Re: [PATCH v3 16/17] bcache: Remove heap-related macros and switch to generic min_heap

Coly Li
2024-04-09T08:11:31Z

On Sun, Apr 07, 2024 at 12:47:26AM +0800, Kuan-Wei Chiu wrote:
> Drop the heap-related macros from bcache 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 bcache.
> 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@gmail.com>
> Reviewed-by: Ian Rogers <irogers@google.com>

For the bcache replacement part,

Acked-by: Coly Li <colyli@suse.de>

Thanks.

Coly Li
> ---
> Changes in v3:
> - Correct bugs where the parameter types in some compare functions
> should have been 'type **', but were mistakenly written as 'type *'.
>
> drivers/md/bcache/alloc.c | 64 +++++++++++++++++++-------
> drivers/md/bcache/bcache.h | 2 +-
> drivers/md/bcache/bset.c | 84 ++++++++++++++++++++++++-----------
> drivers/md/bcache/bset.h | 14 +++---
> drivers/md/bcache/btree.c | 17 ++++++-
> drivers/md/bcache/extents.c | 53 ++++++++++++++--------
> drivers/md/bcache/movinggc.c | 41 ++++++++++++-----
> drivers/md/bcache/sysfs.c | 2 +
> drivers/md/bcache/util.h | 67 +---------------------------
> drivers/md/bcache/writeback.c | 3 ++
> 10 files changed, 202 insertions(+), 145 deletions(-)
>
> diff --git a/drivers/md/bcache/alloc.c b/drivers/md/bcache/alloc.c
> index ce13c272c387..8cfa15ea32b4 100644
> --- a/drivers/md/bcache/alloc.c
> +++ b/drivers/md/bcache/alloc.c
> @@ -166,40 +166,68 @@ static void bch_invalidate_one_bucket(struct cache *ca, struct bucket *b)
> * prio is worth 1/8th of what INITIAL_PRIO is worth.
> */
>
> -#define bucket_prio(b) \
> -({ \
> - unsigned int min_prio = (INITIAL_PRIO - ca->set->min_prio) / 8; \
> - \
> - (b->prio - ca->set->min_prio + min_prio) * GC_SECTORS_USED(b); \
> -})
> +static inline unsigned int new_bucket_prio(struct cache *ca, struct bucket *b)
> +{
> + unsigned int min_prio = (INITIAL_PRIO - ca->set->min_prio) / 8;
> +
> + return (b->prio - ca->set->min_prio + min_prio) * GC_SECTORS_USED(b);
> +}
> +
> +static inline bool new_bucket_max_cmp(const void *l, const void *r, void *args)
> +{
> + struct bucket **lhs = (struct bucket **)l;
> + struct bucket **rhs = (struct bucket **)r;
> + struct cache *ca = args;
> +
> + return new_bucket_prio(ca, *lhs) > new_bucket_prio(ca, *rhs);
> +}
>
> -#define bucket_max_cmp(l, r) (bucket_prio(l) < bucket_prio(r))
> -#define bucket_min_cmp(l, r) (bucket_prio(l) > bucket_prio(r))
> +static inline bool new_bucket_min_cmp(const void *l, const void *r, void *args)
> +{
> + struct bucket **lhs = (struct bucket **)l;
> + struct bucket **rhs = (struct bucket **)r;
> + struct cache *ca = args;
> +
> + return new_bucket_prio(ca, *lhs) < new_bucket_prio(ca, *rhs);
> +}
> +
> +static inline void new_bucket_swap(void *l, void *r, void __always_unused *args)
> +{
> + struct bucket **lhs = l, **rhs = r;
> +
> + swap(*lhs, *rhs);
> +}
>
> static void invalidate_buckets_lru(struct cache *ca)
> {
> struct bucket *b;
> - ssize_t i;
