2024-04-25 14:19:11

by Kuan-Wei Chiu

[permalink] [raw]
Subject: [PATCH v4 00/16] treewide: Refactor heap related implementation

This patch series focuses on several adjustments related to heap
implementation. Firstly, a type-safe interface has been added to the
min_heap, along with the introduction of several new functions to
enhance its functionality. Additionally, the heap implementation for
bcache and bcachefs has been replaced with the generic min_heap
implementation from include/linux. Furthermore, several typos have been
corrected.

Previous discussion with Kent Overstreet:
https://lkml.kernel.org/ioyfizrzq7w7mjrqcadtzsfgpuntowtjdw5pgn4qhvsdp4mqqg@nrlek5vmisbu

Regards,
Kuan-Wei

---

You can preview this patch series on the 'refactor-heap-v4' branch of
the repository at the following link:

https://github.com/visitorckw/linux.git

Changes in v4:
- Change struct initializations to use designated initializers.
- Replace memcpy() with func->swp() in heap_del() due to issues with
set_backpointer in bcachefs when setting idx.
- Fix an error in ec_stripes_heap_swap() where
ec_stripes_heap_set_backpointer() should be called after swapping.

Changes in v3:
- Avoid heap->heap.nr to eliminate the nested types.
- Add MIN_HEAP_PREALLOCATED macro for preallocating some elements.
- Use min_heap_sift_up() in min_heap_push().
- Fix a bug in heap_del() where we should copy the last element to
'data + idx * element_size' instead of 'data'.
- Add testcases for heap_del().
- Fix bugs in bcache/bcachefs patches where the parameter types in
some compare functions should have been 'type **', but were
mistakenly written as 'type *'.

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().
- Update lib/test_min_heap.c to use min_heap_init().
- Refine the commit message for bcache and bcachefs.
- Adjust the order of patches in the patch series.

Link to v3: https://lore.kernel.org/[email protected]
Link to v2: https://lore.kernel.org/[email protected]
Link to v1: https://lkml.kernel.org/[email protected]

Kuan-Wei Chiu (16):
perf/core: Fix several typos
bcache: Fix typo
bcachefs: Fix typo
lib min_heap: Add type safe interface
lib min_heap: Add min_heap_init()
lib min_heap: Add min_heap_peek()
lib min_heap: Add min_heap_full()
lib min_heap: Add args for min_heap_callbacks
lib min_heap: Add min_heap_sift_up()
lib min_heap: Add min_heap_del()
lib min_heap: Update min_heap_push() and min_heap_pop() to return bool
values
lib min_heap: Rename min_heapify() to min_heap_sift_down()
lib min_heap: Update min_heap_push() to use min_heap_sift_up()
lib/test_min_heap: Add test for heap_del()
bcache: Remove heap-related macros and switch to generic min_heap
bcachefs: Remove heap-related macros and switch to generic min_heap

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.c | 2 +-
drivers/md/bcache/util.h | 67 +-----------
drivers/md/bcache/writeback.c | 3 +
drivers/md/dm-vdo/repair.c | 19 ++--
drivers/md/dm-vdo/slab-depot.c | 14 +--
fs/bcachefs/clock.c | 43 ++++++--
fs/bcachefs/clock_types.h | 2 +-
fs/bcachefs/ec.c | 76 ++++++++-----
fs/bcachefs/ec_types.h | 2 +-
fs/bcachefs/util.c | 2 +-
fs/bcachefs/util.h | 118 +--------------------
include/linux/min_heap.h | 188 +++++++++++++++++++++++++--------
kernel/events/core.c | 29 ++---
lib/test_min_heap.c | 75 +++++++++----
22 files changed, 522 insertions(+), 395 deletions(-)

--
2.34.1



2024-04-25 14:21:25

by Kuan-Wei Chiu

[permalink] [raw]
Subject: [PATCH v4 03/16] bcachefs: Fix typo

Replace 'utiility' with 'utility'.

Signed-off-by: Kuan-Wei Chiu <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
Reviewed-by: Randy Dunlap <[email protected]>
---
fs/bcachefs/util.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/bcachefs/util.c b/fs/bcachefs/util.c
index 92c6ad75e702..05ac1b3b0604 100644
--- a/fs/bcachefs/util.c
+++ b/fs/bcachefs/util.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
/*
- * random utiility code, for bcache but in theory not specific to bcache
+ * random utility code, for bcache but in theory not specific to bcache
*
* Copyright 2010, 2011 Kent Overstreet <[email protected]>
* Copyright 2012 Google, Inc.
--
2.34.1


2024-04-25 14:21:27

by Kuan-Wei Chiu

[permalink] [raw]
Subject: [PATCH v4 04/16] lib min_heap: Add type safe interface

Implement a type-safe interface for min_heap using strong type
pointers instead of void * in the data field. This change includes
adding small macro wrappers around functions, enabling the use of
__minheap_cast and __minheap_obj_size macros for type casting and
obtaining element size. This implementation removes the necessity of
passing element size in min_heap_callbacks. Additionally, introduce the
MIN_HEAP_PREALLOCATED macro for preallocating some elements.

Link: https://lkml.kernel.org/ioyfizrzq7w7mjrqcadtzsfgpuntowtjdw5pgn4qhvsdp4mqqg@nrlek5vmisbu
Signed-off-by: Kuan-Wei Chiu <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
---
Changes in v4:
- Change struct initializations to use designated initializers.

drivers/md/dm-vdo/repair.c | 9 ++--
drivers/md/dm-vdo/slab-depot.c | 5 +--
include/linux/min_heap.h | 79 ++++++++++++++++++++++------------
kernel/events/core.c | 11 ++---
lib/test_min_heap.c | 13 +++---
5 files changed, 70 insertions(+), 47 deletions(-)

diff --git a/drivers/md/dm-vdo/repair.c b/drivers/md/dm-vdo/repair.c
index defc9359f10e..48c266fa07b6 100644
--- a/drivers/md/dm-vdo/repair.c
+++ b/drivers/md/dm-vdo/repair.c
@@ -51,6 +51,8 @@ struct recovery_point {
bool increment_applied;
};

+MIN_HEAP(struct numbered_block_mapping, replay_heap);
+
struct repair_completion {
/* The completion header */
struct vdo_completion completion;
@@ -97,7 +99,7 @@ struct repair_completion {
* order, then original journal order. This permits efficient iteration over the journal
* entries in order.
*/
- struct min_heap replay_heap;
+ struct replay_heap replay_heap;
/* Fields tracking progress through the journal entries. */
struct numbered_block_mapping *current_entry;
struct numbered_block_mapping *current_unfetched_entry;
@@ -163,14 +165,13 @@ static void swap_mappings(void *item1, void *item2)
}

static const struct min_heap_callbacks repair_min_heap = {
- .elem_size = sizeof(struct numbered_block_mapping),
.less = mapping_is_less_than,
.swp = swap_mappings,
};

static struct numbered_block_mapping *sort_next_heap_element(struct repair_completion *repair)
{
- struct min_heap *heap = &repair->replay_heap;
+ struct replay_heap *heap = &repair->replay_heap;
struct numbered_block_mapping *last;

if (heap->nr == 0)
@@ -1117,7 +1118,7 @@ static void recover_block_map(struct vdo_completion *completion)
* Organize the journal entries into a binary heap so we can iterate over them in sorted
* order incrementally, avoiding an expensive sort call.
*/
- repair->replay_heap = (struct min_heap) {
+ repair->replay_heap = (struct replay_heap) {
.data = repair->entries,
.nr = repair->block_map_entry_count,
.size = repair->block_map_entry_count,
diff --git a/drivers/md/dm-vdo/slab-depot.c b/drivers/md/dm-vdo/slab-depot.c
index 46e4721e5b4f..f6ae6956f321 100644
--- a/drivers/md/dm-vdo/slab-depot.c
+++ b/drivers/md/dm-vdo/slab-depot.c
@@ -3309,7 +3309,6 @@ static void swap_slab_statuses(void *item1, void *item2)
}

static const struct min_heap_callbacks slab_status_min_heap = {
- .elem_size = sizeof(struct slab_status),
.less = slab_status_is_less_than,
.swp = swap_slab_statuses,
};
@@ -3509,7 +3508,7 @@ static int get_slab_statuses(struct block_allocator *allocator,
static int __must_check vdo_prepare_slabs_for_allocation(struct block_allocator *allocator)
{
struct slab_status current_slab_status;
- struct min_heap heap;
+ MIN_HEAP(struct slab_status, heap) heap;
int result;
struct slab_status *slab_statuses;
struct slab_depot *depot = allocator->depot;
@@ -3521,7 +3520,7 @@ static int __must_check vdo_prepare_slabs_for_allocation(struct block_allocator
return result;

/* Sort the slabs by cleanliness, then by emptiness hint. */
- heap = (struct min_heap) {
+ heap = (struct heap) {
.data = slab_statuses,
.nr = allocator->slab_count,
.size = allocator->slab_count,
diff --git a/include/linux/min_heap.h b/include/linux/min_heap.h
index d52daf45861b..87737cadb9a5 100644
--- a/include/linux/min_heap.h
+++ b/include/linux/min_heap.h
@@ -7,45 +7,53 @@
#include <linux/types.h>

