1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * random utility 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 - ''))
53 return -ERANGE;
54 v += *cp - '';
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, '' + ((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 static void __bch2_print_string_as_lines(const char *prefix, const char *lines,
256 bool nonblocking)
257 {
258 bool locked = false;
259 const char *p;
260
261 if (!lines) {
262 printk("%s (null)\n", prefix);
263 return;
264 }
265
266 if (!nonblocking) {
267 console_lock();
268 locked = true;
269 } else {
270 locked = console_trylock();
271 }
272
273 while (1) {
274 p = strchrnul(lines, '\n');
275 printk("%s%.*s\n", prefix, (int) (p - lines), lines);
276 if (!*p)
277 break;
278 lines = p + 1;
279 }
280 if (locked)
281 console_unlock();
282 }
283
284 void bch2_print_string_as_lines(const char *prefix, const char *lines)
285 {
286 return __bch2_print_string_as_lines(prefix, lines, false);
287 }
288
289 void bch2_print_string_as_lines_nonblocking(const char *prefix, const char *lines)
290 {
291 return __bch2_print_string_as_lines(prefix, lines, true);
292 }
293
294 int bch2_save_backtrace(bch_stacktrace *stack, struct task_struct *task, unsigned skipnr,
295 gfp_t gfp)
296 {
297 #ifdef CONFIG_STACKTRACE
298 unsigned nr_entries = 0;
299
300 stack->nr = 0;
301 int ret = darray_make_room_gfp(stack, 32, gfp);
302 if (ret)
303 return ret;
304
305 if (!down_read_trylock(&task->signal->exec_update_lock))
306 return -1;
307
308 do {
309 nr_entries = stack_trace_save_tsk(task, stack->data, stack->size, skipnr + 1);
310 } while (nr_entries == stack->size &&
311 !(ret = darray_make_room_gfp(stack, stack->size * 2, gfp)));
312
313 stack->nr = nr_entries;
314 up_read(&task->signal->exec_update_lock);
315
316 return ret;
317 #else
318 return 0;
319 #endif
320 }
321
322 void bch2_prt_backtrace(struct printbuf *out, bch_stacktrace *stack)
323 {
324 darray_for_each(*stack, i) {
325 prt_printf(out, "[<0>] %pB", (void *) *i);
326 prt_newline(out);
327 }
328 }
329
330 int bch2_prt_task_backtrace(struct printbuf *out, struct task_struct *task, unsigned skipnr, gfp_t gfp)
331 {
332 bch_stacktrace stack = { 0 };
333 int ret = bch2_save_backtrace(&stack, task, skipnr + 1, gfp);
334
335 bch2_prt_backtrace(out, &stack);
336 darray_exit(&stack);
337 return ret;
338 }
339
340 #ifndef __KERNEL__
341 #include <time.h>
342 void bch2_prt_datetime(struct printbuf *out, time64_t sec)
343 {
344 time_t t = sec;
345 char buf[64];
346 ctime_r(&t, buf);
347 strim(buf);
348 prt_str(out, buf);
349 }
350 #else
351 void bch2_prt_datetime(struct printbuf *out, time64_t sec)
352 {
353 char buf[64];
354 snprintf(buf, sizeof(buf), "%ptT", &sec);
355 prt_u64(out, sec);
356 }
357 #endif
358
359 void bch2_pr_time_units(struct printbuf *out, u64 ns)
360 {
361 const struct time_unit *u = bch2_pick_time_units(ns);
362
363 prt_printf(out, "%llu %s", div_u64(ns, u->nsecs), u->name);
364 }
365
366 static void bch2_pr_time_units_aligned(struct printbuf *out, u64 ns)
367 {
368 const struct time_unit *u = bch2_pick_time_units(ns);
369
370 prt_printf(out, "%llu \r%s", div64_u64(ns, u->nsecs), u->name);
371 }
372
373 static inline void pr_name_and_units(struct printbuf *out, const char *name, u64 ns)
374 {
375 prt_printf(out, "%s\t", name);
376 bch2_pr_time_units_aligned(out, ns);
377 prt_newline(out);
378 }
379
380 #define TABSTOP_SIZE 12
381
