[PATCH v6 15/16] bcache: Remove heap-related macros and switch to generic min_heap

From: Kuan-Wei Chiu
Date: Fri May 24 2024 - 11:35:59 EST

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@xxxxxxxxx>
Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>
Acked-by: Coly Li <colyli@xxxxxxx>
---
Changes in v6:
- Rename the MIN_HEAP() macro to DEFINE_MIN_HEAP().

drivers/md/bcache/alloc.c | 64 +++++++++++++-----
drivers/md/bcache/bcache.h | 2 +-
drivers/md/bcache/bset.c | 124 ++++++++++++++++++++++------------
drivers/md/bcache/bset.h | 40 +++++------
drivers/md/bcache/btree.c | 69 +++++++++++--------
drivers/md/bcache/extents.c | 53 +++++++++------
drivers/md/bcache/movinggc.c | 41 ++++++++---
drivers/md/bcache/super.c | 3 +-
drivers/md/bcache/sysfs.c | 4 +-
drivers/md/bcache/util.h | 67 +-----------------
drivers/md/bcache/writeback.c | 13 ++--
11 files changed, 263 insertions(+), 217 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..654df8b7d344 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);
+ DEFINE_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 463eb13bd0b2..bd97d8626887 100644
--- a/drivers/md/bcache/bset.c
+++ b/drivers/md/bcache/bset.c
@@ -54,9 +54,11 @@ void bch_dump_bucket(struct btree_keys *b)
int __bch_count_data(struct btree_keys *b)
{
unsigned int ret = 0;
- struct btree_iter_stack iter;
+ 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);
@@ -67,9 +69,11 @@ void __bch_check_keys(struct btree_keys *b, const char *fmt, ...)
{
va_list args;
struct bkey *k, *p = NULL;
- struct btree_iter_stack iter;
+ 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);
@@ -879,12 +883,14 @@ unsigned int bch_btree_insert_key(struct btree_keys *b, struct bkey *k,
unsigned int status = BTREE_INSERT_STATUS_NO_INSERT;
struct bset *i = bset_tree_last(b)->data;
struct bkey *m, *prev = NULL;
- struct btree_iter_stack iter;
+ struct btree_iter iter;
struct bkey preceding_key_on_stack = ZERO_KEY;
struct bkey *preceding_key_p = &preceding_key_on_stack;

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
@@ -895,9 +901,9 @@ unsigned int bch_btree_insert_key(struct btree_keys *b, struct bkey *k,
else
preceding_key(k, &preceding_key_p);

- m = bch_btree_iter_stack_init(b, &iter, preceding_key_p);
+ m = bch_btree_iter_init(b, &iter, preceding_key_p);

- if (b->ops->insert_fixup(b, k, &iter.iter, replace_key))
+ if (b->ops->insert_fixup(b, k, &iter, replace_key))
return status;

status = BTREE_INSERT_STATUS_INSERT;
@@ -1077,79 +1083,102 @@ 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_stack_init(struct btree_keys *b,
- struct btree_iter_stack *iter,
- struct bkey *search,
- struct bset_tree *start)
+static struct bkey *__bch_btree_iter_init(struct btree_keys *b,
+ struct btree_iter *iter,
+ struct bkey *search,
+ struct bset_tree *start)
{
struct bkey *ret = NULL;

- iter->iter.size = ARRAY_SIZE(iter->stack_data);
- iter->iter.used = 0;
+ iter->heap.size = ARRAY_SIZE(iter->heap.preallocated);
+ iter->heap.nr = 0;

#ifdef CONFIG_BCACHE_DEBUG
- iter->iter.b = b;
+ iter->b = b;
#endif

for (; start <= bset_tree_last(b); start++) {
ret = bch_bset_search(b, start, search);
- bch_btree_iter_push(&iter->iter, ret, bset_bkey_last(start->data));
+ bch_btree_iter_push(iter, ret, bset_bkey_last(start->data));
}

return ret;
}

-struct bkey *bch_btree_iter_stack_init(struct btree_keys *b,
- struct btree_iter_stack *iter,
+struct bkey *bch_btree_iter_init(struct btree_keys *b,
+ struct btree_iter *iter,
struct bkey *search)
{
- return __bch_btree_iter_stack_init(b, iter, search, b->set);
+ return __bch_btree_iter_init(b, iter, search, b->set);
}

