mem-events.c

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// SPDX-License-Identifier: GPL-2.0
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <api/fs/fs.h>
#include <linux/kernel.h>
#include "mem-events.h"
#include "debug.h"
#include "symbol.h"
#include "sort.h"

unsigned int perf_mem_events__loads_ldlat = 30;

#define E(t, n, s) { .tag = t, .name = n, .sysfs_name = s }

struct perf_mem_event perf_mem_events[PERF_MEM_EVENTS__MAX] = {
    E("ldlat-loads",    "cpu/mem-loads,ldlat=%u/P", "mem-loads"),
    E("ldlat-stores",   "cpu/mem-stores/P",     "mem-stores"),
};
#undef E

#undef E

static char mem_loads_name[100];
static bool mem_loads_name__init;

char *perf_mem_events__name(int i)
{
    if (i == PERF_MEM_EVENTS__LOAD) {
        if (!mem_loads_name__init) {
            mem_loads_name__init = true;
            scnprintf(mem_loads_name, sizeof(mem_loads_name),
                  perf_mem_events[i].name,
                  perf_mem_events__loads_ldlat);
        }
        return mem_loads_name;
    }

    return (char *)perf_mem_events[i].name;
}

int perf_mem_events__parse(const char *str)
{
    char *tok, *saveptr = NULL;
    bool found = false;
    char *buf;
    int j;

    /* We need buffer that we know we can write to. */
    buf = malloc(strlen(str) + 1);
    if (!buf)
        return -ENOMEM;

    strcpy(buf, str);

    tok = strtok_r((char *)buf, ",", &saveptr);

    while (tok) {
        for (j = 0; j < PERF_MEM_EVENTS__MAX; j++) {
            struct perf_mem_event *e = &perf_mem_events[j];

            if (strstr(e->tag, tok))
                e->record = found = true;
        }

        tok = strtok_r(NULL, ",", &saveptr);
    }

    free(buf);

    if (found)
        return 0;

    pr_err("failed: event '%s' not found, use '-e list' to get list of available events\n", str);
    return -1;
}

int perf_mem_events__init(void)
{
    const char *mnt = sysfs__mount();
    bool found = false;
    int j;

    if (!mnt)
        return -ENOENT;

    for (j = 0; j < PERF_MEM_EVENTS__MAX; j++) {
        char path[PATH_MAX];
        struct perf_mem_event *e = &perf_mem_events[j];
        struct stat st;

        scnprintf(path, PATH_MAX, "%s/devices/cpu/events/%s",
              mnt, e->sysfs_name);

        if (!stat(path, &st))
            e->supported = found = true;
    }

    return found ? 0 : -ENOENT;
}

static const char * const tlb_access[] = {
    "N/A",
    "HIT",
    "MISS",
    "L1",
    "L2",
    "Walker",
    "Fault",
};

int perf_mem__tlb_scnprintf(char *out, size_t sz, struct mem_info *mem_info)
{
    size_t l = 0, i;
    u64 m = PERF_MEM_TLB_NA;
    u64 hit, miss;

    sz -= 1; /* -1 for null termination */
    out[0] = '\0';

    if (mem_info)
        m = mem_info->data_src.mem_dtlb;

    hit = m & PERF_MEM_TLB_HIT;
    miss = m & PERF_MEM_TLB_MISS;

    /* already taken care of */
    m &= ~(PERF_MEM_TLB_HIT|PERF_MEM_TLB_MISS);

    for (i = 0; m && i < ARRAY_SIZE(tlb_access); i++, m >>= 1) {
        if (!(m & 0x1))
            continue;
        if (l) {
            strcat(out, " or ");
            l += 4;
        }
        l += scnprintf(out + l, sz - l, tlb_access[i]);
    }
    if (*out == '\0')
        l += scnprintf(out, sz - l, "N/A");
    if (hit)
        l += scnprintf(out + l, sz - l, " hit");
    if (miss)
        l += scnprintf(out + l, sz - l, " miss");

    return l;
}

static const char * const mem_lvl[] = {
    "N/A",
    "HIT",
    "MISS",
    "L1",
    "LFB",
    "L2",
    "L3",
    "Local RAM",
    "Remote RAM (1 hop)",
    "Remote RAM (2 hops)",
    "Remote Cache (1 hop)",
    "Remote Cache (2 hops)",
    "I/O",
    "Uncached",
};

