1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * random utiility code, for bcache but in theory not specific to bcache 4 * 5 * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com> 6 * Copyright 2012 Google, Inc. 7 */ 8 9 #include <linux/bio.h> 10 #include <linux/blkdev.h> 11 #include <linux/console.h> 12 #include <linux/ctype.h> 13 #include <linux/debugfs.h> 14 #include <linux/freezer.h> 15 #include <linux/kthread.h> 16 #include <linux/log2.h> 17 #include <linux/math64.h> 18 #include <linux/percpu.h> 19 #include <linux/preempt.h> 20 #include <linux/random.h> 21 #include <linux/seq_file.h> 22 #include <linux/string.h> 23 #include <linux/types.h> 24 #include <linux/sched/clock.h> 25 26 #include "eytzinger.h" 27 #include "mean_and_variance.h" 28 #include "util.h" 29 30 static const char si_units[] = "?kMGTPEZY"; 31 32 /* string_get_size units: */ 33 static const char *const units_2[] = { 34 "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB" 35 }; 36 static const char *const units_10[] = { 37 "B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB" 38 }; 39 40 static int parse_u64(const char *cp, u64 *res) 41 { 42 const char *start = cp; 43 u64 v = 0; 44 45 if (!isdigit(*cp)) 46 return -EINVAL; 47 48 do { 49 if (v > U64_MAX / 10) 50 return -ERANGE; 51 v *= 10; 52 if (v > U64_MAX - (*cp - '0')) 53 return -ERANGE; 54 v += *cp - '0'; 55 cp++; 56 } while (isdigit(*cp)); 57 58 *res = v; 59 return cp - start; 60 } 61 62 static int bch2_pow(u64 n, u64 p, u64 *res) 63 { 64 *res = 1; 65 66 while (p--) { 67 if (*res > div_u64(U64_MAX, n)) 68 return -ERANGE; 69 *res *= n; 70 } 71 return 0; 72 } 73 74 static int parse_unit_suffix(const char *cp, u64 *res) 75 { 76 const char *start = cp; 77 u64 base = 1024; 78 unsigned u; 79 int ret; 80 81 if (*cp == ' ') 82 cp++; 83 84 for (u = 1; u < strlen(si_units); u++) 85 if (*cp == si_units[u]) { 86 cp++; 87 goto got_unit; 88 } 89 90 for (u = 0; u < ARRAY_SIZE(units_2); u++) 91 if (!strncmp(cp, units_2[u], strlen(units_2[u]))) { 92 cp += strlen(units_2[u]); 93 goto got_unit; 94 } 95 96 for (u = 0; u < ARRAY_SIZE(units_10); u++) 97 if (!strncmp(cp, units_10[u], strlen(units_10[u]))) { 98 cp += strlen(units_10[u]); 99 base = 1000; 100 goto got_unit; 101 } 102 103 *res = 1; 104 return 0; 105 got_unit: 106 ret = bch2_pow(base, u, res); 107 if (ret) 108 return ret; 109 110 return cp - start; 111 } 112 113 #define parse_or_ret(cp, _f) \ 114 do { \ 115 int _ret = _f; \ 116 if (_ret < 0) \ 117 return _ret; \ 118 cp += _ret; \ 119 } while (0) 120 121 static int __bch2_strtou64_h(const char *cp, u64 *res) 122 { 123 const char *start = cp; 124 u64 v = 0, b, f_n = 0, f_d = 1; 125 int ret; 126 127 parse_or_ret(cp, parse_u64(cp, &v)); 128 129 if (*cp == '.') { 130 cp++; 131 ret = parse_u64(cp, &f_n); 132 if (ret < 0) 133 return ret; 134 cp += ret; 135 136 ret = bch2_pow(10, ret, &f_d); 137 if (ret) 138 return ret; 139 } 140 141 parse_or_ret(cp, parse_unit_suffix(cp, &b)); 142 143 if (v > div_u64(U64_MAX, b)) 144 return -ERANGE; 145 v *= b; 146 147 if (f_n > div_u64(U64_MAX, b)) 148 return -ERANGE; 149 150 f_n = div_u64(f_n * b, f_d); 151 if (v + f_n < v) 152 