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)
@@ -1293,10 +1324,11 @@ void bch_btree_sort_partial(struct btree_keys *b, unsigned int start,
struct bset_sort_state *state)
{
size_t order = b->page_order, keys = 0;
- struct btree_iter_stack iter;
+ struct btree_iter iter;
int oldsize = bch_count_data(b);

- __bch_btree_iter_stack_init(b, &iter, NULL, &b->set[start]);
+ min_heap_init(&iter.heap, NULL, MAX_BSETS);
+ __bch_btree_iter_init(b, &iter, NULL, &b->set[start]);

if (start) {
unsigned int i;
@@ -1307,7 +1339,7 @@ void bch_btree_sort_partial(struct btree_keys *b, unsigned int start,
order = get_order(__set_bytes(b->set->data, keys));
}

- __btree_sort(b, &iter.iter, start, order, false, state);
+ __btree_sort(b, &iter, start, order, false, state);

EBUG_ON(oldsize >= 0 && bch_count_data(b) != oldsize);
}
@@ -1323,11 +1355,13 @@ void bch_btree_sort_into(struct btree_keys *b, struct btree_keys *new,
struct bset_sort_state *state)
{
uint64_t start_time = local_clock();
- struct btree_iter_stack iter;
+ struct btree_iter iter;
+
+ min_heap_init(&iter.heap, NULL, MAX_BSETS);

- bch_btree_iter_stack_init(b, &iter, NULL);
+ bch_btree_iter_init(b, &iter, NULL);

- btree_mergesort(b, new->set->data, &iter.iter, false, true);
+ btree_mergesort(b, new->set->data, &iter, false, true);

bch_time_stats_update(&state->time, start_time);

diff --git a/drivers/md/bcache/bset.h b/drivers/md/bcache/bset.h
index 011f6062c4c0..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,
@@ -312,23 +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[];
-};
-
-/* Fixed-size btree_iter that can be allocated on the stack */
-
-struct btree_iter_stack {
- struct btree_iter iter;
- struct btree_iter_set stack_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);
@@ -340,9 +335,9 @@ struct bkey *bch_btree_iter_next_filter(struct btree_iter *iter,

void bch_btree_iter_push(struct btree_iter *iter, struct bkey *k,
struct bkey *end);
-struct bkey *bch_btree_iter_stack_init(struct btree_keys *b,
- struct btree_iter_stack *iter,
- struct bkey *search);
+struct bkey *bch_btree_iter_init(struct btree_keys *b,
+ struct btree_iter *iter,
+ struct bkey *search);

struct bkey *__bch_bset_search(struct btree_keys *b, struct bset_tree *t,
const struct bkey *search);
@@ -357,14 +352,13 @@ static inline struct bkey *bch_bset_search(struct btree_keys *b,
return search ? __bch_bset_search(b, t, search) : t->data->start;
}

-#define for_each_key_filter(b, k, stack_iter, filter) \
- for (bch_btree_iter_stack_init((b), (stack_iter), NULL); \
- ((k) = bch_btree_iter_next_filter(&((stack_iter)->iter), (b), \
- filter));)
+#define for_each_key_filter(b, k, iter, filter) \
+ for (bch_btree_iter_init((b), (iter), NULL); \
+ ((k) = bch_btree_iter_next_filter((iter), (b), filter));)

-#define for_each_key(b, k, stack_iter) \
- for (bch_btree_iter_stack_init((b), (stack_iter), NULL); \
- ((k) = bch_btree_iter_next(&((stack_iter)->iter)));)
+#define for_each_key(b, k, iter) \
+ for (bch_btree_iter_init((b), (iter), NULL); \
+ ((k) = bch_btree_iter_next(iter));)

/* Sorting */

diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index d011a7154d33..ce9d729bc8ff 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -149,19 +149,19 @@ void bch_btree_node_read_done(struct btree *b)
{
const char *err = "bad btree header";
struct bset *i = btree_bset_first(b);
- struct btree_iter *iter;
+ struct btree_iter iter;

/*
* c->fill_iter can allocate an iterator with more memory space
* than static MAX_BSETS.
* 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.data = mempool_alloc(&b->c->fill_iter, GFP_NOIO);
+ 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;
+ iter.b = &b->keys;
#endif

if (!i->seq)
@@ -199,7 +199,7 @@ void bch_btree_node_read_done(struct btree *b)
if (i != b->keys.set[0].data && !i->keys)
goto err;