382 void bch2_time_stats_to_text(struct printbuf *out, struct bch2_time_stats *stats)
383 {
384 struct quantiles *quantiles = time_stats_to_quantiles(stats);
385 s64 f_mean = 0, d_mean = 0;
386 u64 f_stddev = 0, d_stddev = 0;
387
388 if (stats->buffer) {
389 int cpu;
390
391 spin_lock_irq(&stats->lock);
392 for_each_possible_cpu(cpu)
393 __bch2_time_stats_clear_buffer(stats, per_cpu_ptr(stats->buffer, cpu));
394 spin_unlock_irq(&stats->lock);
395 }
396
397 /*
398 * avoid divide by zero
399 */
400 if (stats->freq_stats.n) {
401 f_mean = mean_and_variance_get_mean(stats->freq_stats);
402 f_stddev = mean_and_variance_get_stddev(stats->freq_stats);
403 d_mean = mean_and_variance_get_mean(stats->duration_stats);
404 d_stddev = mean_and_variance_get_stddev(stats->duration_stats);
405 }
406
407 printbuf_tabstop_push(out, out->indent + TABSTOP_SIZE);
408 prt_printf(out, "count:\t%llu\n", stats->duration_stats.n);
409 printbuf_tabstop_pop(out);
410
411 printbuf_tabstops_reset(out);
412
413 printbuf_tabstop_push(out, out->indent + 20);
414 printbuf_tabstop_push(out, TABSTOP_SIZE + 2);
415 printbuf_tabstop_push(out, 0);
416 printbuf_tabstop_push(out, TABSTOP_SIZE + 2);
417
418 prt_printf(out, "\tsince mount\r\trecent\r\n");
419 prt_printf(out, "recent");
420
421 printbuf_tabstops_reset(out);
422 printbuf_tabstop_push(out, out->indent + 20);
423 printbuf_tabstop_push(out, TABSTOP_SIZE);
424 printbuf_tabstop_push(out, 2);
425 printbuf_tabstop_push(out, TABSTOP_SIZE);
426
427 prt_printf(out, "duration of events\n");
428 printbuf_indent_add(out, 2);
429
430 pr_name_and_units(out, "min:", stats->min_duration);
431 pr_name_and_units(out, "max:", stats->max_duration);
432 pr_name_and_units(out, "total:", stats->total_duration);
433
434 prt_printf(out, "mean:\t");
435 bch2_pr_time_units_aligned(out, d_mean);
436 prt_tab(out);
437 bch2_pr_time_units_aligned(out, mean_and_variance_weighted_get_mean(stats->duration_stats_weighted, TIME_STATS_MV_WEIGHT));
438 prt_newline(out);
439
440 prt_printf(out, "stddev:\t");
441 bch2_pr_time_units_aligned(out, d_stddev);
442 prt_tab(out);
443 bch2_pr_time_units_aligned(out, mean_and_variance_weighted_get_stddev(stats->duration_stats_weighted, TIME_STATS_MV_WEIGHT));
444
445 printbuf_indent_sub(out, 2);
446 prt_newline(out);
447
448 prt_printf(out, "time between events\n");
449 printbuf_indent_add(out, 2);
450
451 pr_name_and_units(out, "min:", stats->min_freq);
452 pr_name_and_units(out, "max:", stats->max_freq);
453
454 prt_printf(out, "mean:\t");
455 bch2_pr_time_units_aligned(out, f_mean);
456 prt_tab(out);
457 bch2_pr_time_units_aligned(out, mean_and_variance_weighted_get_mean(stats->freq_stats_weighted, TIME_STATS_MV_WEIGHT));
458 prt_newline(out);
459
460 prt_printf(out, "stddev:\t");
461 bch2_pr_time_units_aligned(out, f_stddev);
462 prt_tab(out);
463 bch2_pr_time_units_aligned(out, mean_and_variance_weighted_get_stddev(stats->freq_stats_weighted, TIME_STATS_MV_WEIGHT));
464
465 printbuf_indent_sub(out, 2);
466 prt_newline(out);
467
468 printbuf_tabstops_reset(out);
469
470 if (quantiles) {
471 int i = eytzinger0_first(NR_QUANTILES);
472 const struct time_unit *u =
473 bch2_pick_time_units(quantiles->entries[i].m);
474 u64 last_q = 0;
475
476 prt_printf(out, "quantiles (%s):\t", u->name);
477 eytzinger0_for_each(i, NR_QUANTILES) {
478 bool is_last = eytzinger0_next(i, NR_QUANTILES) == -1;
479
480 u64 q = max(quantiles->entries[i].m, last_q);
481 prt_printf(out, "%llu ", div_u64(q, u->nsecs));
482 if (is_last)