return -ERANGE; 153 v += f_n; 154 155 *res = v; 156 return cp - start; 157 } 158 159 static int __bch2_strtoh(const char *cp, u64 *res, 160 u64 t_max, bool t_signed) 161 { 162 bool positive = *cp != '-'; 163 u64 v = 0; 164 165 if (*cp == '+' || *cp == '-') 166 cp++; 167 168 parse_or_ret(cp, __bch2_strtou64_h(cp, &v)); 169 170 if (*cp == '\n') 171 cp++; 172 if (*cp) 173 return -EINVAL; 174 175 if (positive) { 176 if (v > t_max) 177 return -ERANGE; 178 } else { 179 if (v && !t_signed) 180 return -ERANGE; 181 182 if (v > t_max + 1) 183 return -ERANGE; 184 v = -v; 185 } 186 187 *res = v; 188 return 0; 189 } 190 191 #define STRTO_H(name, type) \ 192 int bch2_ ## name ## _h(const char *cp, type *res) \ 193 { \ 194 u64 v = 0; \ 195 int ret = __bch2_strtoh(cp, &v, ANYSINT_MAX(type), \ 196 ANYSINT_MAX(type) != ((type) ~0ULL)); \ 197 *res = v; \ 198 return ret; \ 199 } 200 201 STRTO_H(strtoint, int) 202 STRTO_H(strtouint, unsigned int) 203 STRTO_H(strtoll, long long) 204 STRTO_H(strtoull, unsigned long long) 205 STRTO_H(strtou64, u64) 206 207 u64 bch2_read_flag_list(char *opt, const char * const list[]) 208 { 209 u64 ret = 0; 210 char *p, *s, *d = kstrdup(opt, GFP_KERNEL); 211 212 if (!d) 213 return -ENOMEM; 214 215 s = strim(d); 216 217 while ((p = strsep(&s, ","))) { 218 int flag = match_string(list, -1, p); 219 220 if (flag < 0) { 221 ret = -1; 222 break; 223 } 224 225 ret |= 1 << flag; 226 } 227 228 kfree(d); 229 230 return ret; 231 } 232 233 bool bch2_is_zero(const void *_p, size_t n) 234 { 235 const char *p = _p; 236 size_t i; 237 238 for (i = 0; i < n; i++) 239 if (p[i]) 240 return false; 241 return true; 242 } 243 244 void bch2_prt_u64_base2_nbits(struct printbuf *out, u64 v, unsigned nr_bits) 245 { 246 while (nr_bits) 247 prt_char(out, '0' + ((v >> --nr_bits) & 1)); 248 } 249 250 void bch2_prt_u64_base2(struct printbuf *out, u64 v) 251 { 252 bch2_prt_u64_base2_nbits(out, v, fls64(v) ?: 1); 253 } 254 255 void bch2_print_string_as_lines(const char *prefix, const char *lines) 256 { 257 const char *p; 258 259 if (!lines) { 260 printk("%s (null)\n", prefix); 261 return; 262 } 263 264 console_lock(); 265 while (1) { 266 p = strchrnul(lines, '\n'); 267 printk("%s%.*s\n", prefix, (int) (p - lines), lines); 268 if (!*p) 269 break; 270 lines = p + 1; 271 } 272 console_unlock(); 273 } 274 275 int bch2_save_backtrace(bch_stacktrace *stack, struct task_struct *task, unsigned skipnr, 276 gfp_t gfp) 277 { 278 #ifdef CONFIG_STACKTRACE 279 unsigned nr_entries = 0; 280 281 stack->nr = 0; 282 int ret = darray_make_room_gfp(stack, 32, gfp); 283 if (ret) 284 return ret; 285 286 if (!down_read_trylock(&task->signal->exec_update_lock)) 287 return -1; 288 289 do { 290 nr_entries = stack_trace_save_tsk(task, stack->data, stack->size, skipnr + 1); 291 } while (nr_entries == stack->size && 292 !