- bch_btree_iter_push(iter, i->start, bset_bkey_last(i));
+ bch_btree_iter_push(&iter, i->start, bset_bkey_last(i));

b->written += set_blocks(i, block_bytes(b->c->cache));
}
@@ -211,7 +211,7 @@ void bch_btree_node_read_done(struct btree *b)
if (i->seq == b->keys.set[0].data->seq)
goto err;

- bch_btree_sort_and_fix_extents(&b->keys, iter, &b->c->sort);
+ bch_btree_sort_and_fix_extents(&b->keys, &iter, &b->c->sort);

i = b->keys.set[0].data;
err = "short btree key";
@@ -223,7 +223,7 @@ void bch_btree_node_read_done(struct btree *b)
bch_bset_init_next(&b->keys, write_block(b),
bset_magic(&b->c->cache->sb));
out:
- mempool_free(iter, &b->c->fill_iter);
+ mempool_free(iter.heap.data, &b->c->fill_iter);
return;
err:
set_btree_node_io_error(b);
@@ -1309,9 +1309,11 @@ static bool btree_gc_mark_node(struct btree *b, struct gc_stat *gc)
uint8_t stale = 0;
unsigned int keys = 0, good_keys = 0;
struct bkey *k;
- struct btree_iter_stack iter;
+ 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) {
@@ -1570,9 +1572,11 @@ static int btree_gc_rewrite_node(struct btree *b, struct btree_op *op,
static unsigned int btree_gc_count_keys(struct btree *b)
{
struct bkey *k;
- struct btree_iter_stack iter;
+ 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);

@@ -1611,18 +1615,18 @@ static int btree_gc_recurse(struct btree *b, struct btree_op *op,
int ret = 0;
bool should_rewrite;
struct bkey *k;
- struct btree_iter_stack iter;
+ struct btree_iter iter;
struct gc_merge_info r[GC_MERGE_NODES];
struct gc_merge_info *i, *last = r + ARRAY_SIZE(r) - 1;

- bch_btree_iter_stack_init(&b->keys, &iter, &b->c->gc_done);
+ 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++)
i->b = ERR_PTR(-EINTR);

while (1) {
- k = bch_btree_iter_next_filter(&iter.iter, &b->keys,
- bch_ptr_bad);
+ k = bch_btree_iter_next_filter(&iter, &b->keys, bch_ptr_bad);
if (k) {
r->b = bch_btree_node_get(b->c, op, k, b->level - 1,
true, b);
@@ -1912,7 +1916,9 @@ static int bch_btree_check_recurse(struct btree *b, struct btree_op *op)
{
int ret = 0;
struct bkey *k, *p = NULL;
- struct btree_iter_stack iter;
+ 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);
@@ -1920,10 +1926,10 @@ static int bch_btree_check_recurse(struct btree *b, struct btree_op *op)
bch_initial_mark_key(b->c, b->level + 1, &b->key);

if (b->level) {
- bch_btree_iter_stack_init(&b->keys, &iter, NULL);
+ bch_btree_iter_init(&b->keys, &iter, NULL);

do {
- k = bch_btree_iter_next_filter(&iter.iter, &b->keys,
+ k = bch_btree_iter_next_filter(&iter, &b->keys,
bch_ptr_bad);
if (k) {
btree_node_prefetch(b, k);
@@ -1951,7 +1957,7 @@ static int bch_btree_check_thread(void *arg)
struct btree_check_info *info = arg;
struct btree_check_state *check_state = info->state;
struct cache_set *c = check_state->c;
- struct btree_iter_stack iter;
+ struct btree_iter iter;
struct bkey *k, *p;
int cur_idx, prev_idx, skip_nr;

