[PATCH v2 10/15] lib min_heap: Add args for min_heap_callbacks

From: Kuan-Wei Chiu
Date: Wed Mar 20 2024 - 10:57:43 EST

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 <visitorckw@xxxxxxxxx>
---
Changes in v2:
- Add attribute __always_unused to the compare and swap functions that
do not use the args parameter.

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 7663fa2098f4..6acaebcd305d 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->heap.nr];
- swap_mappings(heap->heap.data, last);
- min_heapify(heap, 0, &repair_min_heap);
+ swap_mappings(heap->heap.data, last, NULL);
+ min_heapify(heap, 0, &repair_min_heap, NULL);
return last;
}

@@ -1121,7 +1121,7 @@ static void recover_block_map(struct vdo_completion *completion)
repair->replay_heap.heap.data = repair->entries;
repair->replay_heap.heap.nr = repair->block_map_entry_count;
repair->replay_heap.heap.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 3309480170c3..102f492bb1f8 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;
@@ -3523,7 +3524,7 @@ static int __must_check vdo_prepare_slabs_for_allocation(struct block_allocator
heap.heap.data = slab_statuses;
heap.heap.nr = allocator->slab_count;
heap.heap.size = allocator->slab_count;
- min_heapify_all(&heap, &slab_status_min_heap);
+ min_heapify_all(&heap, &slab_status_min_heap, NULL);

while (heap.heap.nr > 0) {
bool high_priority;
@@ -3531,7 +3532,7 @@ 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 af12531474a4..879a9d12e030 100644
--- a/include/linux/min_heap.h
+++ b/include/linux/min_heap.h
@@ -40,8 +40,8 @@ struct _name { \
* @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. */
@@ -79,7 +79,7 @@ bool __min_heap_full(struct __min_heap *heap)
/* Sift the element at pos down the heap. */
static __always_inline
void __min_heapify(struct __min_heap *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;
@@ -92,7 +92,7 @@ void __min_heapify(struct __min_heap *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. */
@@ -100,38 +100,38 @@ void __min_heapify(struct __min_heap *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(&(_heap)->heap, _pos, __minheap_obj_size(_heap), _func)
+#define min_heapify(_heap, _pos, _func, _args) \
+ __min_heapify(&(_heap)->heap, _pos, __minheap_obj_size(_heap), _func, _args)

/* Floyd's approach to heapification that is O(nr). */
static __always_inline
void __min_heapify_all(struct __min_heap *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(&(_heap)->heap, __minheap_obj_size(_heap), _func)
+#define min_heapify_all(_heap, _func, _args) \
+ __min_heapify_all(&(_heap)->heap, __minheap_obj_size(_heap), _func, _args)

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

@@ -141,11 +141,11 @@ void __min_heap_pop(struct __min_heap *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(&(_heap)->heap, __minheap_obj_size(_heap), _func)
+#define min_heap_pop(_heap, _func, _args) \
+ __min_heap_pop(&(_heap)->heap, __minheap_obj_size(_heap), _func, _args)

/*
* Remove the minimum element and then push the given element. The
@@ -155,19 +155,20 @@ void __min_heap_pop(struct __min_heap *heap, size_t elem_size,
static __always_inline
void __min_heap_pop_push(struct __min_heap *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(&(_heap)->heap, _element, __minheap_obj_size(_heap), _func)
+#define min_heap_pop_push(_heap, _element, _func, _args) \
+ __min_heap_pop_push(&(_heap)->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(struct __min_heap *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;
@@ -185,14 +186,14 @@ void __min_heap_push(struct __min_heap *heap, const void *element, size_t elem_s
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(&(_heap)->heap, _element, __minheap_obj_size(_heap), _func)
+#define min_heap_push(_heap, _element, _func, _args) \
+ __min_heap_push(&(_heap)->heap, _element, __minheap_obj_size(_heap), _func, _args)

/* Sift up ith element from the heap, O(log2(nr)). */
static __always_inline
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 065dfaa8b009..c32a78c489f3 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;

@@ -3779,7 +3779,7 @@ 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.heap.nr) {
ret = func(*evt, data);
@@ -3788,9 +3788,9 @@ 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 af2e446034d8..062e908e9fa3 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->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.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.heap.nr < heap.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.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