linux/tools/perf/util/mmap.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2011-2017, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
   4 *
   5 * Parts came from evlist.c builtin-{top,stat,record}.c, see those files for further
   6 * copyright notes.
   7 */
   8
   9#include <sys/mman.h>
  10#include <inttypes.h>
  11#include <asm/bug.h>
  12#include <linux/zalloc.h>
  13#include <stdlib.h>
  14#include <string.h>
  15#include <unistd.h> // sysconf()
  16#include <perf/mmap.h>
  17#ifdef HAVE_LIBNUMA_SUPPORT
  18#include <numaif.h>
  19#endif
  20#include "cpumap.h"
  21#include "debug.h"
  22#include "event.h"
  23#include "mmap.h"
  24#include "../perf.h"
  25#include <internal/lib.h> /* page_size */
  26#include <linux/bitmap.h>
  27
  28#define MASK_SIZE 1023
  29void mmap_cpu_mask__scnprintf(struct mmap_cpu_mask *mask, const char *tag)
  30{
  31        char buf[MASK_SIZE + 1];
  32        size_t len;
  33
  34        len = bitmap_scnprintf(mask->bits, mask->nbits, buf, MASK_SIZE);
  35        buf[len] = '\0';
  36        pr_debug("%p: %s mask[%zd]: %s\n", mask, tag, mask->nbits, buf);
  37}
  38
  39size_t mmap__mmap_len(struct mmap *map)
  40{
  41        return perf_mmap__mmap_len(&map->core);
  42}
  43
  44int __weak auxtrace_mmap__mmap(struct auxtrace_mmap *mm __maybe_unused,
  45                               struct auxtrace_mmap_params *mp __maybe_unused,
  46                               void *userpg __maybe_unused,
  47                               int fd __maybe_unused)
  48{
  49        return 0;
  50}
  51
  52void __weak auxtrace_mmap__munmap(struct auxtrace_mmap *mm __maybe_unused)
  53{
  54}
  55
  56void __weak auxtrace_mmap_params__init(struct auxtrace_mmap_params *mp __maybe_unused,
  57                                       off_t auxtrace_offset __maybe_unused,
  58                                       unsigned int auxtrace_pages __maybe_unused,
  59                                       bool auxtrace_overwrite __maybe_unused)
  60{
  61}
  62
  63void __weak auxtrace_mmap_params__set_idx(struct auxtrace_mmap_params *mp __maybe_unused,
  64                                          struct evlist *evlist __maybe_unused,
  65                                          int idx __maybe_unused,
  66                                          bool per_cpu __maybe_unused)
  67{
  68}
  69
  70#ifdef HAVE_AIO_SUPPORT
  71static int perf_mmap__aio_enabled(struct mmap *map)
  72{
  73        return map->aio.nr_cblocks > 0;
  74}
  75
  76#ifdef HAVE_LIBNUMA_SUPPORT
  77static int perf_mmap__aio_alloc(struct mmap *map, int idx)
  78{
  79        map->aio.data[idx] = mmap(NULL, mmap__mmap_len(map), PROT_READ|PROT_WRITE,
  80                                  MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
  81        if (map->aio.data[idx] == MAP_FAILED) {
  82                map->aio.data[idx] = NULL;
  83                return -1;
  84        }
  85
  86        return 0;
  87}
  88
  89static void perf_mmap__aio_free(struct mmap *map, int idx)
  90{
  91        if (map->aio.data[idx]) {
  92                munmap(map->aio.data[idx], mmap__mmap_len(map));
  93                map->aio.data[idx] = NULL;
  94        }
  95}
  96
  97static int perf_mmap__aio_bind(struct mmap *map, int idx, int cpu, int affinity)
  98{
  99        void *data;
 100        size_t mmap_len;
 101        unsigned long *node_mask;
 102        unsigned long node_index;
 103        int err = 0;
 104
 105        if (affinity != PERF_AFFINITY_SYS && cpu__max_node() > 1) {
 106                data = map->aio.data[idx];
 107                mmap_len = mmap__mmap_len(map);
 108                node_index = cpu__get_node(cpu);
 109                node_mask = bitmap_zalloc(node_index + 1);
 110                if (!node_mask) {
