Drop the heap-related macros from bcachefs and replacing them with the generic min_heap implementation from include/linux. By doing so, code readability is improved by using functions instead of macros. Moreover, the min_heap implementation in include/linux adopts a bottom-up variation compared to the textbook version currently used in bcachefs. This bottom-up variation allows for approximately 50% reduction in the number of comparison operations during heap siftdown, without changing the number of swaps, thus making it more efficient. Link: https://lkml.kernel.org/ioyfizrzq7w7mjrqcadtzsfgpuntowtjdw5pgn4qhvsdp4mqqg@nrlek5vmisbu Signed-off-by: Kuan-Wei Chiu <visitorckw@xxxxxxxxx> --- Changes in v2: - Add attribute __always_unused to the compare and swap functions that do not use the args parameter. - Rename min_heapify() to min_heap_sift_down(). - Refine the commit message. fs/bcachefs/clock.c | 53 +++++++++++----- fs/bcachefs/clock_types.h | 2 +- fs/bcachefs/ec.c | 100 +++++++++++++++++++----------- fs/bcachefs/ec_types.h | 2 +- fs/bcachefs/util.h | 127 +++----------------------------------- 5 files changed, 110 insertions(+), 174 deletions(-) diff --git a/fs/bcachefs/clock.c b/fs/bcachefs/clock.c index 363644451106..e898f4693bd0 100644 --- a/fs/bcachefs/clock.c +++ b/fs/bcachefs/clock.c @@ -6,16 +6,29 @@ #include <linux/kthread.h> #include <linux/preempt.h> -static inline long io_timer_cmp(io_timer_heap *h, - struct io_timer *l, - struct io_timer *r) +static inline bool io_timer_cmp(const void *l, const void *r, void __always_unused *args) { - return l->expire - r->expire; + struct io_timer *_l = (struct io_timer *)l; + struct io_timer *_r = (struct io_timer *)r; + + return _l->expire >= _r->expire; +} + +static inline void io_timer_swp(void *l, void *r, void __always_unused *args) +{ + struct io_timer *_l = (struct io_timer *)l; + struct io_timer *_r = (struct io_timer *)r; + + swap(*_l, *_r); } void bch2_io_timer_add(struct io_clock *clock, struct io_timer *timer) { size_t i; + const struct min_heap_callbacks callbacks = { + .less = io_timer_cmp, + .swp = io_timer_swp, + }; spin_lock(&clock->timer_lock); @@ -26,11 +39,11 @@ void bch2_io_timer_add(struct io_clock *clock, struct io_timer *timer) return; } - for (i = 0; i < clock->timers.used; i++) - if (clock->timers.data[i] == timer) + for (i = 0; i < clock->timers.heap.nr; i++) + if (min_heap_peek(&clock->timers)[i] == timer) goto out; - BUG_ON(!heap_add(&clock->timers, timer, io_timer_cmp, NULL)); + BUG_ON(!min_heap_push(&clock->timers, &timer, &callbacks, NULL)); out: spin_unlock(&clock->timer_lock); } @@ -38,12 +51,16 @@ void bch2_io_timer_add(struct io_clock *clock, struct io_timer *timer) void bch2_io_timer_del(struct io_clock *clock, struct io_timer *timer) { size_t i; + const struct min_heap_callbacks callbacks = { + .less = io_timer_cmp, + .swp = io_timer_swp, + }; spin_lock(&clock->timer_lock); - for (i = 0; i < clock->timers.used; i++) - if (clock->timers.data[i] == timer) { - heap_del(&clock->timers, i, io_timer_cmp, NULL); + for (i = 0; i < clock->timers.heap.nr; i++) + if (min_heap_peek(&clock->timers)[i] == timer) { + min_heap_pop(&clock->timers, &callbacks, NULL); break; } @@ -131,12 +148,16 @@ static struct io_timer *get_expired_timer(struct io_clock *clock, unsigned long now) { struct io_timer *ret = NULL; + const struct min_heap_callbacks callbacks = { + .less = io_timer_cmp, + .swp = io_timer_swp, + }; spin_lock(&clock->timer_lock); - if (clock->timers.used && - time_after_eq(now, clock->timers.data[0]->expire)) - heap_pop(&clock->timers, ret, io_timer_cmp, NULL); + if (clock->timers.heap.nr && + time_after_eq(now, min_heap_peek(&clock->timers)[0]->expire)) + min_heap_pop(&clock->timers, &callbacks, NULL); spin_unlock(&clock->timer_lock); @@ -161,10 +182,10 @@ void bch2_io_timers_to_text(struct printbuf *out, struct io_clock *clock) spin_lock(&clock->timer_lock); now = atomic64_read(&clock->now); - for (i = 0; i < clock->timers.used; i++) + for (i = 0; i < clock->timers.heap.nr; i++) prt_printf(out, "%ps:\t%li\n", - clock->timers.data[i]->fn, - clock->timers.data[i]->expire - now); + min_heap_peek(&clock->timers)[i]->fn, + min_heap_peek(&clock->timers)[i]->expire - now); spin_unlock(&clock->timer_lock); --out->atomic; } diff --git a/fs/bcachefs/clock_types.h b/fs/bcachefs/clock_types.h index 5fae0012d808..b02b24b9d74f 100644 --- a/fs/bcachefs/clock_types.h +++ b/fs/bcachefs/clock_types.h @@ -23,7 +23,7 @@ struct io_timer { /* Amount to buffer up on a percpu counter */ #define IO_CLOCK_PCPU_SECTORS 128 -typedef HEAP(struct io_timer *) io_timer_heap; +typedef MIN_HEAP(struct io_timer *, io_timer_heap) io_timer_heap; struct io_clock { atomic64_t now; diff --git a/fs/bcachefs/ec.c b/fs/bcachefs/ec.c index 082075244e16..68c5e9e928a7 100644 --- a/fs/bcachefs/ec.c +++ b/fs/bcachefs/ec.c @@ -860,14 +860,15 @@ static int __ec_stripe_mem_alloc(struct bch_fs *c, size_t idx, gfp_t gfp) { ec_stripes_heap n, *h = &c->ec_stripes_heap; - if (idx >= h->size) { + if (idx >= h->heap.size) { if (!init_heap(&n, max(1024UL, roundup_pow_of_two(idx + 1)), gfp)) return -BCH_ERR_ENOMEM_ec_stripe_mem_alloc; mutex_lock(&c->ec_stripes_heap_lock); - if (n.size > h->size) { - memcpy(n.data, h->data, h->used * sizeof(h->data[0])); - n.used = h->used; + if (n.heap.size > h->heap.size) { + memcpy(min_heap_peek(&n), min_heap_peek(h), + h->heap.nr * sizeof(*min_heap_peek(h))); + n.heap.nr = h->heap.nr; swap(*h, n); } mutex_unlock(&c->ec_stripes_heap_lock); @@ -958,20 +959,21 @@ static u64 stripe_idx_to_delete(struct bch_fs *c) lockdep_assert_held(&c->ec_stripes_heap_lock); - if (h->used && - h->data[0].blocks_nonempty == 0 && - !bch2_stripe_is_open(c, h->data[0].idx)) - return h->data[0].idx; + if (h->heap.nr && + min_heap_peek(h)->blocks_nonempty == 0 && + !bch2_stripe_is_open(c, min_heap_peek(h)->idx)) + return min_heap_peek(h)->idx; return 0; } -static inline int ec_stripes_heap_cmp(ec_stripes_heap *h, - struct ec_stripe_heap_entry l, - struct