> + const struct min_heap_callbacks bucket_max_cmp_callback = {
> + .less = new_bucket_max_cmp,
> + .swp = new_bucket_swap,
> + };
> + const struct min_heap_callbacks bucket_min_cmp_callback = {
> + .less = new_bucket_min_cmp,
> + .swp = new_bucket_swap,
> + };
>
> - ca->heap.used = 0;
> + ca->heap.nr = 0;
>
> for_each_bucket(b, ca) {
> if (!bch_can_invalidate_bucket(ca, b))
> continue;
>
> - if (!heap_full(&ca->heap))
> - heap_add(&ca->heap, b, bucket_max_cmp);
> - else if (bucket_max_cmp(b, heap_peek(&ca->heap))) {
> + if (!min_heap_full(&ca->heap))
> + min_heap_push(&ca->heap, &b, &bucket_max_cmp_callback, ca);
> + else if (!new_bucket_max_cmp(&b, min_heap_peek(&ca->heap), ca)) {
> ca->heap.data[0] = b;
> - heap_sift(&ca->heap, 0, bucket_max_cmp);
> + min_heap_sift_down(&ca->heap, 0, &bucket_max_cmp_callback, ca);
> }
> }
>
> - for (i = ca->heap.used / 2 - 1; i >= 0; --i)
> - heap_sift(&ca->heap, i, bucket_min_cmp);
> + min_heapify_all(&ca->heap, &bucket_min_cmp_callback, ca);
>
> while (!fifo_full(&ca->free_inc)) {
> - if (!heap_pop(&ca->heap, b, bucket_min_cmp)) {
> + if (!ca->heap.nr) {
> /*
> * We don't want to be calling invalidate_buckets()
> * multiple times when it can't do anything
> @@ -208,6 +236,8 @@ static void invalidate_buckets_lru(struct cache *ca)
> wake_up_gc(ca->set);
> return;
> }
> + b = min_heap_peek(&ca->heap)[0];
> + min_heap_pop(&ca->heap, &bucket_min_cmp_callback, ca);
>
> bch_invalidate_one_bucket(ca, b);
> }
> diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
> index 4e6afa89921f..575d1e3a5217 100644
> --- a/drivers/md/bcache/bcache.h
> +++ b/drivers/md/bcache/bcache.h
> @@ -457,7 +457,7 @@ struct cache {
> /* Allocation stuff: */
> struct bucket *buckets;
>
> - DECLARE_HEAP(struct bucket *, heap);
> + MIN_HEAP(struct bucket *, cache_heap) heap;
>
> /*
> * If nonzero, we know we aren't going to find any buckets to invalidate
> diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c
> index 2bba4d6aaaa2..bd97d8626887 100644
> --- a/drivers/md/bcache/bset.c
> +++ b/drivers/md/bcache/bset.c
> @@ -57,6 +57,8 @@ int __bch_count_data(struct btree_keys *b)
> struct btree_iter iter;
> struct bkey *k;
>
> + min_heap_init(&iter.heap, NULL, MAX_BSETS);
> +
> if (b->ops->is_extents)
> for_each_key(b, k, &iter)
> ret += KEY_SIZE(k);
> @@ -70,6 +72,8 @@ void __bch_check_keys(struct btree_keys *b, const char *fmt, ...)
> struct btree_iter iter;
> const char *err;
>
> + min_heap_init(&iter.heap, NULL, MAX_BSETS);
> +
> for_each_key(b, k, &iter) {
> if (b->ops->is_extents) {
> err = "Keys out of order";
> @@ -110,9 +114,9 @@ void __bch_check_keys(struct btree_keys *b, const char *fmt, ...)
>
> static void bch_btree_iter_next_check(struct btree_iter *iter)
> {
> - struct bkey *k = iter->data->k, *next = bkey_next(k);
> + struct bkey *k = iter->heap.data->k, *next = bkey_next(k);
>
> - if (next < iter->data->end &&
> + if (next < iter->heap.data->end &&
> bkey_cmp(k, iter->b->ops->is_extents ?