(ret = darray_make_room_gfp(stack, stack->size * 2, gfp))); 293 294 stack->nr = nr_entries; 295 up_read(&task->signal->exec_update_lock); 296 297 return ret; 298 #else 299 return 0; 300 #endif 301 } 302 303 void bch2_prt_backtrace(struct printbuf *out, bch_stacktrace *stack) 304 { 305 darray_for_each(*stack, i) { 306 prt_printf(out, "[<0>] %pB", (void *) *i); 307 prt_newline(out); 308 } 309 } 310 311 int bch2_prt_task_backtrace(struct printbuf *out, struct task_struct *task, unsigned skipnr, gfp_t gfp) 312 { 313 bch_stacktrace stack = { 0 }; 314 int ret = bch2_save_backtrace(&stack, task, skipnr + 1, gfp); 315 316 bch2_prt_backtrace(out, &stack); 317 darray_exit(&stack); 318 return ret; 319 } 320 321 #ifndef __KERNEL__ 322 #include <time.h> 323 void bch2_prt_datetime(struct printbuf *out, time64_t sec) 324 { 325 time_t t = sec; 326 char buf[64]; 327 ctime_r(&t, buf); 328 strim(buf); 329 prt_str(out, buf); 330 } 331 #else 332 void bch2_prt_datetime(struct printbuf *out, time64_t sec) 333 { 334 char buf[64]; 335 snprintf(buf, sizeof(buf), "%ptT", &sec); 336 prt_u64(out, sec); 337 } 338 #endif 339 340 void bch2_pr_time_units(struct printbuf *out, u64 ns) 341 { 342 const struct time_unit *u = bch2_pick_time_units(ns); 343 344 prt_printf(out, "%llu %s", div_u64(ns, u->nsecs), u->name); 345 } 346 347 static void bch2_pr_time_units_aligned(struct printbuf *out, u64 ns) 348 { 349 const struct time_unit *u = bch2_pick_time_units(ns); 350 351 prt_printf(out, "%llu ", div64_u64(ns, u->nsecs)); 352 prt_tab_rjust(out); 353 prt_printf(out, "%s", u->name); 354 } 355 356 static inline void pr_name_and_units(struct printbuf *out, const char *name, u64 ns) 357 { 358 prt_str(out, name); 359 prt_tab(out); 360 bch2_pr_time_units_aligned(out, ns); 361 prt_newline(out); 362 } 363 364 #define TABSTOP_SIZE 12 365 366 void bch2_time_stats_to_text(struct printbuf *out, struct bch2_time_stats *stats) 367 { 368 struct quantiles *quantiles = time_stats_to_quantiles(stats); 369 s64 f_mean = 0, d_mean = 0; 370 u64 f_stddev = 0, d_stddev = 0; 371 372 if (stats->buffer) { 373 int cpu; 374 375 spin_lock_irq(&stats->lock); 376 for_each_possible_cpu(cpu) 377 __bch2_time_stats_clear_buffer(stats, per_cpu_ptr(stats->buffer, cpu)); 378 spin_unlock_irq(&stats->lock); 379 } 380 381 /* 382 * avoid divide by zero 383 */ 384 if (stats->freq_stats.n) { 385 f_mean = mean_and_variance_get_mean(stats->freq_stats); 386 f_stddev = mean_and_variance_get_stddev(stats->freq_stats); 387 d_mean = mean_and_variance_get_mean(stats->duration_stats); 388 d_stddev = mean_and_variance_get_stddev(stats->duration_stats); 389 } 390 391 printbuf_tabstop_push(out, out->indent + TABSTOP_SIZE); 392 prt_printf(out, "count:"); 393 prt_tab(out); 394 prt_printf(out, "%llu ", 395 stats->duration_stats.n); 396 printbuf_tabstop_pop(out); 397 prt_newline(out); 398 399 printbuf_tabstops_reset(out); 400 401 printbuf_tabstop_push(out, out->indent + 20); 402 printbuf_tabstop_push(out, TABSTOP_SIZE + 2); 403 printbuf_tabstop_push(out, 0); 404 printbuf_tabstop_push(out, TABSTOP_SIZE + 2); 405 406 prt_tab(out); 407 prt_printf(out, "since mount"); 408 prt_tab_rjust(out); 409 prt_tab(out); 410 prt_printf(out, "recent"); 411 prt_tab_rjust(out); 412 prt_newline(out); 413 414 printbuf_tabstops_reset(out); 415 printbuf_tabstop_push(out, out->indent + 20); 416 printbuf_tabstop_push(out, TABSTOP_SIZE); 417 printbuf_tabstop_push(out, 2); 418 printbuf_tabstop_push(out, TABSTOP_SIZE); 419 420 