/**
- * struct min_heap - Data structure to hold a min-heap.
- * @data: Start of array holding the heap elements.
+ * Data structure to hold a min-heap.
* @nr: Number of elements currently in the heap.
* @size: Maximum number of elements that can be held in current storage.
+ * @data: Pointer to the start of array holding the heap elements.
+ * @preallocated: Start of the static preallocated array holding the heap elements.
*/
-struct min_heap {
- void *data;
- int nr;
- int size;
-};
+#define MIN_HEAP_PREALLOCATED(_type, _name, _nr) \
+struct _name { \
+ int nr; \
+ int size; \
+ _type *data; \
+ _type preallocated[_nr]; \
+}
+
+#define MIN_HEAP(_type, _name) MIN_HEAP_PREALLOCATED(_type, _name, 0)
+
+typedef MIN_HEAP(char, min_heap_char) min_heap_char;
+
+#define __minheap_cast(_heap) (typeof((_heap)->data[0]) *)
+#define __minheap_obj_size(_heap) sizeof((_heap)->data[0])

/**
* struct min_heap_callbacks - Data/functions to customise the min_heap.
- * @elem_size: The nr of each element in bytes.
* @less: Partial order function for this heap.
* @swp: Swap elements function.
*/
struct min_heap_callbacks {
- int elem_size;
bool (*less)(const void *lhs, const void *rhs);
void (*swp)(void *lhs, void *rhs);
};

/* Sift the element at pos down the heap. */
static __always_inline
-void min_heapify(struct min_heap *heap, int pos,
+void __min_heapify(min_heap_char *heap, int pos, size_t elem_size,
const struct min_heap_callbacks *func)
{
void *left, *right;
void *data = heap->data;
- void *root = data + pos * func->elem_size;
+ void *root = data + pos * elem_size;
int i = pos, j;

/* Find the sift-down path all the way to the leaves. */
for (;;) {
if (i * 2 + 2 >= heap->nr)
break;
- left = data + (i * 2 + 1) * func->elem_size;
- right = data + (i * 2 + 2) * func->elem_size;
+ left = data + (i * 2 + 1) * elem_size;
+ right = data + (i * 2 + 2) * elem_size;
i = func->less(left, right) ? i * 2 + 1 : i * 2 + 2;
}

@@ -54,31 +62,37 @@ void min_heapify(struct min_heap *heap, int pos,
i = i * 2 + 1;

/* Backtrack to the correct location. */
- while (i != pos && func->less(root, data + i * func->elem_size))
+ while (i != pos && func->less(root, data + i * elem_size))
i = (i - 1) / 2;

/* Shift the element into its correct place. */
j = i;
while (i != pos) {
i = (i - 1) / 2;
- func->swp(data + i * func->elem_size, data + j * func->elem_size);
+ func->swp(data + i * elem_size, data + j * elem_size);
}
}

+#define min_heapify(_heap, _pos, _func) \
+ __min_heapify((min_heap_char *)_heap, _pos, __minheap_obj_size(_heap), _func)
+
/* Floyd's approach to heapification that is O(nr). */
static __always_inline
-void min_heapify_all(struct min_heap *heap,
+void __min_heapify_all(min_heap_char *heap, size_t elem_size,
const struct min_heap_callbacks *func)
{
int i;

for (i = heap->nr / 2 - 1; i >= 0; i--)
- min_heapify(heap, i, func);
+ __min_heapify(heap, i, elem_size, func);
}

+#define min_heapify_all(_heap, _func) \
+ __min_heapify_all((min_heap_char *)_heap, __minheap_obj_size(_heap), _func)
+
/* Remove minimum element from the heap, O(log2(nr)). */
static __always_inline
-void min_heap_pop(struct min_heap *heap,
+void __min_heap_pop(min_heap_char *heap, size_t elem_size,
const struct min_heap_callbacks *func)
{
void *data = heap->data;
@@ -88,27 +102,33 @@ void min_heap_pop(struct min_heap *heap,

/* Place last element at the root (position 0) and then sift down. */
heap->nr--;
- memcpy(data, data + (heap->nr * func->elem_size), func->elem_size);
- min_heapify(heap, 0, func);
+ memcpy(data, data + (heap->nr * elem_size), elem_size);
+ __min_heapify(heap, 0, elem_size, func);
}

+#define min_heap_pop(_heap, _func) \
+ __min_heap_pop((min_heap_char *)_heap, __minheap_obj_size(_heap), _func)
+
/*
* Remove the minimum element and then push the given element. The
* implementation performs 1 sift (O(log2(nr))) and is therefore more
* efficient than a pop followed by a push that does 2.
*/
static __always_inline
-void min_heap_pop_push(struct min_heap *heap,
- const void *element,
+void __min_heap_pop_push(min_heap_char *heap,
+ const void *element, size_t elem_size,
const struct min_heap_callbacks *func)
{
- memcpy(heap->data, element, func->elem_size);
- min_heapify(heap, 0, func);
+ memcpy(heap->data, element, elem_size);
+ __min_heapify(heap, 0, elem_size, func);
}

+#define min_heap_pop_push(_heap, _element, _func) \
+ __min_heap_pop_push((min_heap_char *)_heap, _element, __minheap_obj_size(_heap), _func)
+
/* Push an element on to the heap, O(log2(nr)). */
static __always_inline
-void min_heap_push(struct min_heap *heap, const void *element,
+void __min_heap_push(min_heap_char *heap, const void *element, size_t elem_size,
const struct min_heap_callbacks *func)
{
void *data = heap->data;
@@ -120,17 +140,20 @@ void min_heap_push(struct min_heap *heap, const void *element,

/* Place at the end of data. */
pos = heap->nr;
- memcpy(data + (pos * func->elem_size), element, func->elem_size);
+ memcpy(data + (pos * elem_size), element, elem_size);
heap->nr++;

/* Sift child at pos up. */
for (; pos > 0; pos = (pos - 1) / 2) {
- child = data + (pos * func->elem_size);
- parent = data + ((pos - 1) / 2) * func->elem_size;
+ child = data + (pos * elem_size);
+ parent = data + ((pos - 1) / 2) * elem_size;
if (func->less(parent, child))
break;
func->swp(parent, child);
}
}

+#define min_heap_push(_heap, _element, _func) \
+ __min_heap_push((min_heap_char *)_heap, _element, __minheap_obj_size(_heap), _func)
+
#endif /* _LINUX_MIN_HEAP_H */
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 10ac2db83f14..55930479599b 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3698,13 +3698,14 @@ static void swap_ptr(void *l, void *r)
swap(*lp, *rp);
}

+MIN_HEAP(struct perf_event *, perf_event_min_heap);
+
static const struct min_heap_callbacks perf_min_heap = {
- .elem_size = sizeof(struct perf_event *),
.less = perf_less_group_idx,
.swp = swap_ptr,
};

-static void __heap_add(struct min_heap *heap, struct perf_event *event)
+static void __heap_add(struct perf_event_min_heap *heap, struct perf_event *event)
{
struct perf_event **itrs = heap->data;

@@ -3738,7 +3739,7 @@ static noinline int visit_groups_merge(struct perf_event_context *ctx,
struct perf_cpu_context *cpuctx = NULL;
/* Space for per CPU and/or any CPU event iterators. */
struct perf_event *itrs[2];
- struct min_heap event_heap;
+ struct perf_event_min_heap event_heap;
struct perf_event **evt;
int ret;

@@ -3747,7 +3748,7 @@ static noinline int visit_groups_merge(struct perf_event_context *ctx,

if (!ctx->task) {
cpuctx = this_cpu_ptr(&perf_cpu_context);
- event_heap = (struct min_heap){
+ event_heap = (struct perf_event_min_heap){
.data = cpuctx->heap,
.nr = 0,
.size = cpuctx->heap_size,
@@ -3760,7 +3761,7 @@ static noinline int visit_groups_merge(struct perf_event_context *ctx,
css = &cpuctx->cgrp->css;
#endif
} else {
- event_heap = (struct min_heap){
+ event_heap = (struct perf_event_min_heap){
.data = itrs,
.nr = 0,
.size = ARRAY_SIZE(itrs),
diff --git a/lib/test_min_heap.c b/lib/test_min_heap.c
index 7b01b4387cfb..dd5c0fa862ab 100644
--- a/lib/test_min_heap.c
+++ b/lib/test_min_heap.c
@@ -11,6 +11,8 @@
#include <linux/printk.h>
#include <linux/random.h>

