

static int __cmd_record(int argc, const char **argv)
{
    const char * const record_args[] = {
    "record", "-a", "-R", "-f", "-c", "1",
    "-e", "kmem:kmalloc",
    "-e", "kmem:kmalloc_node",
    "-e", "kmem:kfree",
    "-e", "kmem:kmem_cache_alloc",
    "-e", "kmem:kmem_cache_alloc_node",
    "-e", "kmem:kmem_cache_free",
    };
    unsigned int rec_argc, i, j;
    const char **rec_argv;

    rec_argc = ARRAY_SIZE(record_args) + argc - 1;
    rec_argv = calloc(rec_argc + 1, sizeof(char *));

    if (rec_argv == NULL)
        return -ENOMEM;

    for (i = 0; i < ARRAY_SIZE(record_args); i++)
        rec_argv[i] = strdup(record_args[i]);

    for (j = 1; j < (unsigned int)argc; j++, i++)
        rec_argv[i] = argv[j];

    return cmd_record(i, rec_argv, NULL);
}

int cmd_kmem(int argc, const char **argv, const char *prefix __maybe_unused)
{
    const char * const default_sort_order = "frag,hit,bytes";
    const char *input_name = NULL;
    const struct option kmem_options[] = {
    OPT_STRING('i', "input", &input_name, "file", "input file name"),
    OPT_CALLBACK_NOOPT(0, "caller", NULL, NULL,
               "show per-callsite statistics", parse_caller_opt),
    OPT_CALLBACK_NOOPT(0, "alloc", NULL, NULL,
               "show per-allocation statistics", parse_alloc_opt),
    OPT_CALLBACK('s', "sort", NULL, "key[,key2...]",
             "sort by keys: ptr, call_site, bytes, hit, pingpong, frag",
             parse_sort_opt),
    OPT_CALLBACK('l', "line", NULL, "num", "show n lines", parse_line_opt),
    OPT_BOOLEAN(0, "raw-ip", &raw_ip, "show raw ip instead of symbol"),
    OPT_END()
    };
    const char * const kmem_usage[] = {
        "perf kmem [<options>] {record|stat}",
        NULL
    };
    argc = parse_options(argc, argv, kmem_options, kmem_usage, 0);

    if (!argc)
        usage_with_options(kmem_usage, kmem_options);

    symbol__init();

    if (!strncmp(argv[0], "rec", 3)) {
        return __cmd_record(argc, argv);
    } else if (!strcmp(argv[0], "stat")) {
        if (setup_cpunode_map())
            return -1;

        if (list_empty(&caller_sort))
            setup_sorting(&caller_sort, default_sort_order);
        if (list_empty(&alloc_sort))
            setup_sorting(&alloc_sort, default_sort_order);

        return __cmd_kmem(input_name);
    } else
        usage_with_options(kmem_usage, kmem_options);

    return 0;
}