builtin-kmem.c

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// SPDX-License-Identifier: GPL-2.0
#include "builtin.h"
#include "perf.h"

#include "util/evlist.h"
#include "util/evsel.h"
#include "util/util.h"
#include "util/config.h"
#include "util/symbol.h"
#include "util/thread.h"
#include "util/header.h"
#include "util/session.h"
#include "util/tool.h"
#include "util/callchain.h"
#include "util/time-utils.h"

#include <subcmd/parse-options.h>
#include "util/trace-event.h"
#include "util/data.h"
#include "util/cpumap.h"

#include "util/debug.h"

#include <linux/kernel.h>
#include <linux/rbtree.h>
#include <linux/string.h>
#include <errno.h>
#include <inttypes.h>
#include <locale.h>
#include <regex.h>

#include "sane_ctype.h"

static int  kmem_slab;
static int  kmem_page;

static long kmem_page_size;
static enum {
    KMEM_SLAB,
    KMEM_PAGE,
} kmem_default = KMEM_SLAB;  /* for backward compatibility */

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

static int          alloc_flag;
static int          caller_flag;

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

static bool         raw_ip;

struct alloc_stat {
    u64 call_site;
    u64 ptr;
    u64 bytes_req;
    u64 bytes_alloc;
    u64 last_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, total_freed;
static unsigned long nr_allocs, nr_cross_allocs;

/* filters for controlling start and stop of time of analysis */
static struct perf_time_interval ptime;
const char *time_str;

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;
    data->last_alloc = bytes_alloc;

    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 = cpu__get_node(sample->cpu),
            node2 = perf_evsel__intval(evsel, sample, "node");

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

    return ret;
}

static int ptr_cmp(void *, void *);
static int slab_callsite_cmp(void *, void *);

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;

    total_freed += s_alloc->last_alloc;

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

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

    return 0;
}

static u64 total_page_alloc_bytes;
static u64 total_page_free_bytes;
static u64 total_page_nomatch_bytes;
static u64 total_page_fail_bytes;
static unsigned long nr_page_allocs;
static unsigned long nr_page_frees;
static unsigned long nr_page_fails;
static unsigned long nr_page_nomatch;

static bool use_pfn;
static bool live_page;
static struct perf_session *kmem_session;

#define MAX_MIGRATE_TYPES  6
#define MAX_PAGE_ORDER     11

static int order_stats[MAX_PAGE_ORDER][MAX_MIGRATE_TYPES];

struct page_stat {
    struct rb_node  node;
    u64         page;
    u64         callsite;
    int         order;
    unsigned    gfp_flags;
    unsigned    migrate_type;
    u64     alloc_bytes;
    u64         free_bytes;
    int         nr_alloc;
    int         nr_free;
};

static struct rb_root page_live_tree;
static struct rb_root page_alloc_tree;
static struct rb_root page_alloc_sorted;
static struct rb_root page_caller_tree;
static struct rb_root page_caller_sorted;

struct alloc_func {
    u64 start;
    u64 end;
    char *name;
};

static int nr_alloc_funcs;
static struct alloc_func *alloc_func_list;

static int funcmp(const void *a, const void *b)
{
    const struct alloc_func *fa = a;
    const struct alloc_func *fb = b;

    if (fa->start > fb->start)
        return 1;
    else
        return -1;
}

static int callcmp(const void *a, const void *b)
{
    const struct alloc_func *fa = a;
    const struct alloc_func *fb = b;

    if (fb->start <= fa->start && fa->end < fb->end)
        return 0;

    if (fa->start > fb->start)
        return 1;
    else
        return -1;
}

static int build_alloc_func_list(void)
{
    int ret;
    struct map *kernel_map;
    struct symbol *sym;
    struct rb_node *node;
    struct alloc_func *func;
    struct machine *machine = &kmem_session->machines.host;
    regex_t alloc_func_regex;
    const char pattern[] = "^_?_?(alloc|get_free|get_zeroed)_pages?";

    ret = regcomp(&alloc_func_regex, pattern, REG_EXTENDED);
    if (ret) {
        char err[BUFSIZ];

        regerror(ret, &alloc_func_regex, err, sizeof(err));
        pr_err("Invalid regex: %s\n%s", pattern, err);
        return -EINVAL;
    }

    kernel_map = machine__kernel_map(machine);
    if (map__load(kernel_map) < 0) {
        pr_err("cannot load kernel map\n");
        return -ENOENT;
    }

    map__for_each_symbol(kernel_map, sym, node) {
        if (regexec(&alloc_func_regex, sym->name, 0, NULL, 0))
            continue;

        func = realloc(alloc_func_list,
                   (nr_alloc_funcs + 1) * sizeof(*func));
        if (func == NULL)
            return -ENOMEM;

        pr_debug("alloc func: %s\n", sym->name);
        func[nr_alloc_funcs].start = sym->start;
        func[nr_alloc_funcs].end   = sym->end;
        func[nr_alloc_funcs].name  = sym->name;

        alloc_func_list = func;
        nr_alloc_funcs++;
    }

    qsort(alloc_func_list, nr_alloc_funcs, sizeof(*func), funcmp);