+MIN_HEAP(int, min_heap_test);
+
static __init bool less_than(const void *lhs, const void *rhs)
{
return *(int *)lhs < *(int *)rhs;
@@ -30,7 +32,7 @@ static __init void swap_ints(void *lhs, void *rhs)
}

static __init int pop_verify_heap(bool min_heap,
- struct min_heap *heap,
+ struct min_heap_test *heap,
const struct min_heap_callbacks *funcs)
{
int *values = heap->data;
@@ -63,13 +65,12 @@ static __init int test_heapify_all(bool min_heap)
{
int values[] = { 3, 1, 2, 4, 0x8000000, 0x7FFFFFF, 0,
-3, -1, -2, -4, 0x8000000, 0x7FFFFFF };
- struct min_heap heap = {
+ struct min_heap_test heap = {
.data = values,
.nr = ARRAY_SIZE(values),
.size = ARRAY_SIZE(values),
};
struct min_heap_callbacks funcs = {
- .elem_size = sizeof(int),
.less = min_heap ? less_than : greater_than,
.swp = swap_ints,
};
@@ -96,13 +97,12 @@ static __init int test_heap_push(bool min_heap)
const int data[] = { 3, 1, 2, 4, 0x80000000, 0x7FFFFFFF, 0,
-3, -1, -2, -4, 0x80000000, 0x7FFFFFFF };
int values[ARRAY_SIZE(data)];
- struct min_heap heap = {
+ struct min_heap_test heap = {
.data = values,
.nr = 0,
.size = ARRAY_SIZE(values),
};
struct min_heap_callbacks funcs = {
- .elem_size = sizeof(int),
.less = min_heap ? less_than : greater_than,
.swp = swap_ints,
};
@@ -129,13 +129,12 @@ static __init int test_heap_pop_push(bool min_heap)
const int data[] = { 3, 1, 2, 4, 0x80000000, 0x7FFFFFFF, 0,
-3, -1, -2, -4, 0x80000000, 0x7FFFFFFF };
int values[ARRAY_SIZE(data)];
- struct min_heap heap = {
+ struct min_heap_test heap = {
.data = values,
.nr = 0,
.size = ARRAY_SIZE(values),
};
struct min_heap_callbacks funcs = {
- .elem_size = sizeof(int),
.less = min_heap ? less_than : greater_than,
.swp = swap_ints,
};
--
2.34.1


2024-04-25 14:21:45

by Kuan-Wei Chiu

[permalink] [raw]
Subject: [PATCH v4 05/16] lib min_heap: Add min_heap_init()

Add min_heap_init() for initializing heap with data, nr, and size.

Signed-off-by: Kuan-Wei Chiu <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
---
include/linux/min_heap.h | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/include/linux/min_heap.h b/include/linux/min_heap.h
index 87737cadb9a5..f6b07fb8b2d3 100644
--- a/include/linux/min_heap.h
+++ b/include/linux/min_heap.h
@@ -38,6 +38,21 @@ struct min_heap_callbacks {
void (*swp)(void *lhs, void *rhs);
};

+/* Initialize a min-heap. */
+static __always_inline
+void __min_heap_init(min_heap_char *heap, void *data, int size)
+{
+ heap->nr = 0;
+ heap->size = size;
+ if (data)
+ heap->data = data;
+ else
+ heap->data = heap->preallocated;
+}
+
+#define min_heap_init(_heap, _data, _size) \
+ __min_heap_init((min_heap_char *)_heap, _data, _size)
+
/* Sift the element at pos down the heap. */
static __always_inline
void __min_heapify(min_heap_char *heap, int pos, size_t elem_size,
--
2.34.1


2024-04-25 14:22:31

by Kuan-Wei Chiu

[permalink] [raw]
Subject: [PATCH v4 07/16] lib min_heap: Add min_heap_full()

Add min_heap_full() which returns a boolean value indicating whether
the heap has reached its maximum capacity.

Signed-off-by: Kuan-Wei Chiu <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
---
include/linux/min_heap.h | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/include/linux/min_heap.h b/include/linux/min_heap.h
index 043de539bf71..d4ec7e749280 100644
--- a/include/linux/min_heap.h
+++ b/include/linux/min_heap.h
@@ -63,6 +63,16 @@ void *__min_heap_peek(struct min_heap_char *heap)
#define min_heap_peek(_heap) \
(__minheap_cast(_heap) __min_heap_peek((min_heap_char *)_heap))

+/* Check if the heap is full. */
+static __always_inline
+bool __min_heap_full(min_heap_char *heap)
+{
+ return heap->nr == heap->size;
+}
+
+#define min_heap_full(_heap) \
+ __min_heap_full((min_heap_char *)_heap)
+
/* Sift the element at pos down the heap. */
static __always_inline
void __min_heapify(min_heap_char *heap, int pos, size_t elem_size,
--
2.34.1


2024-04-25 14:22:52

by Kuan-Wei Chiu

[permalink] [raw]
Subject: [PATCH v4 09/16] lib min_heap: Add min_heap_sift_up()

Add min_heap_sift_up() to sift up the element at index 'idx' in the
heap.

Signed-off-by: Kuan-Wei Chiu <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
---
include/linux/min_heap.h | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)

diff --git a/include/linux/min_heap.h b/include/linux/min_heap.h
index 9391f7cc9da9..201f59cb3558 100644
--- a/include/linux/min_heap.h
+++ b/include/linux/min_heap.h
@@ -111,6 +111,26 @@ void __min_heapify(min_heap_char *heap, int pos, size_t elem_size,
#define min_heapify(_heap, _pos, _func, _args) \
__min_heapify((min_heap_char *)_heap, _pos, __minheap_obj_size(_heap), _func, _args)

+/* Sift up ith element from the heap, O(log2(nr)). */
+static __always_inline
+void __min_heap_sift_up(min_heap_char *heap, size_t elem_size, size_t idx,
+ const struct min_heap_callbacks *func, void *args)
+{
+ void *data = heap->data;
+ size_t parent;
+
+ while (idx) {
+ parent = (idx - 1) / 2;
+ if (func->less(data + parent * elem_size, data + idx * elem_size, args))
+ break;
+ func->swp(data + parent * elem_size, data + idx * elem_size, args);
+ idx = parent;
+ }
+}
+
+#define min_heap_sift_up(_heap, _idx, _func, _args) \
+ __min_heap_sift_up((min_heap_char *)_heap, __minheap_obj_size(_heap), _idx, _func, _args)
+
/* Floyd's approach to heapification that is O(nr). */
static __always_inline
void __min_heapify_all(min_heap_char *heap, size_t elem_size,
--
2.34.1


2024-04-25 14:23:34

by Kuan-Wei Chiu

[permalink] [raw]
Subject: [PATCH v4 11/16] lib min_heap: Update min_heap_push() and min_heap_pop() to return bool values

Modify the min_heap_push() and min_heap_pop() to return a boolean
value. They now return false when the operation fails and true when it
succeeds.

Signed-off-by: Kuan-Wei Chiu <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
---
include/linux/min_heap.h | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/linux/min_heap.h b/include/linux/min_heap.h
index c94f9d303205..2d080f85ad0d 100644
--- a/include/linux/min_heap.h
+++ b/include/linux/min_heap.h
@@ -147,18 +147,20 @@ void __min_heapify_all(min_heap_char *heap, size_t elem_size,

/* Remove minimum element from the heap, O(log2(nr)). */
static __always_inline
-void __min_heap_pop(min_heap_char *heap, size_t elem_size,
+bool __min_heap_pop(min_heap_char *heap, size_t elem_size,
const struct min_heap_callbacks *func, void *args)
{
void *data = heap->data;

if (WARN_ONCE(heap->nr <= 0, "Popping an empty heap"))
- return;
+ return false;

/* Place last element at the root (position 0) and then sift down. */
heap->nr--;
memcpy(data, data + (heap->nr * elem_size), elem_size);
__min_heapify(heap, 0, elem_size, func, args);
+
+ return true;
}

#define min_heap_pop(_heap, _func, _args) \
@@ -184,7 +186,7 @@ void __min_heap_pop_push(min_heap_char *heap,

/* Push an element on to the heap, O(log2(nr)). */
static __always_inline
-void __min_heap_push(min_heap_char *heap, const void *element, size_t elem_size,
+bool __min_heap_push(min_heap_char *heap, const void *element, size_t elem_size,
const struct min_heap_callbacks *func, void *args)
{
void *data = heap->data;
@@ -192,7 +194,7 @@ void __min_heap_push(min_heap_char *heap, const void *element, size_t elem_size,
int pos;

if (WARN_ONCE(heap->nr >= heap->size, "Pushing on a full heap"))
- return;
+ return false;

/* Place at the end of data. */
pos = heap->nr;
@@ -207,6 +209,8 @@ void __min_heap_push(min_heap_char *heap, const void *element, size_t elem_size,
break;
func->swp(parent, child, args);
}
+
+ return true;
}

#define min_heap_push(_heap, _element, _func, _args) \
--
2.34.1


2024-04-25 14:23:38

by Kuan-Wei Chiu

[permalink] [raw]
Subject: [PATCH v4 10/16] lib min_heap: Add min_heap_del()

Add min_heap_del() to delete the element at index 'idx' in the heap.