> &START_KEY(next) : next) > 0) {
> bch_dump_bucket(iter->b);
> @@ -885,6 +889,8 @@ unsigned int bch_btree_insert_key(struct btree_keys *b, struct bkey *k,
>
> BUG_ON(b->ops->is_extents && !KEY_SIZE(k));
>
> + min_heap_init(&iter.heap, NULL, MAX_BSETS);
> +
> /*
> * If k has preceding key, preceding_key_p will be set to address
> * of k's preceding key; otherwise preceding_key_p will be set
> @@ -1077,27 +1083,42 @@ struct bkey *__bch_bset_search(struct btree_keys *b, struct bset_tree *t,
>
> /* Btree iterator */
>
> -typedef bool (btree_iter_cmp_fn)(struct btree_iter_set,
> - struct btree_iter_set);
> +typedef bool (new_btree_iter_cmp_fn)(const void *, const void *, void *);
> +
> +static inline bool new_btree_iter_cmp(const void *l, const void *r, void __always_unused *args)
> +{
> + const struct btree_iter_set *_l = l;
> + const struct btree_iter_set *_r = r;
> +
> + return bkey_cmp(_l->k, _r->k) <= 0;
> +}
>
> -static inline bool btree_iter_cmp(struct btree_iter_set l,
> - struct btree_iter_set r)
> +static inline void new_btree_iter_swap(void *iter1, void *iter2, void __always_unused *args)
> {
> - return bkey_cmp(l.k, r.k) > 0;
> + struct btree_iter_set *_iter1 = iter1;
> + struct btree_iter_set *_iter2 = iter2;
> +
> + swap(*_iter1, *_iter2);
> }
>
> static inline bool btree_iter_end(struct btree_iter *iter)
> {
> - return !iter->used;
> + return !iter->heap.nr;
> }
>
> void bch_btree_iter_push(struct btree_iter *iter, struct bkey *k,
> struct bkey *end)
> {
> + const struct min_heap_callbacks callbacks = {
> + .less = new_btree_iter_cmp,
> + .swp = new_btree_iter_swap,
> + };
> +
> if (k != end)
> - BUG_ON(!heap_add(iter,
> - ((struct btree_iter_set) { k, end }),
> - btree_iter_cmp));
> + BUG_ON(!min_heap_push(&iter->heap,
> + &((struct btree_iter_set) { k, end }),
> + &callbacks,
> + NULL));
> }
>
> static struct bkey *__bch_btree_iter_init(struct btree_keys *b,
> @@ -1107,8 +1128,8 @@ static struct bkey *__bch_btree_iter_init(struct btree_keys *b,
> {
> struct bkey *ret = NULL;
>
> - iter->size = ARRAY_SIZE(iter->data);
> - iter->used = 0;
> + iter->heap.size = ARRAY_SIZE(iter->heap.preallocated);
> + iter->heap.nr = 0;
>
> #ifdef CONFIG_BCACHE_DEBUG
> iter->b = b;
> @@ -1130,26 +1151,34 @@ struct bkey *bch_btree_iter_init(struct btree_keys *b,
> }
>
> static inline struct bkey *__bch_btree_iter_next(struct btree_iter *iter,
> - btree_iter_cmp_fn *cmp)
> + new_btree_iter_cmp_fn *cmp)
> {
> struct btree_iter_set b __maybe_unused;
> struct bkey *ret = NULL;
> + const struct min_heap_callbacks callbacks = {
> + .less = cmp,
> + .swp = new_btree_iter_swap,
> + };
>
> if (!btree_iter_end(iter)) {
> bch_btree_iter_next_check(iter);
>
> - ret = iter->data->k;
> - iter->data->k = bkey_next(iter->data->k);
> + ret = iter->heap.data->k;
> + iter->heap.data->k = bkey_next(iter->heap.data->k);
>
> - if (iter->data->k > iter->data->end) {
> + if (iter->heap.data->k > iter->heap.data->end) {
> WARN_ONCE(1, "bset was corrupt!\n");
> - iter->data->k = iter->data->end;
> + iter->heap.data->k = iter->heap.data->end;
> }
>
> - if (iter->data->k == iter->data->end)
> - heap_pop(iter, b, cmp);
> + if (iter->heap.data->k == iter->heap.data->end) {