prt_printf(out, "duration of events"); 421 prt_newline(out); 422 printbuf_indent_add(out, 2); 423 424 pr_name_and_units(out, "min:", stats->min_duration); 425 pr_name_and_units(out, "max:", stats->max_duration); 426 pr_name_and_units(out, "total:", stats->total_duration); 427 428 prt_printf(out, "mean:"); 429 prt_tab(out); 430 bch2_pr_time_units_aligned(out, d_mean); 431 prt_tab(out); 432 bch2_pr_time_units_aligned(out, mean_and_variance_weighted_get_mean(stats->duration_stats_weighted, TIME_STATS_MV_WEIGHT)); 433 prt_newline(out); 434 435 prt_printf(out, "stddev:"); 436 prt_tab(out); 437 bch2_pr_time_units_aligned(out, d_stddev); 438 prt_tab(out); 439 bch2_pr_time_units_aligned(out, mean_and_variance_weighted_get_stddev(stats->duration_stats_weighted, TIME_STATS_MV_WEIGHT)); 440 441 printbuf_indent_sub(out, 2); 442 prt_newline(out); 443 444 prt_printf(out, "time between events"); 445 prt_newline(out); 446 printbuf_indent_add(out, 2); 447 448 pr_name_and_units(out, "min:", stats->min_freq); 449 pr_name_and_units(out, "max:", stats->max_freq); 450 451 prt_printf(out, "mean:"); 452 prt_tab(out); 453 bch2_pr_time_units_aligned(out, f_mean); 454 prt_tab(out); 455 bch2_pr_time_units_aligned(out, mean_and_variance_weighted_get_mean(stats->freq_stats_weighted, TIME_STATS_MV_WEIGHT)); 456 prt_newline(out); 457 458 prt_printf(out, "stddev:"); 459 prt_tab(out); 460 bch2_pr_time_units_aligned(out, f_stddev); 461 prt_tab(out); 462 bch2_pr_time_units_aligned(out, mean_and_variance_weighted_get_stddev(stats->freq_stats_weighted, TIME_STATS_MV_WEIGHT)); 463 464 printbuf_indent_sub(out, 2); 465 prt_newline(out); 466 467 printbuf_tabstops_reset(out); 468 469 if (quantiles) { 470 int i = eytzinger0_first(NR_QUANTILES); 471 const struct time_unit *u = 472 bch2_pick_time_units(quantiles->entries[i].m); 473 u64 last_q = 0; 474 475 prt_printf(out, "quantiles (%s):\t", u->name); 476 eytzinger0_for_each(i, NR_QUANTILES) { 477 bool is_last = eytzinger0_next(i, NR_QUANTILES) == -1; 478 479 u64 q = max(quantiles->entries[i].m, last_q); 480 prt_printf(out, "%llu ", div_u64(q, u->nsecs)); 481 if (is_last) 482 prt_newline(out); 483 last_q = q; 484 } 485 } 486 } 487 488 /* ratelimit: */ 489 490 /** 491 * bch2_ratelimit_delay() - return how long to delay until the next time to do 492 * some work 493 * @d: the struct bch_ratelimit to update 494 * Returns: the amount of time to delay by, in jiffies 495 */ 496 u64 bch2_ratelimit_delay(struct bch_ratelimit *d) 497 { 498 u64 now = local_clock(); 499 500 return time_after64(d->next, now) 501 ? nsecs_to_jiffies(d->next - now) 502 : 0; 503 } 504 505 /** 506 * bch2_ratelimit_increment() - increment @d by the amount of work done 507 * @d: the struct bch_ratelimit to update 508 * @done: the amount of work done, in arbitrary units 509 */ 510 void bch2_ratelimit_increment(struct bch_ratelimit *d, u64 done) 511 { 512 u64 now = local_clock(); 513 514 d->next += div_u64(done * NSEC_PER_SEC, d->rate); 515 516 if (time_before64(now + NSEC_PER_SEC, d->next)) 517 d->next = now + NSEC_PER_SEC; 518 519 if (time_after64(now - NSEC_PER_SEC * 2, d->next)) 520 d->next = now - NSEC_PER_SEC * 2; 521 } 522 523 /* pd controller: */ 524 525 /* 526 * Updates pd_controller. Attempts to scale inputed values to units per second. 