Signed-off-by: Kuan-Wei Chiu <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
---
Changes in v4:
- Replace memcpy() with func->swp() in heap_del() due to issues with
set_backpointer in bcachefs when setting idx.

include/linux/min_heap.h | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)

diff --git a/include/linux/min_heap.h b/include/linux/min_heap.h
index 201f59cb3558..c94f9d303205 100644
--- a/include/linux/min_heap.h
+++ b/include/linux/min_heap.h
@@ -212,4 +212,28 @@ void __min_heap_push(min_heap_char *heap, const void *element, size_t elem_size,
#define min_heap_push(_heap, _element, _func, _args) \
__min_heap_push((min_heap_char *)_heap, _element, __minheap_obj_size(_heap), _func, _args)

+/* Remove ith element from the heap, O(log2(nr)). */
+static __always_inline
+bool __min_heap_del(min_heap_char *heap, size_t elem_size, size_t idx,
+ const struct min_heap_callbacks *func, void *args)
+{
+ void *data = heap->data;
+
+ if (WARN_ONCE(heap->nr <= 0, "Popping an empty heap"))
+ return false;
+
+ /* Place last element at the root (position 0) and then sift down. */
+ heap->nr--;
+ if (idx == heap->nr)
+ return true;
+ func->swp(data + (idx * elem_size), data + (heap->nr * elem_size), args);
+ __min_heap_sift_up(heap, elem_size, idx, func, args);
+ __min_heapify(heap, idx, elem_size, func, args);
+
+ return true;
+}
+
+#define min_heap_del(_heap, _idx, _func, _args) \
+ __min_heap_del((min_heap_char *)_heap, __minheap_obj_size(_heap), _idx, _func, _args)
+
#endif /* _LINUX_MIN_HEAP_H */
--
2.34.1


2024-04-25 14:24:08

by Kuan-Wei Chiu

[permalink] [raw]
Subject: [PATCH v4 12/16] lib min_heap: Rename min_heapify() to min_heap_sift_down()

After adding min_heap_sift_up(), the naming convention has been
adjusted to maintain consistency with the min_heap_sift_up().
Consequently, min_heapify() has been renamed to min_heap_sift_down().

Link: https://lkml.kernel.org/CAP-5=fVcBAxt8Mw72=NCJPRJfjDaJcqk4rjbadgouAEAHz_q1A@mail.gmail.com
Signed-off-by: Kuan-Wei Chiu <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
---
drivers/md/dm-vdo/repair.c | 2 +-
include/linux/min_heap.h | 14 +++++++-------
kernel/events/core.c | 2 +-
3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/md/dm-vdo/repair.c b/drivers/md/dm-vdo/repair.c
index c1ed3ae823bf..941ac9eda8ca 100644
--- a/drivers/md/dm-vdo/repair.c
+++ b/drivers/md/dm-vdo/repair.c
@@ -183,7 +183,7 @@ static struct numbered_block_mapping *sort_next_heap_element(struct repair_compl
*/
last = &repair->entries[--heap->nr];
swap_mappings(heap->data, last, NULL);
- min_heapify(heap, 0, &repair_min_heap, NULL);
+ min_heap_sift_down(heap, 0, &repair_min_heap, NULL);
return last;
}

diff --git a/include/linux/min_heap.h b/include/linux/min_heap.h
index 2d080f85ad0d..f907c694e852 100644
--- a/include/linux/min_heap.h
+++ b/include/linux/min_heap.h
@@ -75,7 +75,7 @@ bool __min_heap_full(min_heap_char *heap)

/* Sift the element at pos down the heap. */
static __always_inline
-void __min_heapify(min_heap_char *heap, int pos, size_t elem_size,
+void __min_heap_sift_down(min_heap_char *heap, int pos, size_t elem_size,
const struct min_heap_callbacks *func, void *args)
{
void *left, *right;
@@ -108,8 +108,8 @@ void __min_heapify(min_heap_char *heap, int pos, size_t elem_size,
}
}

-#define min_heapify(_heap, _pos, _func, _args) \
- __min_heapify((min_heap_char *)_heap, _pos, __minheap_obj_size(_heap), _func, _args)
+#define min_heap_sift_down(_heap, _pos, _func, _args) \
+ __min_heap_sift_down((min_heap_char *)_heap, _pos, __minheap_obj_size(_heap), _func, _args)

/* Sift up ith element from the heap, O(log2(nr)). */
static __always_inline
@@ -139,7 +139,7 @@ void __min_heapify_all(min_heap_char *heap, size_t elem_size,
int i;

for (i = heap->nr / 2 - 1; i >= 0; i--)
- __min_heapify(heap, i, elem_size, func, args);
+ __min_heap_sift_down(heap, i, elem_size, func, args);
}

#define min_heapify_all(_heap, _func, _args) \
@@ -158,7 +158,7 @@ bool __min_heap_pop(min_heap_char *heap, size_t elem_size,
/* Place last element at the root (position 0) and then sift down. */
heap->nr--;
memcpy(data, data + (heap->nr * elem_size), elem_size);
- __min_heapify(heap, 0, elem_size, func, args);
+ __min_heap_sift_down(heap, 0, elem_size, func, args);

return true;
}
@@ -178,7 +178,7 @@ void __min_heap_pop_push(min_heap_char *heap,
void *args)
{
memcpy(heap->data, element, elem_size);
- __min_heapify(heap, 0, elem_size, func, args);
+ __min_heap_sift_down(heap, 0, elem_size, func, args);
}

#define min_heap_pop_push(_heap, _element, _func, _args) \
@@ -232,7 +232,7 @@ bool __min_heap_del(min_heap_char *heap, size_t elem_size, size_t idx,
return true;
func->swp(data + (idx * elem_size), data + (heap->nr * elem_size), args);
__min_heap_sift_up(heap, elem_size, idx, func, args);
- __min_heapify(heap, idx, elem_size, func, args);
+ __min_heap_sift_down(heap, idx, elem_size, func, args);

return true;
}
diff --git a/kernel/events/core.c b/kernel/events/core.c
index dfd7b5748cbb..82f329c8caea 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3792,7 +3792,7 @@ static noinline int visit_groups_merge(struct perf_event_context *ctx,

*evt = perf_event_groups_next(*evt, pmu);
if (*evt)
- min_heapify(&event_heap, 0, &perf_min_heap, NULL);
+ min_heap_sift_down(&event_heap, 0, &perf_min_heap, NULL);
else
min_heap_pop(&event_heap, &perf_min_heap, NULL);
}
--
2.34.1


2024-04-25 14:24:27

by Kuan-Wei Chiu

[permalink] [raw]
Subject: [PATCH v4 14/16] lib/test_min_heap: Add test for heap_del()

Add test cases for the min_heap_del() to ensure its functionality is
thoroughly tested.

Signed-off-by: Kuan-Wei Chiu <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
---
lib/test_min_heap.c | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)

diff --git a/lib/test_min_heap.c b/lib/test_min_heap.c
index 0b5037b4bd68..d40851cfd824 100644
--- a/lib/test_min_heap.c
+++ b/lib/test_min_heap.c
@@ -165,6 +165,40 @@ static __init int test_heap_pop_push(bool min_heap)
return err;
}

+static __init int test_heap_del(bool min_heap)
+{
+ int values[] = { 3, 1, 2, 4, 0x8000000, 0x7FFFFFF, 0,
+ -3, -1, -2, -4, 0x8000000, 0x7FFFFFF };
+ struct min_heap_test heap;
+
+ min_heap_init(&heap, values, ARRAY_SIZE(values));
+ heap.nr = ARRAY_SIZE(values);
+ struct min_heap_callbacks funcs = {
+ .less = min_heap ? less_than : greater_than,
+ .swp = swap_ints,
+ };
+ int i, err;
+
+ /* Test with known set of values. */
+ min_heapify_all(&heap, &funcs, NULL);
+ for (i = 0; i < ARRAY_SIZE(values) / 2; i++)
+ min_heap_del(&heap, get_random_u32() % heap.nr, &funcs, NULL);
+ err = pop_verify_heap(min_heap, &heap, &funcs);
+
+
+ /* Test with randomly generated values. */
+ heap.nr = ARRAY_SIZE(values);
+ for (i = 0; i < heap.nr; i++)
+ values[i] = get_random_u32();
+ min_heapify_all(&heap, &funcs, NULL);
+
+ for (i = 0; i < ARRAY_SIZE(values) / 2; i++)
+ min_heap_del(&heap, get_random_u32() % heap.nr, &funcs, NULL);
+ err += pop_verify_heap(min_heap, &heap, &funcs);
+
+ return err;
+}
+
static int __init test_min_heap_init(void)
{
int err = 0;
@@ -175,6 +209,8 @@ static int __init test_min_heap_init(void)
err += test_heap_push(false);
err += test_heap_pop_push(true);
err += test_heap_pop_push(false);
+ err += test_heap_del(true);
+ err += test_heap_del(false);
if (err) {
pr_err("test failed with %d errors\n", err);
return -EINVAL;
--
2.34.1


2024-04-25 14:24:45

by Kuan-Wei Chiu

[permalink] [raw]
Subject: [PATCH v4 15/16] bcache: Remove heap-related macros and switch to generic min_heap

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 <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
Acked-by: Coly Li <[email protected]>
---
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


2024-04-25 14:27:14

by Kuan-Wei Chiu

[permalink] [raw]
Subject: [PATCH v4 02/16] bcache: Fix typo

Replace 'utiility' with 'utility'.