static const char * const mem_lvlnum[] = {
    [PERF_MEM_LVLNUM_ANY_CACHE] = "Any cache",
    [PERF_MEM_LVLNUM_LFB] = "LFB",
    [PERF_MEM_LVLNUM_RAM] = "RAM",
    [PERF_MEM_LVLNUM_PMEM] = "PMEM",
    [PERF_MEM_LVLNUM_NA] = "N/A",
};

int perf_mem__lvl_scnprintf(char *out, size_t sz, struct mem_info *mem_info)
{
    size_t i, l = 0;
    u64 m =  PERF_MEM_LVL_NA;
    u64 hit, miss;
    int printed;

    if (mem_info)
        m  = mem_info->data_src.mem_lvl;

    sz -= 1; /* -1 for null termination */
    out[0] = '\0';

    hit = m & PERF_MEM_LVL_HIT;
    miss = m & PERF_MEM_LVL_MISS;

    /* already taken care of */
    m &= ~(PERF_MEM_LVL_HIT|PERF_MEM_LVL_MISS);


    if (mem_info && mem_info->data_src.mem_remote) {
        strcat(out, "Remote ");
        l += 7;
    }

    printed = 0;
    for (i = 0; m && i < ARRAY_SIZE(mem_lvl); i++, m >>= 1) {
        if (!(m & 0x1))
            continue;
        if (printed++) {
            strcat(out, " or ");
            l += 4;
        }
        l += scnprintf(out + l, sz - l, mem_lvl[i]);
    }

    if (mem_info && mem_info->data_src.mem_lvl_num) {
        int lvl = mem_info->data_src.mem_lvl_num;
        if (printed++) {
            strcat(out, " or ");
            l += 4;
        }
        if (mem_lvlnum[lvl])
            l += scnprintf(out + l, sz - l, mem_lvlnum[lvl]);
        else
            l += scnprintf(out + l, sz - l, "L%d", lvl);
    }

    if (l == 0)
        l += scnprintf(out + l, sz - l, "N/A");
    if (hit)
        l += scnprintf(out + l, sz - l, " hit");
    if (miss)
        l += scnprintf(out + l, sz - l, " miss");

    return l;
}

static const char * const snoop_access[] = {
    "N/A",
    "None",
    "Hit",
    "Miss",
    "HitM",
};

int perf_mem__snp_scnprintf(char *out, size_t sz, struct mem_info *mem_info)
{
    size_t i, l = 0;
    u64 m = PERF_MEM_SNOOP_NA;

    sz -= 1; /* -1 for null termination */
    out[0] = '\0';

    if (mem_info)
        m = mem_info->data_src.mem_snoop;

    for (i = 0; m && i < ARRAY_SIZE(snoop_access); i++, m >>= 1) {
        if (!(m & 0x1))
            continue;
        if (l) {
            strcat(out, " or ");
            l += 4;
        }
        l += scnprintf(out + l, sz - l, snoop_access[i]);
    }
    if (mem_info &&
         (mem_info->data_src.mem_snoopx & PERF_MEM_SNOOPX_FWD)) {
        if (l) {
            strcat(out, " or ");
            l += 4;
        }
        l += scnprintf(out + l, sz - l, "Fwd");
    }

    if (*out == '\0')
        l += scnprintf(out, sz - l, "N/A");

    return l;
}

int perf_mem__lck_scnprintf(char *out, size_t sz, struct mem_info *mem_info)
{
    u64 mask = PERF_MEM_LOCK_NA;
    int l;

    if (mem_info)
        mask = mem_info->data_src.mem_lock;

    if (mask & PERF_MEM_LOCK_NA)
        l = scnprintf(out, sz, "N/A");
    else if (mask & PERF_MEM_LOCK_LOCKED)
        l = scnprintf(out, sz, "Yes");
    else
        l = scnprintf(out, sz, "No");

    return l;
}

int perf_script__meminfo_scnprintf(char *out, size_t sz, struct mem_info *mem_info)
{
    int i = 0;

    i += perf_mem__lvl_scnprintf(out, sz, mem_info);
    i += scnprintf(out + i, sz - i, "|SNP ");
    i += perf_mem__snp_scnprintf(out + i, sz - i, mem_info);
    i += scnprintf(out + i, sz - i, "|TLB ");
    i += perf_mem__tlb_scnprintf(out + i, sz - i, mem_info);
    i += scnprintf(out + i, sz - i, "|LCK ");
    i += perf_mem__lck_scnprintf(out + i, sz - i, mem_info);

    return i;
}

int c2c_decode_stats(struct c2c_stats *stats, struct mem_info *mi)
{
    union perf_mem_data_src *data_src = &mi->data_src;
    u64 daddr  = mi->daddr.addr;
    u64 op     = data_src->mem_op;
    u64 lvl    = data_src->mem_lvl;
    u64 snoop  = data_src->mem_snoop;
    u64 lock   = data_src->mem_lock;
    /*
     * Skylake might report unknown remote level via this
     * bit, consider it when evaluating remote HITMs.
     */
    bool mrem  = data_src->mem_remote;
    int err = 0;