    regfree(&alloc_func_regex);
    return 0;
}

/*
 * Find first non-memory allocation function from callchain.
 * The allocation functions are in the 'alloc_func_list'.
 */
static u64 find_callsite(struct perf_evsel *evsel, struct perf_sample *sample)
{
    struct addr_location al;
    struct machine *machine = &kmem_session->machines.host;
    struct callchain_cursor_node *node;

    if (alloc_func_list == NULL) {
        if (build_alloc_func_list() < 0)
            goto out;
    }

    al.thread = machine__findnew_thread(machine, sample->pid, sample->tid);
    sample__resolve_callchain(sample, &callchain_cursor, NULL, evsel, &al, 16);

    callchain_cursor_commit(&callchain_cursor);
    while (true) {
        struct alloc_func key, *caller;
        u64 addr;

        node = callchain_cursor_current(&callchain_cursor);
        if (node == NULL)
            break;

        key.start = key.end = node->ip;
        caller = bsearch(&key, alloc_func_list, nr_alloc_funcs,
                 sizeof(key), callcmp);
        if (!caller) {
            /* found */
            if (node->map)
                addr = map__unmap_ip(node->map, node->ip);
            else
                addr = node->ip;

            return addr;
        } else
            pr_debug3("skipping alloc function: %s\n", caller->name);

        callchain_cursor_advance(&callchain_cursor);
    }

out:
    pr_debug2("unknown callsite: %"PRIx64 "\n", sample->ip);
    return sample->ip;
}

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

static LIST_HEAD(page_alloc_sort_input);
static LIST_HEAD(page_caller_sort_input);

static struct page_stat *
__page_stat__findnew_page(struct page_stat *pstat, bool create)
{
    struct rb_node **node = &page_live_tree.rb_node;
    struct rb_node *parent = NULL;
    struct page_stat *data;

    while (*node) {
        s64 cmp;

        parent = *node;
        data = rb_entry(*node, struct page_stat, node);

        cmp = data->page - pstat->page;
        if (cmp < 0)
            node = &parent->rb_left;
        else if (cmp > 0)
            node = &parent->rb_right;
        else
            return data;
    }

    if (!create)
        return NULL;

    data = zalloc(sizeof(*data));
    if (data != NULL) {
        data->page = pstat->page;
        data->order = pstat->order;
        data->gfp_flags = pstat->gfp_flags;
        data->migrate_type = pstat->migrate_type;

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

    return data;
}

static struct page_stat *page_stat__find_page(struct page_stat *pstat)
{
    return __page_stat__findnew_page(pstat, false);
}

static struct page_stat *page_stat__findnew_page(struct page_stat *pstat)
{
    return __page_stat__findnew_page(pstat, true);
}

static struct page_stat *
__page_stat__findnew_alloc(struct page_stat *pstat, bool create)
{
    struct rb_node **node = &page_alloc_tree.rb_node;
    struct rb_node *parent = NULL;
    struct page_stat *data;
    struct sort_dimension *sort;

    while (*node) {
        int cmp = 0;

        parent = *node;
        data = rb_entry(*node, struct page_stat, node);

        list_for_each_entry(sort, &page_alloc_sort_input, list) {
            cmp = sort->cmp(pstat, data);
            if (cmp)
                break;
        }

        if (cmp < 0)
            node = &parent->rb_left;
        else if (cmp > 0)
            node = &parent->rb_right;
        else
            return data;
    }

    if (!create)
        return NULL;

    data = zalloc(sizeof(*data));
    if (data != NULL) {
        data->page = pstat->page;
        data->order = pstat->order;
        data->gfp_flags = pstat->gfp_flags;
        data->migrate_type = pstat->migrate_type;

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

    return data;
}

static struct page_stat *page_stat__find_alloc(struct page_stat *pstat)
{
    return __page_stat__findnew_alloc(pstat, false);
}

static struct page_stat *page_stat__findnew_alloc(struct page_stat *pstat)
{
    return __page_stat__findnew_alloc(pstat, true);
}

static struct page_stat *
__page_stat__findnew_caller(struct page_stat *pstat, bool create)
{
    struct rb_node **node = &page_caller_tree.rb_node;
    struct rb_node *parent = NULL;
    struct page_stat *data;
    struct sort_dimension *sort;

    while (*node) {
        int cmp = 0;

        parent = *node;
        data = rb_entry(*node, struct page_stat, node);

        list_for_each_entry(sort, &page_caller_sort_input, list) {
            cmp = sort->cmp(pstat, data);
            if (cmp)
                break;
        }

        if (cmp < 0)
            node = &parent->rb_left;
        else if (cmp > 0)
            node = &parent->rb_right;
        else
            return data;
    }

    if (!create)
        return NULL;

    data = zalloc(sizeof(*data));
    if (data != NULL) {
        data->callsite = pstat->callsite;
        data->order = pstat->order;
        data->gfp_flags = pstat->gfp_flags;
        data->migrate_type = pstat->migrate_type;