Signed-off-by: Kuan-Wei Chiu <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
Reviewed-by: Randy Dunlap <[email protected]>
---
drivers/md/bcache/util.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/bcache/util.c b/drivers/md/bcache/util.c
index ae380bc3992e..410d8cb49e50 100644
--- a/drivers/md/bcache/util.c
+++ b/drivers/md/bcache/util.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
/*
- * random utiility code, for bcache but in theory not specific to bcache
+ * random utility code, for bcache but in theory not specific to bcache
*
* Copyright 2010, 2011 Kent Overstreet <[email protected]>
* Copyright 2012 Google, Inc.
--
2.34.1


2024-04-25 14:42:37

by Kuan-Wei Chiu

[permalink] [raw]
Subject: [PATCH v4 01/16] perf/core: Fix several typos

Replace 'artifically' with 'artificially'.
Replace 'irrespecive' with 'irrespective'.
Replace 'futher' with 'further'.
Replace 'sufficent' with 'sufficient'.

Signed-off-by: Kuan-Wei Chiu <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
Reviewed-by: Randy Dunlap <[email protected]>
---
kernel/events/core.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 724e6d7e128f..10ac2db83f14 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -534,7 +534,7 @@ void perf_sample_event_took(u64 sample_len_ns)
__this_cpu_write(running_sample_length, running_len);

/*
- * Note: this will be biased artifically low until we have
+ * Note: this will be biased artificially low until we have
* seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
* from having to maintain a count.
*/
@@ -596,10 +596,10 @@ static inline u64 perf_event_clock(struct perf_event *event)
*
* Event groups make things a little more complicated, but not terribly so. The
* rules for a group are that if the group leader is OFF the entire group is
- * OFF, irrespecive of what the group member states are. This results in
+ * OFF, irrespective of what the group member states are. This results in
* __perf_effective_state().
*
- * A futher ramification is that when a group leader flips between OFF and
+ * A further ramification is that when a group leader flips between OFF and
* !OFF, we need to update all group member times.
*
*
@@ -891,7 +891,7 @@ static int perf_cgroup_ensure_storage(struct perf_event *event,
int cpu, heap_size, ret = 0;

/*
- * Allow storage to have sufficent space for an iterator for each
+ * Allow storage to have sufficient space for an iterator for each
* possibly nested cgroup plus an iterator for events with no cgroup.
*/
for (heap_size = 1; css; css = css->parent)
--
2.34.1


2024-04-25 14:45:58

by Kuan-Wei Chiu

[permalink] [raw]
Subject: [PATCH v4 06/16] lib min_heap: Add min_heap_peek()

Add min_heap_peek() function to retrieve a pointer to the smallest
element. The pointer is cast to the appropriate type of heap elements.

Signed-off-by: Kuan-Wei Chiu <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
---
include/linux/min_heap.h | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/include/linux/min_heap.h b/include/linux/min_heap.h
index f6b07fb8b2d3..043de539bf71 100644
--- a/include/linux/min_heap.h
+++ b/include/linux/min_heap.h
@@ -53,6 +53,16 @@ void __min_heap_init(min_heap_char *heap, void *data, int size)
#define min_heap_init(_heap, _data, _size) \
__min_heap_init((min_heap_char *)_heap, _data, _size)

+/* Get the minimum element from the heap. */
+static __always_inline
+void *__min_heap_peek(struct min_heap_char *heap)
+{
+ return heap->nr ? heap->data : NULL;
+}
+
+#define min_heap_peek(_heap) \
+ (__minheap_cast(_heap) __min_heap_peek((min_heap_char *)_heap))
+
/* Sift the element at pos down the heap. */
static __always_inline
void __min_heapify(min_heap_char *heap, int pos, size_t elem_size,
--
2.34.1


2024-04-25 14:46:37

by Kuan-Wei Chiu

[permalink] [raw]
Subject: [PATCH v4 08/16] lib min_heap: Add args for min_heap_callbacks

Add a third parameter 'args' for the 'less' and 'swp' functions in the
'struct min_heap_callbacks'. This additional parameter allows these
comparison and swap functions to handle extra arguments when necessary.

Signed-off-by: Kuan-Wei Chiu <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
---
drivers/md/dm-vdo/repair.c | 10 +++----
drivers/md/dm-vdo/slab-depot.c | 9 +++---
include/linux/min_heap.h | 51 +++++++++++++++++-----------------
kernel/events/core.c | 10 +++----
lib/test_min_heap.c | 26 ++++++++---------
5 files changed, 54 insertions(+), 52 deletions(-)

diff --git a/drivers/md/dm-vdo/repair.c b/drivers/md/dm-vdo/repair.c
index 48c266fa07b6..c1ed3ae823bf 100644
--- a/drivers/md/dm-vdo/repair.c
+++ b/drivers/md/dm-vdo/repair.c
@@ -137,7 +137,7 @@ struct repair_completion {
* to sort by slot while still ensuring we replay all entries with the same slot in the exact order
* as they appeared in the journal.
*/
-static bool mapping_is_less_than(const void *item1, const void *item2)
+static bool mapping_is_less_than(const void *item1, const void *item2, void __always_unused *args)
{
const struct numbered_block_mapping *mapping1 =
(const struct numbered_block_mapping *) item1;
@@ -156,7 +156,7 @@ static bool mapping_is_less_than(const void *item1, const void *item2)
return 0;
}

-static void swap_mappings(void *item1, void *item2)
+static void swap_mappings(void *item1, void *item2, void __always_unused *args)
{
struct numbered_block_mapping *mapping1 = item1;
struct numbered_block_mapping *mapping2 = item2;
@@ -182,8 +182,8 @@ static struct numbered_block_mapping *sort_next_heap_element(struct repair_compl
* restore the heap invariant, and return a pointer to the popped element.
*/
last = &repair->entries[--heap->nr];
- swap_mappings(heap->data, last);
- min_heapify(heap, 0, &repair_min_heap);
+ swap_mappings(heap->data, last, NULL);
+ min_heapify(heap, 0, &repair_min_heap, NULL);
return last;
}

@@ -1123,7 +1123,7 @@ static void recover_block_map(struct vdo_completion *completion)
.nr = repair->block_map_entry_count,
.size = repair->block_map_entry_count,
};
- min_heapify_all(&repair->replay_heap, &repair_min_heap);
+ min_heapify_all(&repair->replay_heap, &repair_min_heap, NULL);

vdo_log_info("Replaying %zu recovery entries into block map",
repair->block_map_entry_count);
diff --git a/drivers/md/dm-vdo/slab-depot.c b/drivers/md/dm-vdo/slab-depot.c
index f6ae6956f321..2739f5b1f8bd 100644
--- a/drivers/md/dm-vdo/slab-depot.c
+++ b/drivers/md/dm-vdo/slab-depot.c
@@ -3288,7 +3288,8 @@ int vdo_release_block_reference(struct block_allocator *allocator,
* Thus, the ordering is reversed from the usual sense since min_heap returns smaller elements
* before larger ones.
*/
-static bool slab_status_is_less_than(const void *item1, const void *item2)
+static bool slab_status_is_less_than(const void *item1, const void *item2,
+ void __always_unused *args)
{
const struct slab_status *info1 = item1;
const struct slab_status *info2 = item2;
@@ -3300,7 +3301,7 @@ static bool slab_status_is_less_than(const void *item1, const void *item2)
return info1->slab_number < info2->slab_number;
}

-static void swap_slab_statuses(void *item1, void *item2)
+static void swap_slab_statuses(void *item1, void *item2, void __always_unused *args)
{
struct slab_status *info1 = item1;
struct slab_status *info2 = item2;
@@ -3525,7 +3526,7 @@ static int __must_check vdo_prepare_slabs_for_allocation(struct block_allocator
.nr = allocator->slab_count,
.size = allocator->slab_count,
};
- min_heapify_all(&heap, &slab_status_min_heap);
+ min_heapify_all(&heap, &slab_status_min_heap, NULL);

while (heap.nr > 0) {
bool high_priority;
@@ -3533,7 +3534,7 @@ static int __must_check vdo_prepare_slabs_for_allocation(struct block_allocator
struct slab_journal *journal;

current_slab_status = slab_statuses[0];
- min_heap_pop(&heap, &slab_status_min_heap);
+ min_heap_pop(&heap, &slab_status_min_heap, NULL);
slab = depot->slabs[current_slab_status.slab_number];

if ((depot->load_type == VDO_SLAB_DEPOT_REBUILD_LOAD) ||
diff --git a/include/linux/min_heap.h b/include/linux/min_heap.h
index d4ec7e749280..9391f7cc9da9 100644
--- a/include/linux/min_heap.h
+++ b/include/linux/min_heap.h
@@ -34,8 +34,8 @@ typedef MIN_HEAP(char, min_heap_char) min_heap_char;
* @swp: Swap elements function.
*/
struct min_heap_callbacks {
- bool (*less)(const void *lhs, const void *rhs);
- void (*swp)(void *lhs, void *rhs);
+ bool (*less)(const void *lhs, const void *rhs, void *args);
+ void (*swp)(void *lhs, void *rhs, void *args);
};

