#include "builtin.h"
#include "perf.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 const char               *input_name;

static int                      alloc_flag;
static int                      caller_flag;

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

static bool                     raw_ip;

static char                     default_sort_order[] = "frag,hit,bytes";

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"

struct perf_kmem {
        struct perf_tool    tool;
        struct perf_session *session;
};

static void init_cpunode_map(void)
{
        FILE *fp;
        int i;

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

        if (fscanf(fp, "%d", &max_cpu_num) < 1)
                die("Failed to read 'kernel_max' from sysfs");
        max_cpu_num++;

        cpunode_map = calloc(max_cpu_num, sizeof(int));
        if (!cpunode_map)
                die("calloc");
        for (i = 0; i < max_cpu_num; i++)
                cpunode_map[i] = -1;
        fclose(fp);
}

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

        init_cpunode_map();

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

        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);
}

static void 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)
                        die("malloc");
                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;
}

static void 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)
                        die("malloc");
                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);
        }
}

static void process_alloc_event(void *data,
                                struct event_format *event,
                                int cpu,
                                u64 timestamp __used,
                                struct thread *thread __used,
                                int node)
{
        unsigned long call_site;
        unsigned long ptr;
        int bytes_req;
        int bytes_alloc;
        int node1, node2;

        ptr = raw_field_value(event, "ptr", data);
        call_site = raw_field_value(event, "call_site", data);
        bytes_req = raw_field_value(event, "bytes_req", data);
        bytes_alloc = raw_field_value(event, "bytes_alloc", data);

        insert_alloc_stat(call_site, ptr, bytes_req, bytes_alloc, cpu);
        insert_caller_stat(call_site, bytes_req, bytes_alloc);

        total_requested += bytes_req;
        total_allocated += bytes_alloc;

        if (node) {
                node1 = cpunode_map[cpu];
                node2 = raw_field_value(event, "node", data);
                if (node1 != node2)
                        nr_cross_allocs++;
        }
        nr_allocs++;
}

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 void process_free_event(void *data,
                               struct event_format *event,
                               int cpu,
                               u64 timestamp __used,
                               struct thread *thread __used)
{
        unsigned long ptr;
        struct alloc_stat *s_alloc, *s_caller;

        ptr = raw_field_value(event, "ptr", data);

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

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

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

static void process_raw_event(struct perf_tool *tool,
                              union perf_event *raw_event __used, void *data,
                              int cpu, u64 timestamp, struct thread *thread)
{
        struct perf_kmem *kmem = container_of(tool, struct perf_kmem, tool);
        struct event_format *event;
        int type;

        type = trace_parse_common_type(kmem->session->pevent, data);
        event = pevent_find_event(kmem->session->pevent, type);

        if (!strcmp(event->name, "kmalloc") ||
            !strcmp(event->name, "kmem_cache_alloc")) {
                process_alloc_event(data, event, cpu, timestamp, thread, 0);
                return;
        }

        if (!strcmp(event->name, "kmalloc_node") ||
            !strcmp(event->name, "kmem_cache_alloc_node")) {
                process_alloc_event(data, event, cpu, timestamp, thread, 1);
                return;
        }

        if (!strcmp(event->name, "kfree") ||
            !strcmp(event->name, "kmem_cache_free")) {
                process_free_event(data, event, cpu, timestamp, thread);
                return;
        }
}

static int process_sample_event(struct perf_tool *tool,
                                union perf_event *event,
                                struct perf_sample *sample,
                                struct perf_evsel *evsel __used,
                                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);

        process_raw_event(tool, event, sample->raw_data, sample->cpu,
                          sample->time, thread);

        return 0;
}

static struct perf_kmem perf_kmem = {
        .tool = {
                .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(void)
{
        int err = -EINVAL;
        struct perf_session *session;

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

        perf_kmem.session = session;

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

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

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

static const char * const kmem_usage[] = {
        "perf kmem [<options>] {record|stat}",
        NULL
};

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)
                                die("malloc");
                        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)
                die("strdup");

        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 __used,
                          const char *arg, int unset __used)
{
        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 __used,
                          const char *arg __used, int unset __used)
{
        caller_flag = (alloc_flag + 1);
        return 0;
}

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

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

static const char *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",
};

static int __cmd_record(int argc, const char **argv)
{
        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 __used)
{
        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")) {
                setup_cpunode_map();

                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();
        } else
                usage_with_options(kmem_usage, kmem_options);

        return 0;
}