527 * @target: desired value 528 * @actual: current value 529 * 530 * @sign: 1 or -1; 1 if increasing the rate makes actual go up, -1 if increasing 531 * it makes actual go down. 532 */ 533 void bch2_pd_controller_update(struct bch_pd_controller *pd, 534 s64 target, s64 actual, int sign) 535 { 536 s64 proportional, derivative, change; 537 538 unsigned long seconds_since_update = (jiffies - pd->last_update) / HZ; 539 540 if (seconds_since_update == 0) 541 return; 542 543 pd->last_update = jiffies; 544 545 proportional = actual - target; 546 proportional *= seconds_since_update; 547 proportional = div_s64(proportional, pd->p_term_inverse); 548 549 derivative = actual - pd->last_actual; 550 derivative = div_s64(derivative, seconds_since_update); 551 derivative = ewma_add(pd->smoothed_derivative, derivative, 552 (pd->d_term / seconds_since_update) ?: 1); 553 derivative = derivative * pd->d_term; 554 derivative = div_s64(derivative, pd->p_term_inverse); 555 556 change = proportional + derivative; 557 558 /* Don't increase rate if not keeping up */ 559 if (change > 0 && 560 pd->backpressure && 561 time_after64(local_clock(), 562 pd->rate.next + NSEC_PER_MSEC)) 563 change = 0; 564 565 change *= (sign * -1); 566 567 pd->rate.rate = clamp_t(s64, (s64) pd->rate.rate + change, 568 1, UINT_MAX); 569 570 pd->last_actual = actual; 571 pd->last_derivative = derivative; 572 pd->last_proportional = proportional; 573 pd->last_change = change; 574 pd->last_target = target; 575 } 576 577 void bch2_pd_controller_init(struct bch_pd_controller *pd) 578 { 579 pd->rate.rate = 1024; 580 pd->last_update = jiffies; 581 pd->p_term_inverse = 6000; 582 pd->d_term = 30; 583 pd->d_smooth = pd->d_term; 584 pd->backpressure = 1; 585 } 586 587 void bch2_pd_controller_debug_to_text(struct printbuf *out, struct bch_pd_controller *pd) 588 { 589 if (!out->nr_tabstops) 590 printbuf_tabstop_push(out, 20); 591 592 prt_printf(out, "rate:"); 593 prt_tab(out); 594 prt_human_readable_s64(out, pd->rate.rate); 595 prt_newline(out); 596 597 prt_printf(out, "target:"); 598 prt_tab(out); 599 prt_human_readable_u64(out, pd->last_target); 600 prt_newline(out); 601 602 prt_printf(out, "actual:"); 603 prt_tab(out); 604 prt_human_readable_u64(out, pd->last_actual); 605 prt_newline(out); 606 607 prt_printf(out, "proportional:"); 608 prt_tab(out); 609 prt_human_readable_s64(out, pd->last_proportional); 610 prt_newline(out); 611 612 prt_printf(out, "derivative:"); 613 prt_tab(out); 614 prt_human_readable_s64(out, pd->last_derivative); 615 prt_newline(out); 616 617 prt_printf(out, "change:"); 618 prt_tab(out); 619 prt_human_readable_s64(out, pd->last_change); 620 prt_newline(out); 621 622 prt_printf(out, "next io:"); 623 prt_tab(out); 624 prt_printf(out, "%llims", div64_s64(pd->rate.next - local_clock(), NSEC_PER_MSEC)); 625 prt_newline(out); 626 } 627 628 /* misc: */ 629 630 void bch2_bio_map(struct bio *bio, void *base, size_t size) 631 { 632 while (size) { 633 struct page *page = is_vmalloc_addr(base) 634 ? vmalloc_to_page(base) 