483 prt_newline(out);
484 last_q = q;
485 }
486 }
487 }
488
489 /* ratelimit: */
490
491 /**
492 * bch2_ratelimit_delay() - return how long to delay until the next time to do
493 * some work
494 * @d: the struct bch_ratelimit to update
495 * Returns: the amount of time to delay by, in jiffies
496 */
497 u64 bch2_ratelimit_delay(struct bch_ratelimit *d)
498 {
499 u64 now = local_clock();
500
501 return time_after64(d->next, now)
502 ? nsecs_to_jiffies(d->next - now)
503 : 0;
504 }
505
506 /**
507 * bch2_ratelimit_increment() - increment @d by the amount of work done
508 * @d: the struct bch_ratelimit to update
509 * @done: the amount of work done, in arbitrary units
510 */
511 void bch2_ratelimit_increment(struct bch_ratelimit *d, u64 done)
512 {
513 u64 now = local_clock();
514
515 d->next += div_u64(done * NSEC_PER_SEC, d->rate);
516
517 if (time_before64(now + NSEC_PER_SEC, d->next))
518 d->next = now + NSEC_PER_SEC;
519
520 if (time_after64(now - NSEC_PER_SEC * 2, d->next))
521 d->next = now - NSEC_PER_SEC * 2;
522 }
523
524 /* pd controller: */
525
526 /*
527 * Updates pd_controller. Attempts to scale inputed values to units per second.
528 * @target: desired value
529 * @actual: current value
530 *
531 * @sign: 1 or -1; 1 if increasing the rate makes actual go up, -1 if increasing
532 * it makes actual go down.
533 */
534 void bch2_pd_controller_update(struct bch_pd_controller *pd,
535 s64 target, s64 actual, int sign)
536 {
537 s64 proportional, derivative, change;
538
539 unsigned long seconds_since_update = (jiffies - pd->last_update) / HZ;
540
541 if (seconds_since_update == 0)
542 return;
543
544 pd->last_update = jiffies;
545
546 proportional = actual - target;
547 proportional *= seconds_since_update;
548 proportional = div_s64(proportional, pd->p_term_inverse);
549
550 derivative = actual - pd->last_actual;
551 derivative = div_s64(derivative, seconds_since_update);
552 derivative = ewma_add(pd->smoothed_derivative, derivative,
553 (pd->d_term / seconds_since_update) ?: 1);
554 derivative = derivative * pd->d_term;
555 derivative = div_s64(derivative, pd->p_term_inverse);
556
557 change = proportional + derivative;
558
559 /* Don't increase rate if not keeping up */
560 if (change > 0 &&
561 pd->backpressure &&
562 time_after64(local_clock(),
563 pd->rate.next + NSEC_PER_MSEC))
564 change = 0;
565
566 change *= (sign * -1);
567
568 pd->rate.rate = clamp_t(s64, (s64) pd->rate.rate + change,
569 1, UINT_MAX);
570
571 pd->last_actual = actual;
572 pd->last_derivative = derivative;
573 pd->last_proportional = proportional;
574 pd->last_change = change;
575 pd->last_target = target;
576 }
577
578 void bch2_pd_controller_init(struct bch_pd_controller *pd)
579 {
580 pd->rate.rate = 1024;
581 pd->last_update = jiffies;
582 pd->p_term_inverse = 6000;
583 pd->d_term = 30;
584 pd->d_smooth = pd->d_term;
585 pd->backpressure = 1;
586 }
587
588 void bch2_pd_controller_debug_to_text(struct printbuf *out, struct bch_pd_controller *pd)
589 {
590 if (!out->nr_tabstops)
591 printbuf_tabstop_push(out, 20);
592
593 prt_printf(out, "rate:\t");
594 prt_human_readable_s64(out, pd->rate.rate);
595 prt_newline(out);
596
597 prt_printf(out, "target:\t");
598 prt_human_readable_u64(out, pd->last_target);
599 prt_newline(out);
600
601 prt_printf(out, "actual:\t");
602 prt_human_readable_u64(out, pd->last_actual);
603 prt_newline(out);
604
605 prt_printf(out, "proportional:\t");