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

    return data;
}

static struct page_stat *page_stat__find_caller(struct page_stat *pstat)
{
    return __page_stat__findnew_caller(pstat, false);
}

static struct page_stat *page_stat__findnew_caller(struct page_stat *pstat)
{
    return __page_stat__findnew_caller(pstat, true);
}

static bool valid_page(u64 pfn_or_page)
{
    if (use_pfn && pfn_or_page == -1UL)
        return false;
    if (!use_pfn && pfn_or_page == 0)
        return false;
    return true;
}

struct gfp_flag {
    unsigned int flags;
    char *compact_str;
    char *human_readable;
};

static struct gfp_flag *gfps;
static int nr_gfps;

static int gfpcmp(const void *a, const void *b)
{
    const struct gfp_flag *fa = a;
    const struct gfp_flag *fb = b;

    return fa->flags - fb->flags;
}

/* see include/trace/events/mmflags.h */
static const struct {
    const char *original;
    const char *compact;
} gfp_compact_table[] = {
    { "GFP_TRANSHUGE",      "THP" },
    { "GFP_TRANSHUGE_LIGHT",    "THL" },
    { "GFP_HIGHUSER_MOVABLE",   "HUM" },
    { "GFP_HIGHUSER",       "HU" },
    { "GFP_USER",           "U" },
    { "GFP_KERNEL_ACCOUNT",     "KAC" },
    { "GFP_KERNEL",         "K" },
    { "GFP_NOFS",           "NF" },
    { "GFP_ATOMIC",         "A" },
    { "GFP_NOIO",           "NI" },
    { "GFP_NOWAIT",         "NW" },
    { "GFP_DMA",            "D" },
    { "__GFP_HIGHMEM",      "HM" },
    { "GFP_DMA32",          "D32" },
    { "__GFP_HIGH",         "H" },
    { "__GFP_ATOMIC",       "_A" },
    { "__GFP_IO",           "I" },
    { "__GFP_FS",           "F" },
    { "__GFP_NOWARN",       "NWR" },
    { "__GFP_RETRY_MAYFAIL",    "R" },
    { "__GFP_NOFAIL",       "NF" },
    { "__GFP_NORETRY",      "NR" },
    { "__GFP_COMP",         "C" },
    { "__GFP_ZERO",         "Z" },
    { "__GFP_NOMEMALLOC",       "NMA" },
    { "__GFP_MEMALLOC",     "MA" },
    { "__GFP_HARDWALL",     "HW" },
    { "__GFP_THISNODE",     "TN" },
    { "__GFP_RECLAIMABLE",      "RC" },
    { "__GFP_MOVABLE",      "M" },
    { "__GFP_ACCOUNT",      "AC" },
    { "__GFP_WRITE",        "WR" },
    { "__GFP_RECLAIM",      "R" },
    { "__GFP_DIRECT_RECLAIM",   "DR" },
    { "__GFP_KSWAPD_RECLAIM",   "KR" },
};

static size_t max_gfp_len;

static char *compact_gfp_flags(char *gfp_flags)
{
    char *orig_flags = strdup(gfp_flags);
    char *new_flags = NULL;
    char *str, *pos = NULL;
    size_t len = 0;

    if (orig_flags == NULL)
        return NULL;

    str = strtok_r(orig_flags, "|", &pos);
    while (str) {
        size_t i;
        char *new;
        const char *cpt;

        for (i = 0; i < ARRAY_SIZE(gfp_compact_table); i++) {
            if (strcmp(gfp_compact_table[i].original, str))
                continue;

            cpt = gfp_compact_table[i].compact;
            new = realloc(new_flags, len + strlen(cpt) + 2);
            if (new == NULL) {
                free(new_flags);
                return NULL;
            }

            new_flags = new;

            if (!len) {
                strcpy(new_flags, cpt);
            } else {
                strcat(new_flags, "|");
                strcat(new_flags, cpt);
                len++;
            }

            len += strlen(cpt);
        }

        str = strtok_r(NULL, "|", &pos);
    }

    if (max_gfp_len < len)
        max_gfp_len = len;

    free(orig_flags);
    return new_flags;
}

static char *compact_gfp_string(unsigned long gfp_flags)
{
    struct gfp_flag key = {
        .flags = gfp_flags,
    };
    struct gfp_flag *gfp;

    gfp = bsearch(&key, gfps, nr_gfps, sizeof(*gfps), gfpcmp);
    if (gfp)
        return gfp->compact_str;

    return NULL;
}

static int parse_gfp_flags(struct perf_evsel *evsel, struct perf_sample *sample,
               unsigned int gfp_flags)
{
    struct pevent_record record = {
        .cpu = sample->cpu,
        .data = sample->raw_data,
        .size = sample->raw_size,
    };
    struct trace_seq seq;
    char *str, *pos = NULL;

    if (nr_gfps) {
        struct gfp_flag key = {
            .flags = gfp_flags,
        };

        if (bsearch(&key, gfps, nr_gfps, sizeof(*gfps), gfpcmp))
            return 0;
    }

    trace_seq_init(&seq);
    pevent_event_info(&seq, evsel->tp_format, &record);

    str = strtok_r(seq.buffer, " ", &pos);
    while (str) {
        if (!strncmp(str, "gfp_flags=", 10)) {
            struct gfp_flag *new;

            new = realloc(gfps, (nr_gfps + 1) * sizeof(*gfps));
            if (new == NULL)
                return -ENOMEM;

            gfps = new;
            new += nr_gfps++;