> + if (iter->heap.nr) {
> + b = min_heap_peek(&iter->heap)[0];
> + min_heap_pop(&iter->heap, &callbacks, NULL);
> + }
> + }
> else
> - heap_sift(iter, 0, cmp);
> + min_heap_sift_down(&iter->heap, 0, &callbacks, NULL);
> }
>
> return ret;
> @@ -1157,7 +1186,7 @@ static inline struct bkey *__bch_btree_iter_next(struct btree_iter *iter,
>
> struct bkey *bch_btree_iter_next(struct btree_iter *iter)
> {
> - return __bch_btree_iter_next(iter, btree_iter_cmp);
> + return __bch_btree_iter_next(iter, new_btree_iter_cmp);
>
> }
>
> @@ -1195,16 +1224,18 @@ static void btree_mergesort(struct btree_keys *b, struct bset *out,
> struct btree_iter *iter,
> bool fixup, bool remove_stale)
> {
> - int i;
> struct bkey *k, *last = NULL;
> BKEY_PADDED(k) tmp;
> bool (*bad)(struct btree_keys *, const struct bkey *) = remove_stale
> ? bch_ptr_bad
> : bch_ptr_invalid;
> + const struct min_heap_callbacks callbacks = {
> + .less = b->ops->sort_cmp,
> + .swp = new_btree_iter_swap,
> + };
>
> /* Heapify the iterator, using our comparison function */
> - for (i = iter->used / 2 - 1; i >= 0; --i)
> - heap_sift(iter, i, b->ops->sort_cmp);
> + min_heapify_all(&iter->heap, &callbacks, NULL);
>
> while (!btree_iter_end(iter)) {
> if (b->ops->sort_fixup && fixup)
> @@ -1296,6 +1327,7 @@ void bch_btree_sort_partial(struct btree_keys *b, unsigned int start,
> struct btree_iter iter;
> int oldsize = bch_count_data(b);
>
> + min_heap_init(&iter.heap, NULL, MAX_BSETS);
> __bch_btree_iter_init(b, &iter, NULL, &b->set[start]);
>
> if (start) {
> @@ -1325,6 +1357,8 @@ void bch_btree_sort_into(struct btree_keys *b, struct btree_keys *new,
> uint64_t start_time = local_clock();
> struct btree_iter iter;
>
> + min_heap_init(&iter.heap, NULL, MAX_BSETS);
> +
> bch_btree_iter_init(b, &iter, NULL);
>
> btree_mergesort(b, new->set->data, &iter, false, true);
> diff --git a/drivers/md/bcache/bset.h b/drivers/md/bcache/bset.h
> index d795c84246b0..f79441acd4c1 100644
> --- a/drivers/md/bcache/bset.h
> +++ b/drivers/md/bcache/bset.h
> @@ -187,8 +187,9 @@ struct bset_tree {
> };
>
> struct btree_keys_ops {
> - bool (*sort_cmp)(struct btree_iter_set l,
> - struct btree_iter_set r);
> + bool (*sort_cmp)(const void *l,
> + const void *r,
> + void *args);
> struct bkey *(*sort_fixup)(struct btree_iter *iter,
> struct bkey *tmp);
> bool (*insert_fixup)(struct btree_keys *b,
> @@ -312,16 +313,17 @@ enum {
> BTREE_INSERT_STATUS_FRONT_MERGE,
> };
>
> +struct btree_iter_set {
> + struct bkey *k, *end;
> +};
> +
> /* Btree key iteration */
>
> struct btree_iter {
> - size_t size, used;
> #ifdef CONFIG_BCACHE_DEBUG
> struct btree_keys *b;
> #endif
> - struct btree_iter_set {
> - struct bkey *k, *end;
> - } data[MAX_BSETS];
> + MIN_HEAP_PREALLOCATED(struct btree_iter_set, btree_iter_heap, MAX_BSETS) heap;
> };
>
> typedef bool (*ptr_filter_fn)(struct btree_keys *b, const struct bkey *k);
> diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
> index 196cdacce38f..a2bb86d52ad4 100644
> --- a/drivers/md/bcache/btree.c
> +++ b/drivers/md/bcache/btree.c
> @@ -157,8 +157,8 @@ void bch_btree_node_read_done(struct btree *b)
> * See the comment arount cache_set->fill_iter.