606 prt_human_readable_s64(out, pd->last_proportional);
607 prt_newline(out);
608
609 prt_printf(out, "derivative:\t");
610 prt_human_readable_s64(out, pd->last_derivative);
611 prt_newline(out);
612
613 prt_printf(out, "change:\t");
614 prt_human_readable_s64(out, pd->last_change);
615 prt_newline(out);
616
617 prt_printf(out, "next io:\t%llims\n", div64_s64(pd->rate.next - local_clock(), NSEC_PER_MSEC));
618 }
619
620 /* misc: */
621
622 void bch2_bio_map(struct bio *bio, void *base, size_t size)
623 {
624 while (size) {
625 struct page *page = is_vmalloc_addr(base)
626 ? vmalloc_to_page(base)
627 : virt_to_page(base);
628 unsigned offset = offset_in_page(base);
629 unsigned len = min_t(size_t, PAGE_SIZE - offset, size);
630
631 BUG_ON(!bio_add_page(bio, page, len, offset));
632 size -= len;
633 base += len;
634 }
635 }
636
637 int bch2_bio_alloc_pages(struct bio *bio, size_t size, gfp_t gfp_mask)
638 {
639 while (size) {
640 struct page *page = alloc_pages(gfp_mask, 0);
641 unsigned len = min_t(size_t, PAGE_SIZE, size);
642
643 if (!page)
644 return -ENOMEM;
645
646 if (unlikely(!bio_add_page(bio, page, len, 0))) {
647 __free_page(page);
648 break;
649 }
650
651 size -= len;
652 }
653
654 return 0;
655 }
656
657 size_t bch2_rand_range(size_t max)
658 {
659 size_t rand;
660
661 if (!max)
662 return 0;
663
664 do {
665 rand = get_random_long();
666 rand &= roundup_pow_of_two(max) - 1;
667 } while (rand >= max);
668
669 return rand;
670 }
671
672 void memcpy_to_bio(struct bio *dst, struct bvec_iter dst_iter, const void *src)
673 {
674 struct bio_vec bv;
675 struct bvec_iter iter;
676
677 __bio_for_each_segment(bv, dst, iter, dst_iter) {
678 void *dstp = kmap_local_page(bv.bv_page);
679
680 memcpy(dstp + bv.bv_offset, src, bv.bv_len);
681 kunmap_local(dstp);
682
683 src += bv.bv_len;
684 }
685 }
686
687 void memcpy_from_bio(void *dst, struct bio *src, struct bvec_iter src_iter)
688 {
689 struct bio_vec bv;
690 struct bvec_iter iter;
691
692 __bio_for_each_segment(bv, src, iter, src_iter) {
693 void *srcp = kmap_local_page(bv.bv_page);
694
695 memcpy(dst, srcp + bv.bv_offset, bv.bv_len);
696 kunmap_local(srcp);
697
698 dst += bv.bv_len;
699 }
700 }
701
702 #if 0
703 void eytzinger1_test(void)
704 {
705 unsigned inorder, eytz, size;
706
707 pr_info("1 based eytzinger test:");
708
709 for (size = 2;
710 size < 65536;
711 size++) {
712 unsigned extra = eytzinger1_extra(size);
713
714 if (!(size % 4096))
715 pr_info("tree size %u", size);
716
717 BUG_ON(eytzinger1_prev(0, size) != eytzinger1_last(size));
718 BUG_ON(eytzinger1_next(0, size) != eytzinger1_first(size));
719
720 BUG_ON(eytzinger1_prev(eytzinger1_first(size), size) != 0);
721 BUG_ON(eytzinger1_next(eytzinger1_last(size), size) != 0);
722
723 inorder = 1;
724 eytzinger1_for_each(eytz, size) {
725 BUG_ON(__inorder_to_eytzinger1(inorder, size, extra) != eytz);
726 BUG_ON(__eytzinger1_to_inorder(eytz, size, extra) != inorder);
727 BUG_ON(eytz != eytzinger1_last(size) &&
728 eytzinger1_prev(eytzinger1_next(eytz, size), size) != eytz);
729
730 inorder++;
731 }
732 }
733 }
734
735 void eytzinger0_test(void)
736 {
737
738 unsigned inorder, eytz, size;
739
740 pr_info("0 based eytzinger test:");
741
742 for (size = 1;
743 size < 65536;
744 size++) {
745 unsigned extra = eytzinger0_extra(size);
746
747 if (!(size % 4096))
748 pr_info("tree size %u", size);
749
750 BUG_ON(eytzinger0_prev(-1, size) != eytzinger0_last(size));
751 BUG_ON(eytzinger0_next(-1, size) != eytzinger0_first(size));