            new->flags = gfp_flags;
            new->human_readable = strdup(str + 10);
            new->compact_str = compact_gfp_flags(str + 10);
            if (!new->human_readable || !new->compact_str)
                return -ENOMEM;

            qsort(gfps, nr_gfps, sizeof(*gfps), gfpcmp);
        }

        str = strtok_r(NULL, " ", &pos);
    }

    trace_seq_destroy(&seq);
    return 0;
}

static int perf_evsel__process_page_alloc_event(struct perf_evsel *evsel,
                        struct perf_sample *sample)
{
    u64 page;
    unsigned int order = perf_evsel__intval(evsel, sample, "order");
    unsigned int gfp_flags = perf_evsel__intval(evsel, sample, "gfp_flags");
    unsigned int migrate_type = perf_evsel__intval(evsel, sample,
                               "migratetype");
    u64 bytes = kmem_page_size << order;
    u64 callsite;
    struct page_stat *pstat;
    struct page_stat this = {
        .order = order,
        .gfp_flags = gfp_flags,
        .migrate_type = migrate_type,
    };

    if (use_pfn)
        page = perf_evsel__intval(evsel, sample, "pfn");
    else
        page = perf_evsel__intval(evsel, sample, "page");

    nr_page_allocs++;
    total_page_alloc_bytes += bytes;

    if (!valid_page(page)) {
        nr_page_fails++;
        total_page_fail_bytes += bytes;

        return 0;
    }

    if (parse_gfp_flags(evsel, sample, gfp_flags) < 0)
        return -1;

    callsite = find_callsite(evsel, sample);

    /*
     * This is to find the current page (with correct gfp flags and
     * migrate type) at free event.
     */
    this.page = page;
    pstat = page_stat__findnew_page(&this);
    if (pstat == NULL)
        return -ENOMEM;

    pstat->nr_alloc++;
    pstat->alloc_bytes += bytes;
    pstat->callsite = callsite;

    if (!live_page) {
        pstat = page_stat__findnew_alloc(&this);
        if (pstat == NULL)
            return -ENOMEM;

        pstat->nr_alloc++;
        pstat->alloc_bytes += bytes;
        pstat->callsite = callsite;
    }

    this.callsite = callsite;
    pstat = page_stat__findnew_caller(&this);
    if (pstat == NULL)
        return -ENOMEM;

    pstat->nr_alloc++;
    pstat->alloc_bytes += bytes;

    order_stats[order][migrate_type]++;

    return 0;
}

static int perf_evsel__process_page_free_event(struct perf_evsel *evsel,
                        struct perf_sample *sample)
{
    u64 page;
    unsigned int order = perf_evsel__intval(evsel, sample, "order");
    u64 bytes = kmem_page_size << order;
    struct page_stat *pstat;
    struct page_stat this = {
        .order = order,
    };

    if (use_pfn)
        page = perf_evsel__intval(evsel, sample, "pfn");
    else
        page = perf_evsel__intval(evsel, sample, "page");

    nr_page_frees++;
    total_page_free_bytes += bytes;

    this.page = page;
    pstat = page_stat__find_page(&this);
    if (pstat == NULL) {
        pr_debug2("missing free at page %"PRIx64" (order: %d)\n",
              page, order);

        nr_page_nomatch++;
        total_page_nomatch_bytes += bytes;

        return 0;
    }

    this.gfp_flags = pstat->gfp_flags;
    this.migrate_type = pstat->migrate_type;
    this.callsite = pstat->callsite;

    rb_erase(&pstat->node, &page_live_tree);
    free(pstat);

    if (live_page) {
        order_stats[this.order][this.migrate_type]--;
    } else {
        pstat = page_stat__find_alloc(&this);
        if (pstat == NULL)
            return -ENOMEM;

        pstat->nr_free++;
        pstat->free_bytes += bytes;
    }

    pstat = page_stat__find_caller(&this);
    if (pstat == NULL)
        return -ENOENT;

    pstat->nr_free++;
    pstat->free_bytes += bytes;

    if (live_page) {
        pstat->nr_alloc--;
        pstat->alloc_bytes -= bytes;

        if (pstat->nr_alloc == 0) {
            rb_erase(&pstat->node, &page_caller_tree);
            free(pstat);
        }
    }

    return 0;
}

static bool perf_kmem__skip_sample(struct perf_sample *sample)
{
    /* skip sample based on time? */
    if (perf_time__skip_sample(&ptime, sample->time))
        return true;

    return false;
}

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)
{
    int err = 0;
    struct thread *thread = machine__findnew_thread(machine, sample->pid,
                            sample->tid);

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

    if (perf_kmem__skip_sample(sample))
        return 0;

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

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

    thread__put(thread);

    return err;
}

static struct perf_tool perf_kmem = {
    .sample      = process_sample_event,
    .comm        = perf_event__process_comm,
    .mmap        = perf_event__process_mmap,
    .mmap2       = perf_event__process_mmap2,
    .namespaces  = perf_event__process_namespaces,
    .ordered_events  = 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_slab_result(struct rb_root *root,
                struct perf_session *session,
                int n_lines, int is_caller)
{
    struct rb_node *next;
    struct machine *machine = &session->machines.host;

    printf("%.105s\n", graph_dotted_line);
    printf(" %-34s |",  is_caller ? "Callsite": "Alloc Ptr");
    printf(" Total_alloc/Per | Total_req/Per   | Hit      | Ping-pong | Frag\n");
    printf("%.105s\n", graph_dotted_line);

    next = rb_first(root);