@@ -1959,9 +1965,11 @@ 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_stack_init(&c->root->keys, &iter, NULL);
- k = bch_btree_iter_next_filter(&iter.iter, &c->root->keys, bch_ptr_bad);
+ 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);

p = k;
@@ -1979,7 +1987,7 @@ static int bch_btree_check_thread(void *arg)
skip_nr = cur_idx - prev_idx;

while (skip_nr) {
- k = bch_btree_iter_next_filter(&iter.iter,
+ k = bch_btree_iter_next_filter(&iter,
&c->root->keys,
bch_ptr_bad);
if (k)
@@ -2052,9 +2060,11 @@ int bch_btree_check(struct cache_set *c)
int ret = 0;
int i;
struct bkey *k = NULL;
- struct btree_iter_stack iter;
+ 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);
@@ -2548,11 +2558,12 @@ static int bch_btree_map_nodes_recurse(struct btree *b, struct btree_op *op,

if (b->level) {
struct bkey *k;
- struct btree_iter_stack iter;
+ struct btree_iter iter;

- bch_btree_iter_stack_init(&b->keys, &iter, from);
+ min_heap_init(&iter.heap, NULL, MAX_BSETS);
+ bch_btree_iter_init(&b->keys, &iter, from);

- while ((k = bch_btree_iter_next_filter(&iter.iter, &b->keys,
+ while ((k = bch_btree_iter_next_filter(&iter, &b->keys,
bch_ptr_bad))) {
ret = bcache_btree(map_nodes_recurse, k, b,
op, from, fn, flags);
@@ -2581,12 +2592,12 @@ int bch_btree_map_keys_recurse(struct btree *b, struct btree_op *op,
{
int ret = MAP_CONTINUE;
struct bkey *k;
- struct btree_iter_stack iter;
+ struct btree_iter iter;

- bch_btree_iter_stack_init(&b->keys, &iter, from);
+ min_heap_init(&iter.heap, NULL, MAX_BSETS);
+ bch_btree_iter_init(&b->keys, &iter, from);

- while ((k = bch_btree_iter_next_filter(&iter.iter, &b->keys,
- bch_ptr_bad))) {
+ while ((k = bch_btree_iter_next_filter(&iter, &b->keys, bch_ptr_bad))) {
ret = !b->level
? fn(op, b, k)
: bcache_btree(map_keys_recurse, k,
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/super.c b/drivers/md/bcache/super.c
index 4d11fc664cb0..1240d1b09e8c 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1914,8 +1914,7 @@ struct cache_set *bch_cache_set_alloc(struct cache_sb *sb)
INIT_LIST_HEAD(&c->btree_cache_freed);
INIT_LIST_HEAD(&c->data_buckets);

- iter_size = sizeof(struct btree_iter) +
- ((meta_bucket_pages(sb) * PAGE_SECTORS) / sb->block_size) *
+ iter_size = ((meta_bucket_pages(sb) * PAGE_SECTORS) / sb->block_size) *
sizeof(struct btree_iter_set);

c->devices = kcalloc(c->nr_uuids, sizeof(void *), GFP_KERNEL);
diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index 826b14cae4e5..e8f696cb58c0 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -660,7 +660,9 @@ static unsigned int bch_root_usage(struct cache_set *c)
unsigned int bytes = 0;
struct bkey *k;
struct btree *b;
- struct btree_iter_stack iter;
+ struct btree_iter iter;
+
+ min_heap_init(&iter.heap, NULL, MAX_BSETS);

goto lock_root;

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 792e070ccf38..c1d28e365910 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -908,15 +908,16 @@ static int bch_dirty_init_thread(void *arg)
struct dirty_init_thrd_info *info = arg;
struct bch_dirty_init_state *state = info->state;
struct cache_set *c = state->c;
- struct btree_iter_stack iter;
+ struct btree_iter iter;
struct bkey *k, *p;
int cur_idx, prev_idx, skip_nr;

k = p = NULL;
prev_idx = 0;

- bch_btree_iter_stack_init(&c->root->keys, &iter, NULL);
- k = bch_btree_iter_next_filter(&iter.iter, &c->root->keys, bch_ptr_bad);
+ 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);

p = k;
@@ -930,7 +931,7 @@ static int bch_dirty_init_thread(void *arg)
skip_nr = cur_idx - prev_idx;

while (skip_nr) {
- k = bch_btree_iter_next_filter(&iter.iter,
+ k = bch_btree_iter_next_filter(&iter,
&c->root->keys,
bch_ptr_bad);
if (k)
@@ -979,11 +980,13 @@ void bch_sectors_dirty_init(struct bcache_device *d)
int i;
struct btree *b = NULL;
struct bkey *k = NULL;
- struct btree_iter_stack iter;
+ struct btree_iter iter;
struct sectors_dirty_init op;
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