752
753 BUG_ON(eytzinger0_prev(eytzinger0_first(size), size) != -1);
754 BUG_ON(eytzinger0_next(eytzinger0_last(size), size) != -1);
755
756 inorder = 0;
757 eytzinger0_for_each(eytz, size) {
758 BUG_ON(__inorder_to_eytzinger0(inorder, size, extra) != eytz);
759 BUG_ON(__eytzinger0_to_inorder(eytz, size, extra) != inorder);
760 BUG_ON(eytz != eytzinger0_last(size) &&
761 eytzinger0_prev(eytzinger0_next(eytz, size), size) != eytz);
762
763 inorder++;
764 }
765 }
766 }
767
768 static inline int cmp_u16(const void *_l, const void *_r, size_t size)
769 {
770 const u16 *l = _l, *r = _r;
771
772 return (*l > *r) - (*r - *l);
773 }
774
775 static void eytzinger0_find_test_val(u16 *test_array, unsigned nr, u16 search)
776 {
777 int i, c1 = -1, c2 = -1;
778 ssize_t r;
779
780 r = eytzinger0_find_le(test_array, nr,
781 sizeof(test_array[0]),
782 cmp_u16, &search);
783 if (r >= 0)
784 c1 = test_array[r];
785
786 for (i = 0; i < nr; i++)
787 if (test_array[i] <= search && test_array[i] > c2)
788 c2 = test_array[i];
789
790 if (c1 != c2) {
791 eytzinger0_for_each(i, nr)
792 pr_info("[%3u] = %12u", i, test_array[i]);
793 pr_info("find_le(%2u) -> [%2zi] = %2i should be %2i",
794 i, r, c1, c2);
795 }
796 }
797
798 void eytzinger0_find_test(void)
799 {
800 unsigned i, nr, allocated = 1 << 12;
801 u16 *test_array = kmalloc_array(allocated, sizeof(test_array[0]), GFP_KERNEL);
802
803 for (nr = 1; nr < allocated; nr++) {
804 pr_info("testing %u elems", nr);
805
806 get_random_bytes(test_array, nr * sizeof(test_array[0]));
807 eytzinger0_sort(test_array, nr, sizeof(test_array[0]), cmp_u16, NULL);
808
809 /* verify array is sorted correctly: */
810 eytzinger0_for_each(i, nr)
811 BUG_ON(i != eytzinger0_last(nr) &&
812 test_array[i] > test_array[eytzinger0_next(i, nr)]);
813
814 for (i = 0; i < U16_MAX; i += 1 << 12)
815 eytzinger0_find_test_val(test_array, nr, i);
816
817 for (i = 0; i < nr; i++) {
818 eytzinger0_find_test_val(test_array, nr, test_array[i] - 1);
819 eytzinger0_find_test_val(test_array, nr, test_array[i]);
820 eytzinger0_find_test_val(test_array, nr, test_array[i] + 1);
821 }
822 }
823
824 kfree(test_array);
825 }
826 #endif
827
828 /*
829 * Accumulate percpu counters onto one cpu's copy - only valid when access
830 * against any percpu counter is guarded against
831 */
832 u64 *bch2_acc_percpu_u64s(u64 __percpu *p, unsigned nr)
833 {
834 u64 *ret;
835 int cpu;
836
837 /* access to pcpu vars has to be blocked by other locking */
838 preempt_disable();
839 ret = this_cpu_ptr(p);
840 preempt_enable();
841
842 for_each_possible_cpu(cpu) {
843 u64 *i = per_cpu_ptr(p, cpu);
844
845 if (i != ret) {
846 acc_u64s(ret, i, nr);
847 memset(i, 0, nr * sizeof(u64));
848 }
849 }
850
851 return ret;
852 }
853
854 void bch2_darray_str_exit(darray_str *d)
855 {
856 darray_for_each(*d, i)
857 kfree(*i);
858 darray_exit(d);
859 }
860
861 int bch2_split_devs(const char *_dev_name, darray_str *ret)
862 {
863 darray_init(ret);
864
865 char *dev_name, *s, *orig;
866
867 dev_name = orig = kstrdup(_dev_name, GFP_KERNEL);
868 if (!dev_name)
869 return -ENOMEM;
870
871 while ((s = strsep(&dev_name, ":"))) {
872 char *p = kstrdup(s, GFP_KERNEL);
873 if (!p)
874 goto err;
875
876 if (darray_push(ret, p)) {
877 kfree(p);
878 goto err;
879 }
880 }
881
882 kfree(orig);
883 return 0;
884 err:
885 bch2_darray_str_exit(ret);
886 kfree(orig);
887 return -ENOMEM;
888 }
889
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