/* Initialize a min-heap. */
@@ -76,7 +76,7 @@ bool __min_heap_full(min_heap_char *heap)
/* Sift the element at pos down the heap. */
static __always_inline
void __min_heapify(min_heap_char *heap, int pos, size_t elem_size,
- const struct min_heap_callbacks *func)
+ const struct min_heap_callbacks *func, void *args)
{
void *left, *right;
void *data = heap->data;
@@ -89,7 +89,7 @@ void __min_heapify(min_heap_char *heap, int pos, size_t elem_size,
break;
left = data + (i * 2 + 1) * elem_size;
right = data + (i * 2 + 2) * elem_size;
- i = func->less(left, right) ? i * 2 + 1 : i * 2 + 2;
+ i = func->less(left, right, args) ? i * 2 + 1 : i * 2 + 2;
}

/* Special case for the last leaf with no sibling. */
@@ -97,38 +97,38 @@ void __min_heapify(min_heap_char *heap, int pos, size_t elem_size,
i = i * 2 + 1;

/* Backtrack to the correct location. */
- while (i != pos && func->less(root, data + i * elem_size))
+ while (i != pos && func->less(root, data + i * elem_size, args))
i = (i - 1) / 2;

/* Shift the element into its correct place. */
j = i;
while (i != pos) {
i = (i - 1) / 2;
- func->swp(data + i * elem_size, data + j * elem_size);
+ func->swp(data + i * elem_size, data + j * elem_size, args);
}
}

-#define min_heapify(_heap, _pos, _func) \
- __min_heapify((min_heap_char *)_heap, _pos, __minheap_obj_size(_heap), _func)
+#define min_heapify(_heap, _pos, _func, _args) \
+ __min_heapify((min_heap_char *)_heap, _pos, __minheap_obj_size(_heap), _func, _args)

/* Floyd's approach to heapification that is O(nr). */
static __always_inline
void __min_heapify_all(min_heap_char *heap, size_t elem_size,
- const struct min_heap_callbacks *func)
+ const struct min_heap_callbacks *func, void *args)
{
int i;

for (i = heap->nr / 2 - 1; i >= 0; i--)
- __min_heapify(heap, i, elem_size, func);
+ __min_heapify(heap, i, elem_size, func, args);
}

-#define min_heapify_all(_heap, _func) \
- __min_heapify_all((min_heap_char *)_heap, __minheap_obj_size(_heap), _func)
+#define min_heapify_all(_heap, _func, _args) \
+ __min_heapify_all((min_heap_char *)_heap, __minheap_obj_size(_heap), _func, _args)

/* Remove minimum element from the heap, O(log2(nr)). */
static __always_inline
void __min_heap_pop(min_heap_char *heap, size_t elem_size,
- const struct min_heap_callbacks *func)
+ const struct min_heap_callbacks *func, void *args)
{
void *data = heap->data;

@@ -138,11 +138,11 @@ void __min_heap_pop(min_heap_char *heap, size_t elem_size,
/* Place last element at the root (position 0) and then sift down. */
heap->nr--;
memcpy(data, data + (heap->nr * elem_size), elem_size);
- __min_heapify(heap, 0, elem_size, func);
+ __min_heapify(heap, 0, elem_size, func, args);
}

-#define min_heap_pop(_heap, _func) \
- __min_heap_pop((min_heap_char *)_heap, __minheap_obj_size(_heap), _func)
+#define min_heap_pop(_heap, _func, _args) \
+ __min_heap_pop((min_heap_char *)_heap, __minheap_obj_size(_heap), _func, _args)

/*
* Remove the minimum element and then push the given element. The
@@ -152,19 +152,20 @@ void __min_heap_pop(min_heap_char *heap, size_t elem_size,
static __always_inline
void __min_heap_pop_push(min_heap_char *heap,
const void *element, size_t elem_size,
- const struct min_heap_callbacks *func)
+ const struct min_heap_callbacks *func,
+ void *args)
{
memcpy(heap->data, element, elem_size);
- __min_heapify(heap, 0, elem_size, func);
+ __min_heapify(heap, 0, elem_size, func, args);
}

-#define min_heap_pop_push(_heap, _element, _func) \
- __min_heap_pop_push((min_heap_char *)_heap, _element, __minheap_obj_size(_heap), _func)
+#define min_heap_pop_push(_heap, _element, _func, _args) \
+ __min_heap_pop_push((min_heap_char *)_heap, _element, __minheap_obj_size(_heap), _func, _args)

/* Push an element on to the heap, O(log2(nr)). */
static __always_inline
void __min_heap_push(min_heap_char *heap, const void *element, size_t elem_size,
- const struct min_heap_callbacks *func)
+ const struct min_heap_callbacks *func, void *args)
{
void *data = heap->data;
void *child, *parent;
@@ -182,13 +183,13 @@ void __min_heap_push(min_heap_char *heap, const void *element, size_t elem_size,
for (; pos > 0; pos = (pos - 1) / 2) {
child = data + (pos * elem_size);
parent = data + ((pos - 1) / 2) * elem_size;
- if (func->less(parent, child))
+ if (func->less(parent, child, args))
break;
- func->swp(parent, child);
+ func->swp(parent, child, args);
}
}

-#define min_heap_push(_heap, _element, _func) \
- __min_heap_push((min_heap_char *)_heap, _element, __minheap_obj_size(_heap), _func)
+#define min_heap_push(_heap, _element, _func, _args) \
+ __min_heap_push((min_heap_char *)_heap, _element, __minheap_obj_size(_heap), _func, _args)

#endif /* _LINUX_MIN_HEAP_H */
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 55930479599b..dfd7b5748cbb 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3683,7 +3683,7 @@ void __perf_event_task_sched_out(struct task_struct *task,
perf_cgroup_switch(next);
}

-static bool perf_less_group_idx(const void *l, const void *r)
+static bool perf_less_group_idx(const void *l, const void *r, void __always_unused *args)
{
const struct perf_event *le = *(const struct perf_event **)l;
const struct perf_event *re = *(const struct perf_event **)r;
@@ -3691,7 +3691,7 @@ static bool perf_less_group_idx(const void *l, const void *r)
return le->group_index < re->group_index;
}

-static void swap_ptr(void *l, void *r)
+static void swap_ptr(void *l, void *r, void __always_unused *args)
{
void **lp = l, **rp = r;

@@ -3783,7 +3783,7 @@ static noinline int visit_groups_merge(struct perf_event_context *ctx,
perf_assert_pmu_disabled((*evt)->pmu_ctx->pmu);
}

- min_heapify_all(&event_heap, &perf_min_heap);
+ min_heapify_all(&event_heap, &perf_min_heap, NULL);

while (event_heap.nr) {
ret = func(*evt, data);
@@ -3792,9 +3792,9 @@ static noinline int visit_groups_merge(struct perf_event_context *ctx,

*evt = perf_event_groups_next(*evt, pmu);
if (*evt)
- min_heapify(&event_heap, 0, &perf_min_heap);
+ min_heapify(&event_heap, 0, &perf_min_heap, NULL);
else
- min_heap_pop(&event_heap, &perf_min_heap);
+ min_heap_pop(&event_heap, &perf_min_heap, NULL);
}

return 0;
diff --git a/lib/test_min_heap.c b/lib/test_min_heap.c
index dd5c0fa862ab..0b5037b4bd68 100644
--- a/lib/test_min_heap.c
+++ b/lib/test_min_heap.c
@@ -13,17 +13,17 @@

MIN_HEAP(int, min_heap_test);

-static __init bool less_than(const void *lhs, const void *rhs)
+static __init bool less_than(const void *lhs, const void *rhs, void __always_unused *args)
{
return *(int *)lhs < *(int *)rhs;
}

-static __init bool greater_than(const void *lhs, const void *rhs)
+static __init bool greater_than(const void *lhs, const void *rhs, void __always_unused *args)
{
return *(int *)lhs > *(int *)rhs;
}

-static __init void swap_ints(void *lhs, void *rhs)
+static __init void swap_ints(void *lhs, void *rhs, void __always_unused *args)
{
int temp = *(int *)lhs;

