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

Kuan-Wei Chiu
2024-04-06T16:48:57Z

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>
---
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