> */
> iter = mempool_alloc(&b->c->fill_iter, GFP_NOIO);
> - iter->size = b->c->cache->sb.bucket_size / b->c->cache->sb.block_size;
> - iter->used = 0;
> + iter->heap.size = b->c->cache->sb.bucket_size / b->c->cache->sb.block_size;
> + iter->heap.nr = 0;
>
> #ifdef CONFIG_BCACHE_DEBUG
> iter->b = &b->keys;
> @@ -1312,6 +1312,8 @@ static bool btree_gc_mark_node(struct btree *b, struct gc_stat *gc)
> struct btree_iter iter;
> struct bset_tree *t;
>
> + min_heap_init(&iter.heap, NULL, MAX_BSETS);
> +
> gc->nodes++;
>
> for_each_key_filter(&b->keys, k, &iter, bch_ptr_invalid) {
> @@ -1573,6 +1575,8 @@ static unsigned int btree_gc_count_keys(struct btree *b)
> struct btree_iter iter;
> unsigned int ret = 0;
>
> + min_heap_init(&iter.heap, NULL, MAX_BSETS);
> +
> for_each_key_filter(&b->keys, k, &iter, bch_ptr_bad)
> ret += bkey_u64s(k);
>
> @@ -1615,6 +1619,7 @@ static int btree_gc_recurse(struct btree *b, struct btree_op *op,
> struct gc_merge_info r[GC_MERGE_NODES];
> struct gc_merge_info *i, *last = r + ARRAY_SIZE(r) - 1;
>
> + min_heap_init(&iter.heap, NULL, MAX_BSETS);
> bch_btree_iter_init(&b->keys, &iter, &b->c->gc_done);
>
> for (i = r; i < r + ARRAY_SIZE(r); i++)
> @@ -1913,6 +1918,8 @@ static int bch_btree_check_recurse(struct btree *b, struct btree_op *op)
> struct bkey *k, *p = NULL;
> struct btree_iter iter;
>
> + min_heap_init(&iter.heap, NULL, MAX_BSETS);
> +
> for_each_key_filter(&b->keys, k, &iter, bch_ptr_invalid)
> bch_initial_mark_key(b->c, b->level, k);
>
> @@ -1958,6 +1965,8 @@ static int bch_btree_check_thread(void *arg)
> cur_idx = prev_idx = 0;
> ret = 0;
>
> + min_heap_init(&iter.heap, NULL, MAX_BSETS);
> +
> /* root node keys are checked before thread created */
> bch_btree_iter_init(&c->root->keys, &iter, NULL);
> k = bch_btree_iter_next_filter(&iter, &c->root->keys, bch_ptr_bad);
> @@ -2054,6 +2063,8 @@ int bch_btree_check(struct cache_set *c)
> struct btree_iter iter;
> struct btree_check_state check_state;
>
> + min_heap_init(&iter.heap, NULL, MAX_BSETS);
> +
> /* check and mark root node keys */
> for_each_key_filter(&c->root->keys, k, &iter, bch_ptr_invalid)
> bch_initial_mark_key(c, c->root->level, k);
> @@ -2549,6 +2560,7 @@ static int bch_btree_map_nodes_recurse(struct btree *b, struct btree_op *op,
> struct bkey *k;
> struct btree_iter iter;
>
> + min_heap_init(&iter.heap, NULL, MAX_BSETS);
> bch_btree_iter_init(&b->keys, &iter, from);
>
> while ((k = bch_btree_iter_next_filter(&iter, &b->keys,
> @@ -2582,6 +2594,7 @@ int bch_btree_map_keys_recurse(struct btree *b, struct btree_op *op,
> struct bkey *k;
> struct btree_iter iter;
>
> + min_heap_init(&iter.heap, NULL, MAX_BSETS);
> bch_btree_iter_init(&b->keys, &iter, from);
>
> while ((k = bch_btree_iter_next_filter(&iter, &b->keys, bch_ptr_bad))) {
> diff --git a/drivers/md/bcache/extents.c b/drivers/md/bcache/extents.c
> index d626ffcbecb9..a7221e5dbe81 100644
> --- a/drivers/md/bcache/extents.c
> +++ b/drivers/md/bcache/extents.c
> @@ -33,15 +33,16 @@ static void sort_key_next(struct btree_iter *iter,
> i->k = bkey_next(i->k);
>
> if (i->k == i->end)
> - *i = iter->data[--iter->used];
> + *i = iter->heap.data[--iter->heap.nr];
> }
>
> -static bool bch_key_sort_cmp(struct btree_iter_set l,
> - struct btree_iter_set r)
> +static bool new_bch_key_sort_cmp(const void *l, const void *r, void *args)
> {
> - int64_t c = bkey_cmp(l.k, r.k);
> + struct btree_iter_set *_l = (struct btree_iter_set *)l;
> + struct btree_iter_set *_r = (struct btree_iter_set *)r;
> + int64_t c = bkey_cmp(_l->k, _r->k);
>
> - return c ? c > 0 : l.k < r.k;
> + return !(c ? c > 0 : _l->k < _r->k);
> }
>
> static bool __ptr_invalid(struct cache_set *c, const struct bkey *k)
> @@ -238,7 +239,7 @@ static bool bch_btree_ptr_insert_fixup(struct btree_keys *bk,
> }
>
> const struct btree_keys_ops bch_btree_keys_ops = {
> - .sort_cmp = bch_key_sort_cmp,
> + .sort_cmp = new_bch_key_sort_cmp,
> .insert_fixup = bch_btree_ptr_insert_fixup,
> .key_invalid = bch_btree_ptr_invalid,
> .key_bad = bch_btree_ptr_bad,
> @@ -255,22 +256,36 @@ const struct btree_keys_ops bch_btree_keys_ops = {
> * Necessary for btree_sort_fixup() - if there are multiple keys that compare
> * equal in different sets, we have to process them newest to oldest.
