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 <visitorckw@xxxxxxxxx> Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx> --- 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