635 : virt_to_page(base); 636 unsigned offset = offset_in_page(base); 637 unsigned len = min_t(size_t, PAGE_SIZE - offset, size); 638 639 BUG_ON(!bio_add_page(bio, page, len, offset)); 640 size -= len; 641 base += len; 642 } 643 } 644 645 int bch2_bio_alloc_pages(struct bio *bio, size_t size, gfp_t gfp_mask) 646 { 647 while (size) { 648 struct page *page = alloc_pages(gfp_mask, 0); 649 unsigned len = min_t(size_t, PAGE_SIZE, size); 650 651 if (!page) 652 return -ENOMEM; 653 654 if (unlikely(!bio_add_page(bio, page, len, 0))) { 655 __free_page(page); 656 break; 657 } 658 659 size -= len; 660 } 661 662 return 0; 663 } 664 665 size_t bch2_rand_range(size_t max) 666 { 667 size_t rand; 668 669 if (!max) 670 return 0; 671 672 do { 673 rand = get_random_long(); 674 rand &= roundup_pow_of_two(max) - 1; 675 } while (rand >= max); 676 677 return rand; 678 } 679 680 void memcpy_to_bio(struct bio *dst, struct bvec_iter dst_iter, const void *src) 681 { 682 struct bio_vec bv; 683 struct bvec_iter iter; 684 685 __bio_for_each_segment(bv, dst, iter, dst_iter) { 686 void *dstp = kmap_local_page(bv.bv_page); 687 688 memcpy(dstp + bv.bv_offset, src, bv.bv_len); 689 kunmap_local(dstp); 690 691 src += bv.bv_len; 692 } 693 } 694 695 void memcpy_from_bio(void *dst, struct bio *src, struct bvec_iter src_iter) 696 { 697 struct bio_vec bv; 698 struct bvec_iter iter; 699 700 __bio_for_each_segment(bv, src, iter, src_iter) { 701 void *srcp = kmap_local_page(bv.bv_page); 702 703 memcpy(dst, srcp + bv.bv_offset, bv.bv_len); 704 kunmap_local(srcp); 705 706 dst += bv.bv_len; 707 } 708 } 709 710 #if 0 711 void eytzinger1_test(void) 712 { 713 unsigned inorder, eytz, size; 714 715 pr_info("1 based eytzinger test:"); 716 717 for (size = 2; 718 size < 65536; 719 size++) { 720 unsigned extra = eytzinger1_extra(size); 721 722 if (!(size % 4096)) 723 pr_info("tree size %u", size); 724 725 BUG_ON(eytzinger1_prev(0, size) != eytzinger1_last(size)); 726 BUG_ON(eytzinger1_next(0, size) != eytzinger1_first(size)); 727 728 BUG_ON(eytzinger1_prev(eytzinger1_first(size), size) != 0); 729 BUG_ON(eytzinger1_next(eytzinger1_last(size), size) != 0); 730 731 inorder = 1; 732 eytzinger1_for_each(eytz, size) { 733 BUG_ON(__inorder_to_eytzinger1(inorder, size, extra) != eytz); 734 BUG_ON(__eytzinger1_to_inorder(eytz, size, extra) != inorder); 735 BUG_ON(eytz != eytzinger1_last(size) && 736 eytzinger1_prev(eytzinger1_next(eytz, size), size) != eytz); 737 738 inorder++; 739 } 740 } 741 } 742 743 void eytzinger0_test(void) 744 { 745 746 unsigned inorder, eytz, size; 747 748 pr_info("0 based eytzinger test:"); 749 750 for (size = 1; 751 size < 65536; 752 size++) { 753 unsigned extra = eytzinger0_extra(size); 754 755 if (!