 111                        pr_err("Failed to allocate node mask for mbind: error %m\n");
 112                        return -1;
 113                }
 114                set_bit(node_index, node_mask);
 115                if (mbind(data, mmap_len, MPOL_BIND, node_mask, node_index + 1 + 1, 0)) {
 116                        pr_err("Failed to bind [%p-%p] AIO buffer to node %lu: error %m\n",
 117                                data, data + mmap_len, node_index);
 118                        err = -1;
 119                }
 120                bitmap_free(node_mask);
 121        }
 122
 123        return err;
 124}
 125#else /* !HAVE_LIBNUMA_SUPPORT */
 126static int perf_mmap__aio_alloc(struct mmap *map, int idx)
 127{
 128        map->aio.data[idx] = malloc(mmap__mmap_len(map));
 129        if (map->aio.data[idx] == NULL)
 130                return -1;
 131
 132        return 0;
 133}
 134
 135static void perf_mmap__aio_free(struct mmap *map, int idx)
 136{
 137        zfree(&(map->aio.data[idx]));
 138}
 139
 140static int perf_mmap__aio_bind(struct mmap *map __maybe_unused, int idx __maybe_unused,
 141                int cpu __maybe_unused, int affinity __maybe_unused)
 142{
 143        return 0;
 144}
 145#endif
 146
 147static int perf_mmap__aio_mmap(struct mmap *map, struct mmap_params *mp)
 148{
 149        int delta_max, i, prio, ret;
 150
 151        map->aio.nr_cblocks = mp->nr_cblocks;
 152        if (map->aio.nr_cblocks) {
 153                map->aio.aiocb = calloc(map->aio.nr_cblocks, sizeof(struct aiocb *));
 154                if (!map->aio.aiocb) {
 155                        pr_debug2("failed to allocate aiocb for data buffer, error %m\n");
 156                        return -1;
 157                }
 158                map->aio.cblocks = calloc(map->aio.nr_cblocks, sizeof(struct aiocb));
 159                if (!map->aio.cblocks) {
 160                        pr_debug2("failed to allocate cblocks for data buffer, error %m\n");
 161                        return -1;
 162                }
 163                map->aio.data = calloc(map->aio.nr_cblocks, sizeof(void *));
 164                if (!map->aio.data) {
 165                        pr_debug2("failed to allocate data buffer, error %m\n");
 166                        return -1;
 167                }
 168                delta_max = sysconf(_SC_AIO_PRIO_DELTA_MAX);
 169                for (i = 0; i < map->aio.nr_cblocks; ++i) {
 170                        ret = perf_mmap__aio_alloc(map, i);
 171                        if (ret == -1) {
 172                                pr_debug2("failed to allocate data buffer area, error %m");
 173                                return -1;
 174                        }
 175                        ret = perf_mmap__aio_bind(map, i, map->core.cpu, mp->affinity);
 176                        if (ret == -1)
 177                                return -1;
 178                        /*
 179                         * Use cblock.aio_fildes value different from -1
 180                         * to denote started aio write operation on the
 181                         * cblock so it requires explicit record__aio_sync()
 182                         * call prior the cblock may be reused again.
 183                         */
 184                        map->aio.cblocks[i].aio_fildes = -1;
 185                        /*
 186                         * Allocate cblocks with priority delta to have
 187                         * faster aio write system calls because queued requests
 188                         * are kept in separate per-prio queues and adding
 189                         * a new request will iterate thru shorter per-prio
 190                         * list. Blocks with numbers higher than
 191                         *  _SC_AIO_PRIO_DELTA_MAX go with priority 0.