> */
> -static bool bch_extent_sort_cmp(struct btree_iter_set l,
> - struct btree_iter_set r)
> +
> +static bool new_bch_extent_sort_cmp(const void *l, const void *r, void __always_unused *args)
> +{
> + struct btree_iter_set *_l = (struct btree_iter_set *)l;
> + struct btree_iter_set *_r = (struct btree_iter_set *)r;
> + int64_t c = bkey_cmp(&START_KEY(_l->k), &START_KEY(_r->k));
> +
> + return !(c ? c > 0 : _l->k < _r->k);
> +}
> +
> +static inline void new_btree_iter_swap(void *iter1, void *iter2, void __always_unused *args)
> {
> - int64_t c = bkey_cmp(&START_KEY(l.k), &START_KEY(r.k));
> + struct btree_iter_set *_iter1 = iter1;
> + struct btree_iter_set *_iter2 = iter2;
>
> - return c ? c > 0 : l.k < r.k;
> + swap(*_iter1, *_iter2);
> }
>
> static struct bkey *bch_extent_sort_fixup(struct btree_iter *iter,
> struct bkey *tmp)
> {
> - while (iter->used > 1) {
> - struct btree_iter_set *top = iter->data, *i = top + 1;
> -
> - if (iter->used > 2 &&
> - bch_extent_sort_cmp(i[0], i[1]))
> + const struct min_heap_callbacks callbacks = {
> + .less = new_bch_extent_sort_cmp,
> + .swp = new_btree_iter_swap,
> + };
> + while (iter->heap.nr > 1) {
> + struct btree_iter_set *top = iter->heap.data, *i = top + 1;
> +
> + if (iter->heap.nr > 2 &&
> + !new_bch_extent_sort_cmp(&i[0], &i[1], NULL))
> i++;
>
> if (bkey_cmp(top->k, &START_KEY(i->k)) <= 0)
> @@ -278,7 +293,7 @@ static struct bkey *bch_extent_sort_fixup(struct btree_iter *iter,
>
> if (!KEY_SIZE(i->k)) {
> sort_key_next(iter, i);
> - heap_sift(iter, i - top, bch_extent_sort_cmp);
> + min_heap_sift_down(&iter->heap, i - top, &callbacks, NULL);
> continue;
> }
>
> @@ -288,7 +303,7 @@ static struct bkey *bch_extent_sort_fixup(struct btree_iter *iter,
> else
> bch_cut_front(top->k, i->k);
>
> - heap_sift(iter, i - top, bch_extent_sort_cmp);
> + min_heap_sift_down(&iter->heap, i - top, &callbacks, NULL);
> } else {
> /* can't happen because of comparison func */
> BUG_ON(!bkey_cmp(&START_KEY(top->k), &START_KEY(i->k)));
> @@ -298,7 +313,7 @@ static struct bkey *bch_extent_sort_fixup(struct btree_iter *iter,
>
> bch_cut_back(&START_KEY(i->k), tmp);
> bch_cut_front(i->k, top->k);
> - heap_sift(iter, 0, bch_extent_sort_cmp);
> + min_heap_sift_down(&iter->heap, 0, &callbacks, NULL);
>
> return tmp;
> } else {
> @@ -618,7 +633,7 @@ static bool bch_extent_merge(struct btree_keys *bk,
> }
>
> const struct btree_keys_ops bch_extent_keys_ops = {
> - .sort_cmp = bch_extent_sort_cmp,
> + .sort_cmp = new_bch_extent_sort_cmp,
> .sort_fixup = bch_extent_sort_fixup,
> .insert_fixup = bch_extent_insert_fixup,
> .key_invalid = bch_extent_invalid,
> diff --git a/drivers/md/bcache/movinggc.c b/drivers/md/bcache/movinggc.c
> index ebd500bdf0b2..7f482729c56d 100644
> --- a/drivers/md/bcache/movinggc.c
> +++ b/drivers/md/bcache/movinggc.c
> @@ -182,16 +182,27 @@ err: if (!IS_ERR_OR_NULL(w->private))
> closure_sync(&cl);
> }