    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_symbol(machine, addr, &map);
        } 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 | %9lu | %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("%.105s\n", graph_dotted_line);
}

static const char * const migrate_type_str[] = {
    "UNMOVABL",
    "RECLAIM",
    "MOVABLE",
    "RESERVED",
    "CMA/ISLT",
    "UNKNOWN",
};

static void __print_page_alloc_result(struct perf_session *session, int n_lines)
{
    struct rb_node *next = rb_first(&page_alloc_sorted);
    struct machine *machine = &session->machines.host;
    const char *format;
    int gfp_len = max(strlen("GFP flags"), max_gfp_len);

    printf("\n%.105s\n", graph_dotted_line);
    printf(" %-16s | %5s alloc (KB) | Hits      | Order | Mig.type | %-*s | Callsite\n",
           use_pfn ? "PFN" : "Page", live_page ? "Live" : "Total",
           gfp_len, "GFP flags");
    printf("%.105s\n", graph_dotted_line);

    if (use_pfn)
        format = " %16llu | %'16llu | %'9d | %5d | %8s | %-*s | %s\n";
    else
        format = " %016llx | %'16llu | %'9d | %5d | %8s | %-*s | %s\n";

    while (next && n_lines--) {
        struct page_stat *data;
        struct symbol *sym;
        struct map *map;
        char buf[32];
        char *caller = buf;

        data = rb_entry(next, struct page_stat, node);
        sym = machine__find_kernel_symbol(machine, data->callsite, &map);
        if (sym)
            caller = sym->name;
        else
            scnprintf(buf, sizeof(buf), "%"PRIx64, data->callsite);

        printf(format, (unsigned long long)data->page,
               (unsigned long long)data->alloc_bytes / 1024,
               data->nr_alloc, data->order,
               migrate_type_str[data->migrate_type],
               gfp_len, compact_gfp_string(data->gfp_flags), caller);

        next = rb_next(next);
    }

    if (n_lines == -1) {
        printf(" ...              | ...              | ...       | ...   | ...      | %-*s | ...\n",
               gfp_len, "...");
    }

    printf("%.105s\n", graph_dotted_line);
}

static void __print_page_caller_result(struct perf_session *session, int n_lines)
{
    struct rb_node *next = rb_first(&page_caller_sorted);
    struct machine *machine = &session->machines.host;
    int gfp_len = max(strlen("GFP flags"), max_gfp_len);

    printf("\n%.105s\n", graph_dotted_line);
    printf(" %5s alloc (KB) | Hits      | Order | Mig.type | %-*s | Callsite\n",
           live_page ? "Live" : "Total", gfp_len, "GFP flags");
    printf("%.105s\n", graph_dotted_line);

    while (next && n_lines--) {
        struct page_stat *data;
        struct symbol *sym;
        struct map *map;
        char buf[32];
        char *caller = buf;

        data = rb_entry(next, struct page_stat, node);
        sym = machine__find_kernel_symbol(machine, data->callsite, &map);
        if (sym)
            caller = sym->name;
        else
            scnprintf(buf, sizeof(buf), "%"PRIx64, data->callsite);

        printf(" %'16llu | %'9d | %5d | %8s | %-*s | %s\n",
               (unsigned long long)data->alloc_bytes / 1024,
               data->nr_alloc, data->order,
               migrate_type_str[data->migrate_type],
               gfp_len, compact_gfp_string(data->gfp_flags), caller);

        next = rb_next(next);
    }

    if (n_lines == -1) {
        printf(" ...              | ...       | ...   | ...      | %-*s | ...\n",
               gfp_len, "...");
    }

    printf("%.105s\n", graph_dotted_line);
}

static void print_gfp_flags(void)
{
    int i;

    printf("#\n");
    printf("# GFP flags\n");
    printf("# ---------\n");
    for (i = 0; i < nr_gfps; i++) {
        printf("# %08x: %*s: %s\n", gfps[i].flags,
               (int) max_gfp_len, gfps[i].compact_str,
               gfps[i].human_readable);
    }
}

static void print_slab_summary(void)
{
    printf("\nSUMMARY (SLAB allocator)");
    printf("\n========================\n");
    printf("Total bytes requested: %'lu\n", total_requested);
    printf("Total bytes allocated: %'lu\n", total_allocated);
    printf("Total bytes freed:     %'lu\n", total_freed);
    if (total_allocated > total_freed) {
        printf("Net total bytes allocated: %'lu\n",
        total_allocated - total_freed);
    }
    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_page_summary(void)
{
    int o, m;
    u64 nr_alloc_freed = nr_page_frees - nr_page_nomatch;
    u64 total_alloc_freed_bytes = total_page_free_bytes - total_page_nomatch_bytes;

    printf("\nSUMMARY (page allocator)");
    printf("\n========================\n");
    printf("%-30s: %'16lu   [ %'16"PRIu64" KB ]\n", "Total allocation requests",
           nr_page_allocs, total_page_alloc_bytes / 1024);
    printf("%-30s: %'16lu   [ %'16"PRIu64" KB ]\n", "Total free requests",
           nr_page_frees, total_page_free_bytes / 1024);
    printf("\n");