@@ -40,7 +40,7 @@ static __init int pop_verify_heap(bool min_heap,
int last;

last = values[0];
- min_heap_pop(heap, funcs);
+ min_heap_pop(heap, funcs, NULL);
while (heap->nr > 0) {
if (min_heap) {
if (last > values[0]) {
@@ -56,7 +56,7 @@ static __init int pop_verify_heap(bool min_heap,
}
}
last = values[0];
- min_heap_pop(heap, funcs);
+ min_heap_pop(heap, funcs, NULL);
}
return err;
}
@@ -77,7 +77,7 @@ static __init int test_heapify_all(bool min_heap)
int i, err;

/* Test with known set of values. */
- min_heapify_all(&heap, &funcs);
+ min_heapify_all(&heap, &funcs, NULL);
err = pop_verify_heap(min_heap, &heap, &funcs);


@@ -86,7 +86,7 @@ static __init int test_heapify_all(bool min_heap)
for (i = 0; i < heap.nr; i++)
values[i] = get_random_u32();

- min_heapify_all(&heap, &funcs);
+ min_heapify_all(&heap, &funcs, NULL);
err += pop_verify_heap(min_heap, &heap, &funcs);

return err;
@@ -110,14 +110,14 @@ static __init int test_heap_push(bool min_heap)

/* Test with known set of values copied from data. */
for (i = 0; i < ARRAY_SIZE(data); i++)
- min_heap_push(&heap, &data[i], &funcs);
+ min_heap_push(&heap, &data[i], &funcs, NULL);

err = pop_verify_heap(min_heap, &heap, &funcs);

/* Test with randomly generated values. */
while (heap.nr < heap.size) {
temp = get_random_u32();
- min_heap_push(&heap, &temp, &funcs);
+ min_heap_push(&heap, &temp, &funcs, NULL);
}
err += pop_verify_heap(min_heap, &heap, &funcs);

@@ -143,22 +143,22 @@ static __init int test_heap_pop_push(bool min_heap)
/* Fill values with data to pop and replace. */
temp = min_heap ? 0x80000000 : 0x7FFFFFFF;
for (i = 0; i < ARRAY_SIZE(data); i++)
- min_heap_push(&heap, &temp, &funcs);
+ min_heap_push(&heap, &temp, &funcs, NULL);

/* Test with known set of values copied from data. */
for (i = 0; i < ARRAY_SIZE(data); i++)
- min_heap_pop_push(&heap, &data[i], &funcs);
+ min_heap_pop_push(&heap, &data[i], &funcs, NULL);

err = pop_verify_heap(min_heap, &heap, &funcs);

heap.nr = 0;
for (i = 0; i < ARRAY_SIZE(data); i++)
- min_heap_push(&heap, &temp, &funcs);
+ min_heap_push(&heap, &temp, &funcs, NULL);

/* Test with randomly generated values. */
for (i = 0; i < ARRAY_SIZE(data); i++) {
temp = get_random_u32();
- min_heap_pop_push(&heap, &temp, &funcs);
+ min_heap_pop_push(&heap, &temp, &funcs, NULL);
}
err += pop_verify_heap(min_heap, &heap, &funcs);

--
2.34.1


2024-04-25 14:48:05

by Kuan-Wei Chiu

[permalink] [raw]
Subject: [PATCH v4 16/16] bcachefs: Remove heap-related macros and switch to generic min_heap

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 <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
---
Changes in v4:
- Fix an error in ec_stripes_heap_swap() where
ec_stripes_heap_set_backpointer() should be called after swapping.

fs/bcachefs/clock.c | 43 ++++++++++----
fs/bcachefs/clock_types.h | 2 +-
fs/bcachefs/ec.c | 76 ++++++++++++++++--------
fs/bcachefs/ec_types.h | 2 +-
fs/bcachefs/util.h | 118 +-------------------------------------
5 files changed, 87 insertions(+), 154 deletions(-)

diff --git a/fs/bcachefs/clock.c b/fs/bcachefs/clock.c
index 363644451106..3ec64fe6a064 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++)
+ for (i = 0; i < clock->timers.nr; i++)
if (clock->timers.data[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++)
+ for (i = 0; i < clock->timers.nr; i++)
if (clock->timers.data[i] == timer) {
- heap_del(&clock->timers, i, io_timer_cmp, NULL);
+ min_heap_del(&clock->timers, i, &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 &&
+ if (clock->timers.nr &&
time_after_eq(now, clock->timers.data[0]->expire))
- heap_pop(&clock->timers, ret, io_timer_cmp, NULL);
+ min_heap_pop(&clock->timers, &callbacks, NULL);

spin_unlock(&clock->timer_lock);

@@ -161,7 +182,7 @@ 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.nr; i++)
prt_printf(out, "%ps:\t%li\n",
clock->timers.data[i]->fn,
clock->timers.data[i]->expire - now);
diff --git a/fs/bcachefs/clock_types.h b/fs/bcachefs/clock_types.h
index 5fae0012d808..59716e148645 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 556a217108d3..0831e745dd12 100644
--- a/fs/bcachefs/ec.c
+++ b/fs/bcachefs/ec.c
@@ -868,8 +868,8 @@ static int __ec_stripe_mem_alloc(struct bch_fs *c, size_t idx, gfp_t gfp)

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;
+ memcpy(n.data, h->data, h->nr * sizeof(h->data[0]));
+ n.nr = h->nr;
swap(*h, n);
}
mutex_unlock(&c->ec_stripes_heap_lock);
@@ -960,7 +960,7 @@ static u64 stripe_idx_to_delete(struct bch_fs *c)

lockdep_assert_held(&c->ec_stripes_heap_lock);

- if (h->used &&
+ if (h->nr &&
h->data[0].blocks_nonempty == 0 &&
!bch2_stripe_is_open(c, h->data[0].idx))
return h->data[0].idx;
@@ -968,14 +968,6 @@ static u64 stripe_idx_to_delete(struct bch_fs *c)
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)
-{
- 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,
size_t i)
{
@@ -984,39 +976,71 @@ static inline void ec_stripes_heap_set_backpointer(ec_stripes_heap *h,
genradix_ptr(&c->stripes, h->data[i].idx)->heap_idx = i;
}

+static inline bool ec_stripes_heap_cmp(const void *l, const void *r, void __always_unused *args)
+{
+ 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_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 - _h->data;
+ size_t j = _r - _h->data;
+
+ swap(*_l, *_r);
+
+ ec_stripes_heap_set_backpointer(_h, i);
+ ec_stripes_heap_set_backpointer(_h, j);
+}
+
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(m->heap_idx >= h->nr);
BUG_ON(h->data[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.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);
@@ -1025,6 +1049,10 @@ void bch2_stripes_heap_insert(struct bch_fs *c,
void bch2_stripes_heap_update(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,
+ };
ec_stripes_heap *h = &c->ec_stripes_heap;
bool do_deletes;
size_t i;
@@ -1035,10 +1063,8 @@ void bch2_stripes_heap_update(struct bch_fs *c,
h->data[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);

@@ -1830,7 +1856,7 @@ 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->nr; heap_idx++) {
/* No blocks worth reusing, stripe will just be deleted: */
if (!h->data[heap_idx].blocks_nonempty)
continue;
@@ -2161,7 +2187,7 @@ 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++) {
+ for (i = 0; i < min_t(size_t, h->nr, 50); i++) {
m = genradix_ptr(&c->stripes, h->data[i].idx);

prt_printf(out, "%zu %u/%u+%u", h->data[i].idx,
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 5cf885b09986..d5a1f1e29013 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>
@@ -54,17 +55,9 @@ 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)->nr = 0; \
(heap)->size = (_size); \
(heap)->data = kvmalloc((heap)->size * sizeof((heap)->data[0]),\
(gfp)); \
@@ -76,113 +69,6 @@ do { \
(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; \
-})
-
-#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) \
-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); \
- } \
-} 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


2024-04-25 14:48:32

by Kuan-Wei Chiu

[permalink] [raw]
Subject: [PATCH v4 13/16] lib min_heap: Update min_heap_push() to use min_heap_sift_up()

Update min_heap_push() to use min_heap_sift_up() rather than its origin
inline version.

Signed-off-by: Kuan-Wei Chiu <[email protected]>
Reviewed-by: Ian Rogers <[email protected]>
---
include/linux/min_heap.h | 9 +--------
1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/include/linux/min_heap.h b/include/linux/min_heap.h
index f907c694e852..78de60f6ef1c 100644
--- a/include/linux/min_heap.h
+++ b/include/linux/min_heap.h
@@ -190,7 +190,6 @@ bool __min_heap_push(min_heap_char *heap, const void *element, size_t elem_size,
const struct min_heap_callbacks *func, void *args)
{
void *data = heap->data;
- void *child, *parent;
int pos;

if (WARN_ONCE(heap->nr >= heap->size, "Pushing on a full heap"))
@@ -202,13 +201,7 @@ bool __min_heap_push(min_heap_char *heap, const void *element, size_t elem_size,
heap->nr++;

/* Sift child at pos up. */
- for (; pos > 0; pos = (pos - 1) / 2) {
- child = data + (pos * elem_size);
- parent = data + ((pos - 1) / 2) * elem_size;
- if (func->less(parent, child, args))
- break;
- func->swp(parent, child, args);
- }
+ __min_heap_sift_up(heap, elem_size, pos, func, args);

return true;
}
--
2.34.1


2024-04-25 21:04:16

by Kent Overstreet

[permalink] [raw]
Subject: Re: [PATCH v4 00/16] treewide: Refactor heap related implementation

Hey Stephen, I think this is ready for -next.

https://github.com/visitorckw/linux.git refactor-heap-v4

Kuan, please add my acked-by to the bcachefs patch as well.