>
> -static bool bucket_cmp(struct bucket *l, struct bucket *r)
> +static bool new_bucket_cmp(const void *l, const void *r, void __always_unused *args)
> {
> - return GC_SECTORS_USED(l) < GC_SECTORS_USED(r);
> + struct bucket **_l = (struct bucket **)l;
> + struct bucket **_r = (struct bucket **)r;
> +
> + return GC_SECTORS_USED(*_l) >= GC_SECTORS_USED(*_r);
> +}
> +
> +static void new_bucket_swap(void *l, void *r, void __always_unused *args)
> +{
> + struct bucket **_l = l;
> + struct bucket **_r = r;
> +
> + swap(*_l, *_r);
> }
>
> static unsigned int bucket_heap_top(struct cache *ca)
> {
> struct bucket *b;
>
> - return (b = heap_peek(&ca->heap)) ? GC_SECTORS_USED(b) : 0;
> + return (b = min_heap_peek(&ca->heap)[0]) ? GC_SECTORS_USED(b) : 0;
> }
>
> void bch_moving_gc(struct cache_set *c)
> @@ -199,6 +210,10 @@ void bch_moving_gc(struct cache_set *c)
> struct cache *ca = c->cache;
> struct bucket *b;
> unsigned long sectors_to_move, reserve_sectors;
> + const struct min_heap_callbacks callbacks = {
> + .less = new_bucket_cmp,
> + .swp = new_bucket_swap,
> + };
>
> if (!c->copy_gc_enabled)
> return;
> @@ -209,7 +224,7 @@ void bch_moving_gc(struct cache_set *c)
> reserve_sectors = ca->sb.bucket_size *
> fifo_used(&ca->free[RESERVE_MOVINGGC]);
>
> - ca->heap.used = 0;
> + ca->heap.nr = 0;
>
> for_each_bucket(b, ca) {
> if (GC_MARK(b) == GC_MARK_METADATA ||
> @@ -218,25 +233,31 @@ void bch_moving_gc(struct cache_set *c)
> atomic_read(&b->pin))
> continue;
>
> - if (!heap_full(&ca->heap)) {
> + if (!min_heap_full(&ca->heap)) {
> sectors_to_move += GC_SECTORS_USED(b);
> - heap_add(&ca->heap, b, bucket_cmp);
> - } else if (bucket_cmp(b, heap_peek(&ca->heap))) {
> + min_heap_push(&ca->heap, &b, &callbacks, NULL);
> + } else if (!new_bucket_cmp(&b, min_heap_peek(&ca->heap), ca)) {
> sectors_to_move -= bucket_heap_top(ca);
> sectors_to_move += GC_SECTORS_USED(b);
>
> ca->heap.data[0] = b;
> - heap_sift(&ca->heap, 0, bucket_cmp);
> + min_heap_sift_down(&ca->heap, 0, &callbacks, NULL);
> }
> }
>
> while (sectors_to_move > reserve_sectors) {
> - heap_pop(&ca->heap, b, bucket_cmp);
> + if (ca->heap.nr) {
> + b = min_heap_peek(&ca->heap)[0];
> + min_heap_pop(&ca->heap, &callbacks, NULL);
> + }
> sectors_to_move -= GC_SECTORS_USED(b);
> }
>
> - while (heap_pop(&ca->heap, b, bucket_cmp))
> + while (ca->heap.nr) {
> + b = min_heap_peek(&ca->heap)[0];
> + min_heap_pop(&ca->heap, &callbacks, NULL);
> SET_GC_MOVE(b, 1);
> + }
>
> mutex_unlock(&c->bucket_lock);
>
> diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
> index 6956beb55326..e8f696cb58c0 100644
> --- a/drivers/md/bcache/sysfs.c
> +++ b/drivers/md/bcache/sysfs.c
> @@ -662,6 +662,8 @@ static unsigned int bch_root_usage(struct cache_set *c)
> struct btree *b;
> struct btree_iter iter;
>
> + min_heap_init(&iter.heap, NULL, MAX_BSETS);
> +
> goto lock_root;
>
> do {
> diff --git a/drivers/md/bcache/util.h b/drivers/md/bcache/util.h