    printf("%-30s: %'16"PRIu64"   [ %'16"PRIu64" KB ]\n", "Total alloc+freed requests",
           nr_alloc_freed, (total_alloc_freed_bytes) / 1024);
    printf("%-30s: %'16"PRIu64"   [ %'16"PRIu64" KB ]\n", "Total alloc-only requests",
           nr_page_allocs - nr_alloc_freed,
           (total_page_alloc_bytes - total_alloc_freed_bytes) / 1024);
    printf("%-30s: %'16lu   [ %'16"PRIu64" KB ]\n", "Total free-only requests",
           nr_page_nomatch, total_page_nomatch_bytes / 1024);
    printf("\n");

    printf("%-30s: %'16lu   [ %'16"PRIu64" KB ]\n", "Total allocation failures",
           nr_page_fails, total_page_fail_bytes / 1024);
    printf("\n");

    printf("%5s  %12s  %12s  %12s  %12s  %12s\n", "Order",  "Unmovable",
           "Reclaimable", "Movable", "Reserved", "CMA/Isolated");
    printf("%.5s  %.12s  %.12s  %.12s  %.12s  %.12s\n", graph_dotted_line,
           graph_dotted_line, graph_dotted_line, graph_dotted_line,
           graph_dotted_line, graph_dotted_line);

    for (o = 0; o < MAX_PAGE_ORDER; o++) {
        printf("%5d", o);
        for (m = 0; m < MAX_MIGRATE_TYPES - 1; m++) {
            if (order_stats[o][m])
                printf("  %'12d", order_stats[o][m]);
            else
                printf("  %12c", '.');
        }
        printf("\n");
    }
}

static void print_slab_result(struct perf_session *session)
{
    if (caller_flag)
        __print_slab_result(&root_caller_sorted, session, caller_lines, 1);
    if (alloc_flag)
        __print_slab_result(&root_alloc_sorted, session, alloc_lines, 0);
    print_slab_summary();
}

static void print_page_result(struct perf_session *session)
{
    if (caller_flag || alloc_flag)
        print_gfp_flags();
    if (caller_flag)
        __print_page_caller_result(session, caller_lines);
    if (alloc_flag)
        __print_page_alloc_result(session, alloc_lines);
    print_page_summary();
}

static void print_result(struct perf_session *session)
{
    if (kmem_slab)
        print_slab_result(session);
    if (kmem_page)
        print_page_result(session);
}

static LIST_HEAD(slab_caller_sort);
static LIST_HEAD(slab_alloc_sort);
static LIST_HEAD(page_caller_sort);
static LIST_HEAD(page_alloc_sort);

static void sort_slab_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_slab_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_slab_insert(root_sorted, data, sort_list);
    }
}

static void sort_page_insert(struct rb_root *root, struct page_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 page_stat *this;
        int cmp = 0;

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

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

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

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

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

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

        rb_erase(node, root);
        data = rb_entry(node, struct page_stat, node);
        sort_page_insert(root_sorted, data, sort_list);
    }
}

static void sort_result(void)
{
    if (kmem_slab) {
        __sort_slab_result(&root_alloc_stat, &root_alloc_sorted,
                   &slab_alloc_sort);
        __sort_slab_result(&root_caller_stat, &root_caller_sorted,
                   &slab_caller_sort);
    }
    if (kmem_page) {
        if (live_page)
            __sort_page_result(&page_live_tree, &page_alloc_sorted,
                       &page_alloc_sort);
        else
            __sort_page_result(&page_alloc_tree, &page_alloc_sorted,
                       &page_alloc_sort);

        __sort_page_result(&page_caller_tree, &page_caller_sorted,
                   &page_caller_sort);
    }
}

static int __cmd_kmem(struct perf_session *session)
{
    int err = -EINVAL;
    struct perf_evsel *evsel;
    const struct perf_evsel_str_handler kmem_tracepoints[] = {
        /* slab allocator */
        { "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, },
        /* page allocator */
        { "kmem:mm_page_alloc",     perf_evsel__process_page_alloc_event, },
        { "kmem:mm_page_free",      perf_evsel__process_page_free_event, },
    };

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

    if (perf_session__set_tracepoints_handlers(session, kmem_tracepoints)) {
        pr_err("Initializing perf session tracepoint handlers failed\n");
        goto out;
    }

    evlist__for_each_entry(session->evlist, evsel) {
        if (!strcmp(perf_evsel__name(evsel), "kmem:mm_page_alloc") &&
            perf_evsel__field(evsel, "pfn")) {
            use_pfn = true;
            break;
        }
    }

    setup_pager();
    err = perf_session__process_events(session);
    if (err != 0) {
        pr_err("error during process events: %d\n", err);
        goto out;
    }
    sort_result();
    print_result(session);
out:
    return err;
}

/* slab sort keys */
static int ptr_cmp(void *a, void *b)
{
    struct alloc_stat *l = a;
    struct alloc_stat *r = b;

    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 slab_callsite_cmp(void *a, void *b)
{
    struct alloc_stat *l = a;
    struct alloc_stat *r = b;