(size % 4096)) 756 pr_info("tree size %u", size); 757 758 BUG_ON(eytzinger0_prev(-1, size) != eytzinger0_last(size)); 759 BUG_ON(eytzinger0_next(-1, size) != eytzinger0_first(size)); 760 761 BUG_ON(eytzinger0_prev(eytzinger0_first(size), size) != -1); 762 BUG_ON(eytzinger0_next(eytzinger0_last(size), size) != -1); 763 764 inorder = 0; 765 eytzinger0_for_each(eytz, size) { 766 BUG_ON(__inorder_to_eytzinger0(inorder, size, extra) != eytz); 767 BUG_ON(__eytzinger0_to_inorder(eytz, size, extra) != inorder); 768 BUG_ON(eytz != eytzinger0_last(size) && 769 eytzinger0_prev(eytzinger0_next(eytz, size), size) != eytz); 770 771 inorder++; 772 } 773 } 774 } 775 776 static inline int cmp_u16(const void *_l, const void *_r, size_t size) 777 { 778 const u16 *l = _l, *r = _r; 779 780 return (*l > *r) - (*r - *l); 781 } 782 783 static void eytzinger0_find_test_val(u16 *test_array, unsigned nr, u16 search) 784 { 785 int i, c1 = -1, c2 = -1; 786 ssize_t r; 787 788 r = eytzinger0_find_le(test_array, nr, 789 sizeof(test_array[0]), 790 cmp_u16, &search); 791 if (r >= 0) 792 c1 = test_array[r]; 793 794 for (i = 0; i < nr; i++) 795 if (test_array[i] <= search && test_array[i] > c2) 796 c2 = test_array[i]; 797 798 if (c1 != c2) { 799 eytzinger0_for_each(i, nr) 800 pr_info("[%3u] = %12u", i, test_array[i]); 801 pr_info("find_le(%2u) -> [%2zi] = %2i should be %2i", 802 i, r, c1, c2); 803 } 804 } 805 806 void eytzinger0_find_test(void) 807 { 808 unsigned i, nr, allocated = 1 << 12; 809 u16 *test_array = kmalloc_array(allocated, sizeof(test_array[0]), GFP_KERNEL); 810 811 for (nr = 1; nr < allocated; nr++) { 812 pr_info("testing %u elems", nr); 813 814 get_random_bytes(test_array, nr * sizeof(test_array[0])); 815 eytzinger0_sort(test_array, nr, sizeof(test_array[0]), cmp_u16, NULL); 816 817 /* verify array is sorted correctly: */ 818 eytzinger0_for_each(i, nr) 819 BUG_ON(i != eytzinger0_last(nr) && 820 test_array[i] > test_array[eytzinger0_next(i, nr)]); 821 822 for (i = 0; i < U16_MAX; i += 1 << 12) 823 eytzinger0_find_test_val(test_array, nr, i); 824 825 for (i = 0; i < nr; i++) { 826 eytzinger0_find_test_val(test_array, nr, test_array[i] - 1); 827 eytzinger0_find_test_val(test_array, nr, test_array[i]); 828 eytzinger0_find_test_val(test_array, nr, test_array[i] + 1); 829 } 830 } 831 832 kfree(test_array); 833 } 834 #endif 835 836 /* 837 * Accumulate percpu counters onto one cpu's copy - only valid when access 838 * against any percpu counter is guarded against 839 */ 840 u64 *bch2_acc_percpu_u64s(u64 __percpu *p, unsigned nr) 841 { 842 u64 *ret; 843 int cpu; 844 845 /* access to pcpu vars has to be blocked by other locking */ 846 preempt_disable(); 847 ret = this_cpu_ptr(p); 848 preempt_enable(); 849 850 for_each_possible_cpu(cpu) { 851 u64 *i = per_cpu_ptr(p, cpu); 852 853 if (i != ret) { 854 acc_u64s(ret, i, nr); 855 memset(i, 0, nr * sizeof(u64)); 856 } 857 } 858 859 return ret; 860 } 861 862 void bch2_darray_str_exit(darray_str *d) 863 { 864 darray_for_each(*d, i) 865 kfree(*i); 866 darray_exit(d); 867 } 868 869 int bch2_split_devs(const char *_dev_name, darray_str *ret) 870 { 871 darray_init(ret); 872 873 char *dev_name, *s, *orig; 874 875 dev_name = orig = kstrdup(_dev_name, GFP_KERNEL); 876 if (!dev_name) 877 return -ENOMEM; 878 879 while ((s = strsep(&dev_name, ":"))) { 880 char *p = kstrdup(s, GFP_KERNEL); 881 if (!p) 882 goto err; 883 884 if (darray_push(ret, p)) { 885 kfree(p); 886 goto err; 887 } 888 } 889 890 kfree(orig); 891 return 0; 892 err: 893 bch2_darray_str_exit(ret); 894 kfree(orig); 895 return -ENOMEM; 896 } 897