#define HITM_INC(__f)       \
do {                \
    stats->__f++;       \
    stats->tot_hitm++;  \
} while (0)

#define P(a, b) PERF_MEM_##a##_##b

    stats->nr_entries++;

    if (lock & P(LOCK, LOCKED)) stats->locks++;

    if (op & P(OP, LOAD)) {
        /* load */
        stats->load++;

        if (!daddr) {
            stats->ld_noadrs++;
            return -1;
        }

        if (lvl & P(LVL, HIT)) {
            if (lvl & P(LVL, UNC)) stats->ld_uncache++;
            if (lvl & P(LVL, IO))  stats->ld_io++;
            if (lvl & P(LVL, LFB)) stats->ld_fbhit++;
            if (lvl & P(LVL, L1 )) stats->ld_l1hit++;
            if (lvl & P(LVL, L2 )) stats->ld_l2hit++;
            if (lvl & P(LVL, L3 )) {
                if (snoop & P(SNOOP, HITM))
                    HITM_INC(lcl_hitm);
                else
                    stats->ld_llchit++;
            }

            if (lvl & P(LVL, LOC_RAM)) {
                stats->lcl_dram++;
                if (snoop & P(SNOOP, HIT))
                    stats->ld_shared++;
                else
                    stats->ld_excl++;
            }

            if ((lvl & P(LVL, REM_RAM1)) ||
                (lvl & P(LVL, REM_RAM2)) ||
                 mrem) {
                stats->rmt_dram++;
                if (snoop & P(SNOOP, HIT))
                    stats->ld_shared++;
                else
                    stats->ld_excl++;
            }
        }

        if ((lvl & P(LVL, REM_CCE1)) ||
            (lvl & P(LVL, REM_CCE2)) ||
             mrem) {
            if (snoop & P(SNOOP, HIT))
                stats->rmt_hit++;
            else if (snoop & P(SNOOP, HITM))
                HITM_INC(rmt_hitm);
        }

        if ((lvl & P(LVL, MISS)))
            stats->ld_miss++;

    } else if (op & P(OP, STORE)) {
        /* store */
        stats->store++;

        if (!daddr) {
            stats->st_noadrs++;
            return -1;
        }

        if (lvl & P(LVL, HIT)) {
            if (lvl & P(LVL, UNC)) stats->st_uncache++;
            if (lvl & P(LVL, L1 )) stats->st_l1hit++;
        }
        if (lvl & P(LVL, MISS))
            if (lvl & P(LVL, L1)) stats->st_l1miss++;
    } else {
        /* unparsable data_src? */
        stats->noparse++;
        return -1;
    }

    if (!mi->daddr.map || !mi->iaddr.map) {
        stats->nomap++;
        return -1;
    }

#undef P
#undef HITM_INC
    return err;
}

void c2c_add_stats(struct c2c_stats *stats, struct c2c_stats *add)
{
    stats->nr_entries   += add->nr_entries;

    stats->locks        += add->locks;
    stats->store        += add->store;
    stats->st_uncache   += add->st_uncache;
    stats->st_noadrs    += add->st_noadrs;
    stats->st_l1hit     += add->st_l1hit;
    stats->st_l1miss    += add->st_l1miss;
    stats->load     += add->load;
    stats->ld_excl      += add->ld_excl;
    stats->ld_shared    += add->ld_shared;
    stats->ld_uncache   += add->ld_uncache;
    stats->ld_io        += add->ld_io;
    stats->ld_miss      += add->ld_miss;
    stats->ld_noadrs    += add->ld_noadrs;
    stats->ld_fbhit     += add->ld_fbhit;
    stats->ld_l1hit     += add->ld_l1hit;
    stats->ld_l2hit     += add->ld_l2hit;
    stats->ld_llchit    += add->ld_llchit;
    stats->lcl_hitm     += add->lcl_hitm;
    stats->rmt_hitm     += add->rmt_hitm;
    stats->tot_hitm     += add->tot_hitm;
    stats->rmt_hit      += add->rmt_hit;
    stats->lcl_dram     += add->lcl_dram;
    stats->rmt_dram     += add->rmt_dram;
    stats->nomap        += add->nomap;
    stats->noparse      += add->noparse;
}