    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    = slab_callsite_cmp,
};

static int hit_cmp(void *a, void *b)
{
    struct alloc_stat *l = a;
    struct alloc_stat *r = b;

    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(void *a, void *b)
{
    struct alloc_stat *l = a;
    struct alloc_stat *r = b;

    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(void *a, void *b)
{
    double x, y;
    struct alloc_stat *l = a;
    struct alloc_stat *r = b;

    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(void *a, void *b)
{
    struct alloc_stat *l = a;
    struct alloc_stat *r = b;

    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,
};

/* page sort keys */
static int page_cmp(void *a, void *b)
{
    struct page_stat *l = a;
    struct page_stat *r = b;

    if (l->page < r->page)
        return -1;
    else if (l->page > r->page)
        return 1;
    return 0;
}

static struct sort_dimension page_sort_dimension = {
    .name   = "page",
    .cmp    = page_cmp,
};

static int page_callsite_cmp(void *a, void *b)
{
    struct page_stat *l = a;
    struct page_stat *r = b;

    if (l->callsite < r->callsite)
        return -1;
    else if (l->callsite > r->callsite)
        return 1;
    return 0;
}

static struct sort_dimension page_callsite_sort_dimension = {
    .name   = "callsite",
    .cmp    = page_callsite_cmp,
};

static int page_hit_cmp(void *a, void *b)
{
    struct page_stat *l = a;
    struct page_stat *r = b;

    if (l->nr_alloc < r->nr_alloc)
        return -1;
    else if (l->nr_alloc > r->nr_alloc)
        return 1;
    return 0;
}

static struct sort_dimension page_hit_sort_dimension = {
    .name   = "hit",
    .cmp    = page_hit_cmp,
};

static int page_bytes_cmp(void *a, void *b)
{
    struct page_stat *l = a;
    struct page_stat *r = b;

    if (l->alloc_bytes < r->alloc_bytes)
        return -1;
    else if (l->alloc_bytes > r->alloc_bytes)
        return 1;
    return 0;
}

static struct sort_dimension page_bytes_sort_dimension = {
    .name   = "bytes",
    .cmp    = page_bytes_cmp,
};

static int page_order_cmp(void *a, void *b)
{
    struct page_stat *l = a;
    struct page_stat *r = b;

    if (l->order < r->order)
        return -1;
    else if (l->order > r->order)
        return 1;
    return 0;
}

static struct sort_dimension page_order_sort_dimension = {
    .name   = "order",
    .cmp    = page_order_cmp,
};

static int migrate_type_cmp(void *a, void *b)
{
    struct page_stat *l = a;
    struct page_stat *r = b;

    /* for internal use to find free'd page */
    if (l->migrate_type == -1U)
        return 0;

    if (l->migrate_type < r->migrate_type)
        return -1;
    else if (l->migrate_type > r->migrate_type)
        return 1;
    return 0;
}

static struct sort_dimension migrate_type_sort_dimension = {
    .name   = "migtype",
    .cmp    = migrate_type_cmp,
};

static int gfp_flags_cmp(void *a, void *b)
{
    struct page_stat *l = a;
    struct page_stat *r = b;

    /* for internal use to find free'd page */
    if (l->gfp_flags == -1U)
        return 0;

    if (l->gfp_flags < r->gfp_flags)
        return -1;
    else if (l->gfp_flags > r->gfp_flags)
        return 1;
    return 0;
}

static struct sort_dimension gfp_flags_sort_dimension = {
    .name   = "gfp",
    .cmp    = gfp_flags_cmp,
};

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

static struct sort_dimension *page_sorts[] = {
    &page_sort_dimension,
    &page_callsite_sort_dimension,
    &page_hit_sort_dimension,
    &page_bytes_sort_dimension,
    &page_order_sort_dimension,
    &migrate_type_sort_dimension,
    &gfp_flags_sort_dimension,
};

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

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

    return -1;
}

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

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

    return -1;
}

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

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

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

    free(str);
    return 0;
}

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

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

    while (true) {
        tok = strsep(&pos, ",");
        if (!tok)
            break;
        if (page_sort_dimension__add(tok, sort_list) < 0) {
            pr_err("Unknown page --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 (kmem_page > kmem_slab ||
        (kmem_page == 0 && kmem_slab == 0 && kmem_default == KMEM_PAGE)) {
        if (caller_flag > alloc_flag)
            return setup_page_sorting(&page_caller_sort, arg);
        else
            return setup_page_sorting(&page_alloc_sort, arg);
    } else {
        if (caller_flag > alloc_flag)
            return setup_slab_sorting(&slab_caller_sort, arg);
        else
            return setup_slab_sorting(&slab_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_slab_opt(const struct option *opt __maybe_unused,
              const char *arg __maybe_unused,
              int unset __maybe_unused)
{
    kmem_slab = (kmem_page + 1);
    return 0;
}

static int parse_page_opt(const struct option *opt __maybe_unused,
              const char *arg __maybe_unused,
              int unset __maybe_unused)
{
    kmem_page = (kmem_slab + 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", "-c", "1",
    };
    const char * const slab_events[] = {
    "-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",
    };
    const char * const page_events[] = {
    "-e", "kmem:mm_page_alloc",
    "-e", "kmem:mm_page_free",
    };
    unsigned int rec_argc, i, j;
    const char **rec_argv;

    rec_argc = ARRAY_SIZE(record_args) + argc - 1;
    if (kmem_slab)
        rec_argc += ARRAY_SIZE(slab_events);
    if (kmem_page)
        rec_argc += ARRAY_SIZE(page_events) + 1; /* for -g */