ec_stripe_heap_entry r) +static inline bool ec_stripes_heap_cmp(const void *l, const void *r, void __always_unused *args) { - return ((l.blocks_nonempty > r.blocks_nonempty) - - (l.blocks_nonempty < r.blocks_nonempty)); + struct ec_stripe_heap_entry *_l = (struct ec_stripe_heap_entry *)l; + struct ec_stripe_heap_entry *_r = (struct ec_stripe_heap_entry *)r; + + return ((_l->blocks_nonempty > _r->blocks_nonempty) >= + (_l->blocks_nonempty < _r->blocks_nonempty)); } static inline void ec_stripes_heap_set_backpointer(ec_stripes_heap *h, @@ -979,7 +981,21 @@ static inline void ec_stripes_heap_set_backpointer(ec_stripes_heap *h, { struct bch_fs *c = container_of(h, struct bch_fs, ec_stripes_heap); - genradix_ptr(&c->stripes, h->data[i].idx)->heap_idx = i; + genradix_ptr(&c->stripes, min_heap_peek(h)[i].idx)->heap_idx = i; +} + +static inline void ec_stripes_heap_swap(void *l, void *r, void *h) +{ + struct ec_stripe_heap_entry *_l = (struct ec_stripe_heap_entry *)l; + struct ec_stripe_heap_entry *_r = (struct ec_stripe_heap_entry *)r; + ec_stripes_heap *_h = (ec_stripes_heap *)h; + size_t i = _l - min_heap_peek(_h); + size_t j = _r - min_heap_peek(_h); + + ec_stripes_heap_set_backpointer(_h, i); + ec_stripes_heap_set_backpointer(_h, j); + + swap(*_l, *_r); } static void heap_verify_backpointer(struct bch_fs *c, size_t idx) @@ -987,34 +1003,43 @@ static void heap_verify_backpointer(struct bch_fs *c, size_t idx) ec_stripes_heap *h = &c->ec_stripes_heap; struct stripe *m = genradix_ptr(&c->stripes, idx); - BUG_ON(m->heap_idx >= h->used); - BUG_ON(h->data[m->heap_idx].idx != idx); + BUG_ON(m->heap_idx >= h->heap.nr); + BUG_ON(min_heap_peek(h)[m->heap_idx].idx != idx); } void bch2_stripes_heap_del(struct bch_fs *c, struct stripe *m, size_t idx) { + const struct min_heap_callbacks callbacks = { + .less = ec_stripes_heap_cmp, + .swp = ec_stripes_heap_swap, + }; + mutex_lock(&c->ec_stripes_heap_lock); heap_verify_backpointer(c, idx); - heap_del(&c->ec_stripes_heap, m->heap_idx, - ec_stripes_heap_cmp, - ec_stripes_heap_set_backpointer); + min_heap_del(&c->ec_stripes_heap, m->heap_idx, &callbacks, &c->ec_stripes_heap); mutex_unlock(&c->ec_stripes_heap_lock); } void bch2_stripes_heap_insert(struct bch_fs *c, struct stripe *m, size_t idx) { + const struct min_heap_callbacks callbacks = { + .less = ec_stripes_heap_cmp, + .swp = ec_stripes_heap_swap, + }; + mutex_lock(&c->ec_stripes_heap_lock); - BUG_ON(heap_full(&c->ec_stripes_heap)); + BUG_ON(min_heap_full(&c->ec_stripes_heap)); - heap_add(&c->ec_stripes_heap, ((struct ec_stripe_heap_entry) { + genradix_ptr(&c->stripes, idx)->heap_idx = c->ec_stripes_heap.heap.nr; + min_heap_push(&c->ec_stripes_heap, &((struct ec_stripe_heap_entry) { .idx = idx, .blocks_nonempty = m->blocks_nonempty, }), - ec_stripes_heap_cmp, - ec_stripes_heap_set_backpointer); + &callbacks, + &c->ec_stripes_heap); heap_verify_backpointer(c, idx); mutex_unlock(&c->ec_stripes_heap_lock); @@ -1026,17 +1051,20 @@ void bch2_stripes_heap_update(struct bch_fs *c, ec_stripes_heap *h = &c->ec_stripes_heap; bool do_deletes; size_t i; + const struct min_heap_callbacks callbacks = { + .less = ec_stripes_heap_cmp, + .swp = ec_stripes_heap_swap, + }; mutex_lock(&c->ec_stripes_heap_lock); heap_verify_backpointer(c, idx); - h->data[m->heap_idx].blocks_nonempty = m->blocks_nonempty; + min_heap_peek(h)[m->heap_idx].blocks_nonempty = m->blocks_nonempty; i = m->heap_idx; - heap_sift_up(h, i, ec_stripes_heap_cmp, - ec_stripes_heap_set_backpointer); - heap_sift_down(h, i, ec_stripes_heap_cmp, - ec_stripes_heap_set_backpointer); + + min_heap_sift_up(h, i, &callbacks, &c->ec_stripes_heap); + min_heap_sift_down(h, i, &callbacks, &c->ec_stripes_heap); heap_verify_backpointer(c, idx); @@ -1828,12 +1856,12 @@ static s64 get_existing_stripe(struct bch_fs *c, return -1; mutex_lock(&c->ec_stripes_heap_lock); - for (heap_idx = 0; heap_idx < h->used; heap_idx++) { + for (heap_idx = 0; heap_idx < h->heap.nr; heap_idx++) { /* No blocks worth reusing, stripe will just be deleted: */ - if (!h->data[heap_idx].blocks_nonempty) + if (!min_heap_peek(h)[heap_idx].blocks_nonempty) continue; - stripe_idx = h->data[heap_idx].idx; + stripe_idx = min_heap_peek(h)[heap_idx].idx; m = genradix_ptr(&c->stripes, stripe_idx); @@ -2159,14 +2187,14 @@ void bch2_stripes_heap_to_text(struct printbuf *out, struct bch_fs *c) size_t i; mutex_lock(&c->ec_stripes_heap_lock); - for (i = 0; i < min_t(size_t, h->used, 50); i++) { - m = genradix_ptr(&c->stripes, h->data[i].idx); + for (i = 0; i < min_t(size_t, h->heap.nr, 50); i++) { + m = genradix_ptr(&c->stripes, min_heap_peek(h)[i].idx); - prt_printf(out, "%zu %u/%u+%u", h->data[i].idx, - h->data[i].blocks_nonempty, + prt_printf(out, "%zu %u/%u+%u", min_heap_peek(h)[i].idx, + min_heap_peek(h)[i].blocks_nonempty, m->nr_blocks - m->nr_redundant, m->nr_redundant); - if (bch2_stripe_is_open(c, h->data[i].idx)) + if (bch2_stripe_is_open(c, min_heap_peek(h)[i].idx)) prt_str(out, " open"); prt_newline(out); } diff --git a/fs/bcachefs/ec_types.h b/fs/bcachefs/ec_types.h index 976426da3a12..2ed67431a81c 100644 --- a/fs/bcachefs/ec_types.h +++ b/fs/bcachefs/ec_types.h @@ -36,6 +36,6 @@ struct ec_stripe_heap_entry { unsigned blocks_nonempty; }; -typedef HEAP(struct ec_stripe_heap_entry) ec_stripes_heap; +typedef MIN_HEAP(struct ec_stripe_heap_entry, ec_stripes_heap) ec_stripes_heap; #endif /* _BCACHEFS_EC_TYPES_H */ diff --git a/fs/bcachefs/util.h b/fs/bcachefs/util.h index 175aee3074c7..e0c86ad04bf3 100644 --- a/fs/bcachefs/util.h +++ b/fs/bcachefs/util.h @@ -8,6 +8,7 @@ #include <linux/errno.h> #include <linux/freezer.h> #include <linux/kernel.h> +#include <linux/min_heap.h> #include <linux/sched/clock.h> #include <linux/llist.h> #include <linux/log2.h> @@ -54,134 +55,20 @@ static inline size_t buf_pages(void *p, size_t len) PAGE_SIZE); } -#define HEAP(type) \ -struct { \ - size_t size, used; \ - type *data; \ -} - -#define DECLARE_HEAP(type, name) HEAP(type) name - #define init_heap(heap, _size, gfp) \ ({ \ - (heap)->used = 0; \ - (heap)->size = (_size); \ - (heap)->data = kvmalloc((heap)->size * sizeof((heap)->data[0]),\ - (gfp)); \ -}) - -#define free_heap(heap) \ -do { \ - kvfree((heap)->data); \ - (heap)->data = NULL; \ -} while (0) - -#define heap_set_backpointer(h, i, _fn) \ -do { \ - void (*fn)(typeof(h), size_t) = _fn; \ - if (fn) \ - fn(h, i); \ -} while (0) - -#define heap_swap(h, i, j, set_backpointer) \ -do { \ - swap((h)->data[i], (h)->data[j]); \ - heap_set_backpointer(h, i, set_backpointer); \ - heap_set_backpointer(h, j, set_backpointer); \ -} while (0) - -#define heap_peek(h) \ -({ \ - EBUG_ON(!(h)->used); \ - (h)->data[0]; \ -}) - -#define heap_full(h) ((h)->used == (h)->size) - -#define heap_sift_down(h, i, cmp, set_backpointer) \ -do { \ - size_t _c, _j = i; \ - \ - for (; _j * 2 + 1 < (h)->used; _j = _c) { \ - _c = _j * 2 + 1; \ - if (_c + 1 < (h)->used && \ - cmp(h, (h)->data[_c], (h)->data[_c + 1]) >= 0) \ - _c++; \ - \ - if (cmp(h, (h)->data[_c], (h)->data[_j]) >= 0) \ - break; \ - heap_swap(h, _c, _j, set_backpointer); \ - } \ -} while (0) - -#define heap_sift_up(h, i, cmp, set_backpointer) \ -do { \ - while (i) { \ - size_t p = (i - 1) / 2; \ - if (cmp(h, (h)->data[i], (h)->data[p]) >= 0) \ - break; \ - heap_swap(h, i, p, set_backpointer); \ - i = p; \ - } \ -} while (0) - -#define __heap_add(h, d, cmp, set_backpointer) \ -({ \ - size_t _i = (h)->used++; \ - (h)->data[_i] = d; \ - heap_set_backpointer(h, _i, set_backpointer); \ - \ - heap_sift_up(h, _i, cmp, set_backpointer); \ - _i; \ -}) - -#define heap_add(h, d, cmp, set_backpointer) \ -({ \ - bool _r = !heap_full(h); \ - if (_r) \ - __heap_add(h, d, cmp, set_backpointer); \ - _r; \ + void *data = kvmalloc(_size * sizeof(*min_heap_peek(heap)), (gfp));\ + min_heap_init(heap, data, _size); \ + min_heap_peek(heap); \ }) -#define heap_add_or_replace(h, new, cmp, set_backpointer) \ -do { \ - if (!heap_add(h, new, cmp, set_backpointer) && \ - cmp(h, new, heap_peek(h)) >= 0) { \ - (h)->data[0] = new; \ - heap_set_backpointer(h, 0, set_backpointer); \ - heap_sift_down(h, 0, cmp, set_backpointer); \ - } \ -} while (0) -#define heap_del(h, i, cmp, set_backpointer) \ +#define free_heap(_heap) \ do { \ - size_t _i = (i); \ - \ - BUG_ON(_i >= (h)->used); \ - (h)->used--; \ - if ((_i) < (h)->used) { \ - heap_swap(h, _i, (h)->used, set_backpointer); \ - heap_sift_up(h, _i, cmp, set_backpointer); \ - heap_sift_down(h, _i, cmp, set_backpointer); \ - } \ + kvfree((_heap)->heap.data); \ + (_heap)->heap.data = NULL; \ } while (0) -#define heap_pop(h, d, cmp, set_backpointer) \ -({ \ - bool _r = (h)->used; \ - if (_r) { \ - (d) = (h)->data[0]; \ - heap_del(h, 0, cmp, set_backpointer); \ - } \ - _r; \ -}) - -#define heap_resort(heap, cmp, set_backpointer) \ -do { \ - ssize_t _i; \ - for (_i = (ssize_t) (heap)->used / 2 - 1; _i >= 0; --_i) \ - heap_sift_down(heap, _i, cmp, set_backpointer); \ -} while (0) #define ANYSINT_MAX(t) \ ((((t) 1 << (sizeof(t) * 8 - 2)) - (t) 1) * (t) 2 + (t) 1) -- 2.34.1