Cheers,
Kent

On Thu, Apr 25, 2024 at 10:18:10PM +0800, Kuan-Wei Chiu wrote:
> This patch series focuses on several adjustments related to heap
> implementation. Firstly, a type-safe interface has been added to the
> min_heap, along with the introduction of several new functions to
> enhance its functionality. Additionally, the heap implementation for
> bcache and bcachefs has been replaced with the generic min_heap
> implementation from include/linux. Furthermore, several typos have been
> corrected.
>
> Previous discussion with Kent Overstreet:
> https://lkml.kernel.org/ioyfizrzq7w7mjrqcadtzsfgpuntowtjdw5pgn4qhvsdp4mqqg@nrlek5vmisbu
>
> Regards,
> Kuan-Wei
>
> ---
>
> You can preview this patch series on the 'refactor-heap-v4' branch of
> the repository at the following link:
>
> https://github.com/visitorckw/linux.git
>
> Changes in v4:
> - Change struct initializations to use designated initializers.
> - Replace memcpy() with func->swp() in heap_del() due to issues with
> set_backpointer in bcachefs when setting idx.
> - Fix an error in ec_stripes_heap_swap() where
> ec_stripes_heap_set_backpointer() should be called after swapping.
>
> Changes in v3:
> - Avoid heap->heap.nr to eliminate the nested types.
> - Add MIN_HEAP_PREALLOCATED macro for preallocating some elements.
> - Use min_heap_sift_up() in min_heap_push().
> - Fix a bug in heap_del() where we should copy the last element to
> 'data + idx * element_size' instead of 'data'.
> - Add testcases for heap_del().
> - Fix bugs in bcache/bcachefs patches where the parameter types in
> some compare functions should have been 'type **', but were
> mistakenly written as 'type *'.
>
> 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().
> - Update lib/test_min_heap.c to use min_heap_init().
> - Refine the commit message for bcache and bcachefs.
> - Adjust the order of patches in the patch series.
>
> Link to v3: https://lore.kernel.org/[email protected]
> Link to v2: https://lore.kernel.org/[email protected]
> Link to v1: https://lkml.kernel.org/[email protected]
>
> Kuan-Wei Chiu (16):
> perf/core: Fix several typos
> bcache: Fix typo
> bcachefs: Fix typo
> lib min_heap: Add type safe interface
> lib min_heap: Add min_heap_init()
> lib min_heap: Add min_heap_peek()
> lib min_heap: Add min_heap_full()
> lib min_heap: Add args for min_heap_callbacks
> lib min_heap: Add min_heap_sift_up()
> lib min_heap: Add min_heap_del()
> lib min_heap: Update min_heap_push() and min_heap_pop() to return bool
> values
> lib min_heap: Rename min_heapify() to min_heap_sift_down()
> lib min_heap: Update min_heap_push() to use min_heap_sift_up()
> lib/test_min_heap: Add test for heap_del()
> bcache: Remove heap-related macros and switch to generic min_heap
> bcachefs: Remove heap-related macros and switch to generic min_heap
>
> 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.c | 2 +-
> drivers/md/bcache/util.h | 67 +-----------
> drivers/md/bcache/writeback.c | 3 +
> drivers/md/dm-vdo/repair.c | 19 ++--
> drivers/md/dm-vdo/slab-depot.c | 14 +--
> fs/bcachefs/clock.c | 43 ++++++--
> fs/bcachefs/clock_types.h | 2 +-
> fs/bcachefs/ec.c | 76 ++++++++-----
> fs/bcachefs/ec_types.h | 2 +-
> fs/bcachefs/util.c | 2 +-
> fs/bcachefs/util.h | 118 +--------------------
> include/linux/min_heap.h | 188 +++++++++++++++++++++++++--------
> kernel/events/core.c | 29 ++---
> lib/test_min_heap.c | 75 +++++++++----
> 22 files changed, 522 insertions(+), 395 deletions(-)
>
> --
> 2.34.1
>

2024-04-26 00:14:46

by Kuan-Wei Chiu

[permalink] [raw]
Subject: Re: [PATCH v4 00/16] treewide: Refactor heap related implementation

On Thu, Apr 25, 2024 at 04:54:54PM -0400, Kent Overstreet wrote:
> Hey Stephen, I think this is ready for -next.
>
> https://github.com/visitorckw/linux.git refactor-heap-v4
>
> Kuan, please add my acked-by to the bcachefs patch as well.
>
Acked-by tag has been added to the repository mentioned above and
pushed out.

Regards,
Kuan-Wei
>
> On Thu, Apr 25, 2024 at 10:18:10PM +0800, Kuan-Wei Chiu wrote:
> > This patch series focuses on several adjustments related to heap
> > implementation. Firstly, a type-safe interface has been added to the
> > min_heap, along with the introduction of several new functions to
> > enhance its functionality. Additionally, the heap implementation for
> > bcache and bcachefs has been replaced with the generic min_heap
> > implementation from include/linux. Furthermore, several typos have been
> > corrected.
> >
> > Previous discussion with Kent Overstreet:
> > https://lkml.kernel.org/ioyfizrzq7w7mjrqcadtzsfgpuntowtjdw5pgn4qhvsdp4mqqg@nrlek5vmisbu
> >
> > Regards,
> > Kuan-Wei
> >
> > ---
> >
> > You can preview this patch series on the 'refactor-heap-v4' branch of
> > the repository at the following link:
> >
> > https://github.com/visitorckw/linux.git
> >
> > Changes in v4:
> > - Change struct initializations to use designated initializers.
> > - Replace memcpy() with func->swp() in heap_del() due to issues with
> > set_backpointer in bcachefs when setting idx.
> > - Fix an error in ec_stripes_heap_swap() where
> > ec_stripes_heap_set_backpointer() should be called after swapping.
> >
> > Changes in v3:
> > - Avoid heap->heap.nr to eliminate the nested types.
> > - Add MIN_HEAP_PREALLOCATED macro for preallocating some elements.
> > - Use min_heap_sift_up() in min_heap_push().
> > - Fix a bug in heap_del() where we should copy the last element to
> > 'data + idx * element_size' instead of 'data'.
> > - Add testcases for heap_del().
> > - Fix bugs in bcache/bcachefs patches where the parameter types in
> > some compare functions should have been 'type **', but were
> > mistakenly written as 'type *'.
> >
> > 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().
> > - Update lib/test_min_heap.c to use min_heap_init().
> > - Refine the commit message for bcache and bcachefs.
> > - Adjust the order of patches in the patch series.
> >
> > Link to v3: https://lore.kernel.org/[email protected]
> > Link to v2: https://lore.kernel.org/[email protected]
> > Link to v1: https://lkml.kernel.org/[email protected]
> >
> > Kuan-Wei Chiu (16):
> > perf/core: Fix several typos
> > bcache: Fix typo
> > bcachefs: Fix typo
> > lib min_heap: Add type safe interface
> > lib min_heap: Add min_heap_init()
> > lib min_heap: Add min_heap_peek()
> > lib min_heap: Add min_heap_full()
> > lib min_heap: Add args for min_heap_callbacks
> > lib min_heap: Add min_heap_sift_up()
> > lib min_heap: Add min_heap_del()
> > lib min_heap: Update min_heap_push() and min_heap_pop() to return bool
> > values
> > lib min_heap: Rename min_heapify() to min_heap_sift_down()
> > lib min_heap: Update min_heap_push() to use min_heap_sift_up()
> > lib/test_min_heap: Add test for heap_del()
> > bcache: Remove heap-related macros and switch to generic min_heap
> > bcachefs: Remove heap-related macros and switch to generic min_heap
> >
> > 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.c | 2 +-
> > drivers/md/bcache/util.h | 67 +-----------
> > drivers/md/bcache/writeback.c | 3 +
> > drivers/md/dm-vdo/repair.c | 19 ++--
> > drivers/md/dm-vdo/slab-depot.c | 14 +--
> > fs/bcachefs/clock.c | 43 ++++++--
> > fs/bcachefs/clock_types.h | 2 +-
> > fs/bcachefs/ec.c | 76 ++++++++-----
> > fs/bcachefs/ec_types.h | 2 +-
> > fs/bcachefs/util.c | 2 +-
> > fs/bcachefs/util.h | 118 +--------------------
> > include/linux/min_heap.h | 188 +++++++++++++++++++++++++--------
> > kernel/events/core.c | 29 ++---
> > lib/test_min_heap.c | 75 +++++++++----
> > 22 files changed, 522 insertions(+), 395 deletions(-)
> >
> > --
> > 2.34.1
> >