    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]);

    if (kmem_slab) {
        for (j = 0; j < ARRAY_SIZE(slab_events); j++, i++)
            rec_argv[i] = strdup(slab_events[j]);
    }
    if (kmem_page) {
        rec_argv[i++] = strdup("-g");

        for (j = 0; j < ARRAY_SIZE(page_events); j++, i++)
            rec_argv[i] = strdup(page_events[j]);
    }

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

    return cmd_record(i, rec_argv);
}

static int kmem_config(const char *var, const char *value, void *cb __maybe_unused)
{
    if (!strcmp(var, "kmem.default")) {
        if (!strcmp(value, "slab"))
            kmem_default = KMEM_SLAB;
        else if (!strcmp(value, "page"))
            kmem_default = KMEM_PAGE;
        else
            pr_err("invalid default value ('slab' or 'page' required): %s\n",
                   value);
        return 0;
    }

    return 0;
}

int cmd_kmem(int argc, const char **argv)
{
    const char * const default_slab_sort = "frag,hit,bytes";
    const char * const default_page_sort = "bytes,hit";
    struct perf_data data = {
        .mode = PERF_DATA_MODE_READ,
    };
    const struct option kmem_options[] = {
    OPT_STRING('i', "input", &input_name, "file", "input file name"),
    OPT_INCR('v', "verbose", &verbose,
            "be more verbose (show symbol address, etc)"),
    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, callsite, bytes, hit, pingpong, frag, "
             "page, order, migtype, gfp", 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_BOOLEAN('f', "force", &data.force, "don't complain, do it"),
    OPT_CALLBACK_NOOPT(0, "slab", NULL, NULL, "Analyze slab allocator",
               parse_slab_opt),
    OPT_CALLBACK_NOOPT(0, "page", NULL, NULL, "Analyze page allocator",
               parse_page_opt),
    OPT_BOOLEAN(0, "live", &live_page, "Show live page stat"),
    OPT_STRING(0, "time", &time_str, "str",
           "Time span of interest (start,stop)"),
    OPT_END()
    };
    const char *const kmem_subcommands[] = { "record", "stat", NULL };
    const char *kmem_usage[] = {
        NULL,
        NULL
    };
    struct perf_session *session;
    const char errmsg[] = "No %s allocation events found.  Have you run 'perf kmem record --%s'?\n";
    int ret = perf_config(kmem_config, NULL);

    if (ret)
        return ret;

    argc = parse_options_subcommand(argc, argv, kmem_options,
                    kmem_subcommands, kmem_usage, 0);

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

    if (kmem_slab == 0 && kmem_page == 0) {
        if (kmem_default == KMEM_SLAB)
            kmem_slab = 1;
        else
            kmem_page = 1;
    }

    if (!strncmp(argv[0], "rec", 3)) {
        symbol__init(NULL);
        return __cmd_record(argc, argv);
    }

    data.file.path = input_name;

    kmem_session = session = perf_session__new(&data, false, &perf_kmem);
    if (session == NULL)
        return -1;

    ret = -1;

    if (kmem_slab) {
        if (!perf_evlist__find_tracepoint_by_name(session->evlist,
                              "kmem:kmalloc")) {
            pr_err(errmsg, "slab", "slab");
            goto out_delete;
        }
    }

    if (kmem_page) {
        struct perf_evsel *evsel;

        evsel = perf_evlist__find_tracepoint_by_name(session->evlist,
                                 "kmem:mm_page_alloc");
        if (evsel == NULL) {
            pr_err(errmsg, "page", "page");
            goto out_delete;
        }

        kmem_page_size = pevent_get_page_size(evsel->tp_format->pevent);
        symbol_conf.use_callchain = true;
    }

    symbol__init(&session->header.env);

    if (perf_time__parse_str(&ptime, time_str) != 0) {
        pr_err("Invalid time string\n");
        ret = -EINVAL;
        goto out_delete;
    }

    if (!strcmp(argv[0], "stat")) {
        setlocale(LC_ALL, "");

        if (cpu__setup_cpunode_map())
            goto out_delete;

        if (list_empty(&slab_caller_sort))
            setup_slab_sorting(&slab_caller_sort, default_slab_sort);
        if (list_empty(&slab_alloc_sort))
            setup_slab_sorting(&slab_alloc_sort, default_slab_sort);
        if (list_empty(&page_caller_sort))
            setup_page_sorting(&page_caller_sort, default_page_sort);
        if (list_empty(&page_alloc_sort))
            setup_page_sorting(&page_alloc_sort, default_page_sort);

        if (kmem_page) {
            setup_page_sorting(&page_alloc_sort_input,
                       "page,order,migtype,gfp");
            setup_page_sorting(&page_caller_sort_input,
                       "callsite,order,migtype,gfp");
        }
        ret = __cmd_kmem(session);
    } else
        usage_with_options(kmem_usage, kmem_options);

out_delete:
    perf_session__delete(session);

    return ret;
}