> index f61ab1bada6c..539454d8e2d0 100644
> --- a/drivers/md/bcache/util.h
> +++ b/drivers/md/bcache/util.h
> @@ -9,6 +9,7 @@
> #include <linux/kernel.h>
> #include <linux/sched/clock.h>
> #include <linux/llist.h>
> +#include <linux/min_heap.h>
> #include <linux/ratelimit.h>
> #include <linux/vmalloc.h>
> #include <linux/workqueue.h>
> @@ -30,16 +31,10 @@ struct closure;
>
> #endif
>
> -#define DECLARE_HEAP(type, name) \
> - struct { \
> - size_t size, used; \
> - type *data; \
> - } name
> -
> #define init_heap(heap, _size, gfp) \
> ({ \
> size_t _bytes; \
> - (heap)->used = 0; \
> + (heap)->nr = 0; \
> (heap)->size = (_size); \
> _bytes = (heap)->size * sizeof(*(heap)->data); \
> (heap)->data = kvmalloc(_bytes, (gfp) & GFP_KERNEL); \
> @@ -52,64 +47,6 @@ do { \
> (heap)->data = NULL; \
> } while (0)
>
> -#define heap_swap(h, i, j) swap((h)->data[i], (h)->data[j])
> -
> -#define heap_sift(h, i, cmp) \
> -do { \
> - size_t _r, _j = i; \
> - \
> - for (; _j * 2 + 1 < (h)->used; _j = _r) { \
> - _r = _j * 2 + 1; \
> - if (_r + 1 < (h)->used && \
> - cmp((h)->data[_r], (h)->data[_r + 1])) \
> - _r++; \
> - \
> - if (cmp((h)->data[_r], (h)->data[_j])) \
> - break; \
> - heap_swap(h, _r, _j); \
> - } \
> -} while (0)
> -
> -#define heap_sift_down(h, i, cmp) \
> -do { \
> - while (i) { \
> - size_t p = (i - 1) / 2; \
> - if (cmp((h)->data[i], (h)->data[p])) \
> - break; \
> - heap_swap(h, i, p); \
> - i = p; \
> - } \
> -} while (0)
> -
> -#define heap_add(h, d, cmp) \
> -({ \
> - bool _r = !heap_full(h); \
> - if (_r) { \
> - size_t _i = (h)->used++; \
> - (h)->data[_i] = d; \
> - \
> - heap_sift_down(h, _i, cmp); \
> - heap_sift(h, _i, cmp); \
> - } \
> - _r; \
> -})
> -
> -#define heap_pop(h, d, cmp) \
> -({ \
> - bool _r = (h)->used; \
> - if (_r) { \
> - (d) = (h)->data[0]; \
> - (h)->used--; \
> - heap_swap(h, 0, (h)->used); \
> - heap_sift(h, 0, cmp); \
> - } \
> - _r; \
> -})
> -
> -#define heap_peek(h) ((h)->used ? (h)->data[0] : NULL)
> -
> -#define heap_full(h) ((h)->used == (h)->size)
> -
> #define DECLARE_FIFO(type, name) \
> struct { \
> size_t front, back, size, mask; \
> diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
> index 8827a6f130ad..c1d28e365910 100644
> --- a/drivers/md/bcache/writeback.c
> +++ b/drivers/md/bcache/writeback.c
> @@ -915,6 +915,7 @@ static int bch_dirty_init_thread(void *arg)
> k = p = NULL;
> prev_idx = 0;
>
> + min_heap_init(&iter.heap, NULL, MAX_BSETS);
> bch_btree_iter_init(&c->root->keys, &iter, NULL);
> k = bch_btree_iter_next_filter(&iter, &c->root->keys, bch_ptr_bad);
> BUG_ON(!k);
> @@ -984,6 +985,8 @@ void bch_sectors_dirty_init(struct bcache_device *d)
> struct cache_set *c = d->c;
> struct bch_dirty_init_state state;
>
> + min_heap_init(&iter.heap, NULL, MAX_BSETS);
> +
> retry_lock:
> b = c->root;
> rw_lock(0, b, b->level);
> --
> 2.34.1
>

--
Coly Li

--
Coly Li