 192                         */
 193                        prio = delta_max - i;
 194                        map->aio.cblocks[i].aio_reqprio = prio >= 0 ? prio : 0;
 195                }
 196        }
 197
 198        return 0;
 199}
 200
 201static void perf_mmap__aio_munmap(struct mmap *map)
 202{
 203        int i;
 204
 205        for (i = 0; i < map->aio.nr_cblocks; ++i)
 206                perf_mmap__aio_free(map, i);
 207        if (map->aio.data)
 208                zfree(&map->aio.data);
 209        zfree(&map->aio.cblocks);
 210        zfree(&map->aio.aiocb);
 211}
 212#else /* !HAVE_AIO_SUPPORT */
 213static int perf_mmap__aio_enabled(struct mmap *map __maybe_unused)
 214{
 215        return 0;
 216}
 217
 218static int perf_mmap__aio_mmap(struct mmap *map __maybe_unused,
 219                               struct mmap_params *mp __maybe_unused)
 220{
 221        return 0;
 222}
 223
 224static void perf_mmap__aio_munmap(struct mmap *map __maybe_unused)
 225{
 226}
 227#endif
 228
 229void mmap__munmap(struct mmap *map)
 230{
 231        bitmap_free(map->affinity_mask.bits);
 232
 233        perf_mmap__aio_munmap(map);
 234        if (map->data != NULL) {
 235                munmap(map->data, mmap__mmap_len(map));
 236                map->data = NULL;
 237        }
 238        auxtrace_mmap__munmap(&map->auxtrace_mmap);
 239}
 240
 241static void build_node_mask(int node, struct mmap_cpu_mask *mask)
 242{
 243        int c, cpu, nr_cpus;
 244        const struct perf_cpu_map *cpu_map = NULL;
 245
 246        cpu_map = cpu_map__online();
 247        if (!cpu_map)
 248                return;
 249
 250        nr_cpus = perf_cpu_map__nr(cpu_map);
 251        for (c = 0; c < nr_cpus; c++) {
 252                cpu = cpu_map->map[c]; /* map c index to online cpu index */
 253                if (cpu__get_node(cpu) == node)
 254                        set_bit(cpu, mask->bits);
 255        }
 256}
 257
 258static int perf_mmap__setup_affinity_mask(struct mmap *map, struct mmap_params *mp)
 259{
 260        map->affinity_mask.nbits = cpu__max_cpu();
 261        map->affinity_mask.bits = bitmap_zalloc(map->affinity_mask.nbits);
 262        if (!map->affinity_mask.bits)
 263                return -1;
 264
 265        if (mp->affinity == PERF_AFFINITY_NODE && cpu__max_node() > 1)
 266                build_node_mask(cpu__get_node(map->core.cpu), &map->affinity_mask);
 267        else if (mp->affinity == PERF_AFFINITY_CPU)
 268                set_bit(map->core.cpu, map->affinity_mask.bits);
 269
 270        return 0;
 271}
 272
 273int mmap__mmap(struct mmap *map, struct mmap_params *mp, int fd, int cpu)
 274{
 275        if (perf_mmap__mmap(&map->core, &mp->core, fd, cpu)) {
 276                pr_debug2("failed to mmap perf event ring buffer, error %d\n",
 277                          errno);
 278                return -1;
 279        }
 280
 281        if (mp->affinity != PERF_AFFINITY_SYS &&
 282                perf_mmap__setup_affinity_mask(map, mp)) {
 283                pr_debug2("failed to alloc mmap affinity mask, error %d\n",
 284                          errno);
 285                return -1;
 286        }
 287
 288        if (verbose == 2)
 289                mmap_cpu_mask__scnprintf(&map->affinity_mask, "mmap");
 290
 291        map->core.flush = mp->flush;
 292
 293        map->comp_level = mp->comp_level;
 294
 295        if (map->comp_level && !perf_mmap__aio_enabled(map)) {
 296                map->data = mmap(NULL, mmap__mmap_len(map), PROT_READ|PROT_WRITE,
 297                                 MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
 298                if (map->data == MAP_FAILED) {
 299                        pr_debug2("failed to mmap data buffer, error %d\n",
 300                                        errno);
 301                        map->data = NULL;
 302                        return -1;
 303                }
 304        }
 305
 306        if (auxtrace_mmap__mmap(&map->auxtrace_mmap,
 307                                &mp->auxtrace_mp, map->core.base, fd))
 308                return -1;
 309
 310        return perf_mmap__aio_mmap(map, mp);
 311}
 312
 313int perf_mmap__push(struct mmap *md, void *to,
 314                    int push(struct mmap *map, void *to, void *buf, size_t size))
 315{
 316        u64 head = perf_mmap__read_head(&md->core);
 317        unsigned char *data = md->core.base + page_size;
 318        unsigned long size;
 319        void *buf;
 320        int rc = 0;
 321
 322        rc = perf_mmap__read_init(&md->core);
 323        if (rc < 0)
 324                return (rc == -EAGAIN) ? 1 : -1;
 325
 326        size = md->core.end - md->core.start;
 327
 328        if ((md->core.start & md->core.mask) + size != (md->core.end & md->core.mask)) {
 329                buf = &data[md->core.start & md->core.mask];
 330                size = md->core.mask + 1 - (md->core.start & md->core.mask);
 331                md->core.start += size;
 332
 333                if (push(md, to, buf, size) < 0) {
 334                        rc = -1;
 335                        goto out;
 336                }
 337        }
 338
 339        buf = &data[md->core.start & md->core.mask];
 340        size = md->core.end - md->core.start;
 341        md->core.start += size;
 342
 343        if (push(md, to, buf, size) < 0) {
 344                rc = -1;
 345                goto out;
 346        }
 347
 348        md->core.prev = head;
 349        perf_mmap__consume(&md->core);
 350out:
 351        return rc;
 352}
 353