[PATCH 1/3] lib min_heap: refactor min_heap to allow the alternative sift-down function to be used
Robert Pang <[email protected]>
| Newsgroups | org.kernel.vger.linux-bcache |
|---|---|
| Message-ID | <[email protected]> |
Refactor these min_heap's internal functions that require sifting down elements to take the sift-down function to use. This change will allow for the use of alternative sift-down strategies, potentially offering significant performance improvements for certain data distributions compared to the current bottom-up approach. - heapify_all - heap_pop - heap_pop_push - heap_del Signed-off-by: Robert Pang <[email protected]> --- include/linux/min_heap.h | 60 ++++++++++++++++++++++++++-------------- lib/min_heap.c | 24 ++++++++++------ 2 files changed, 56 insertions(+), 28 deletions(-) diff --git a/include/linux/min_heap.h b/include/linux/min_heap.h index 1160bed6579e..1fe6772170e7 100644 --- a/include/linux/min_heap.h +++ b/include/linux/min_heap.h @@ -322,22 +322,27 @@ void __min_heap_sift_up_inline(min_heap_char *heap, size_t elem_size, size_t idx /* Floyd's approach to heapification that is O(nr). */ static __always_inline void __min_heapify_all_inline(min_heap_char *heap, size_t elem_size, - const struct min_heap_callbacks *func, void *args) + const struct min_heap_callbacks *func, void *args, + void (*sift_down)(min_heap_char *heap, int pos, size_t elem_size, + const struct min_heap_callbacks *func, void *args)) { int i; for (i = heap->nr / 2 - 1; i >= 0; i--) - __min_heap_sift_down_inline(heap, i, elem_size, func, args); + sift_down(heap, i, elem_size, func, args); } #define min_heapify_all_inline(_heap, _func, _args) \ __min_heapify_all_inline(container_of(&(_heap)->nr, min_heap_char, nr), \ - __minheap_obj_size(_heap), _func, _args) + __minheap_obj_size(_heap), _func, _args, \ + __min_heap_sift_down_inline) /* Remove minimum element from the heap, O(log2(nr)). */ static __always_inline bool __min_heap_pop_inline(min_heap_char *heap, size_t elem_size, - const struct min_heap_callbacks *func, void *args) + const struct min_heap_callbacks *func, void *args, + void (*sift_down)(min_heap_char *heap, int pos, size_t elem_size, + const struct min_heap_callbacks *func, void *args)) { void *data = heap->data; @@ -347,14 +352,15 @@ bool __min_heap_pop_inline(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_heap_sift_down_inline(heap, 0, elem_size, func, args); + sift_down(heap, 0, elem_size, func, args); return true; } #define min_heap_pop_inline(_heap, _func, _args) \ __min_heap_pop_inline(container_of(&(_heap)->nr, min_heap_char, nr), \ - __minheap_obj_size(_heap), _func, _args) + __minheap_obj_size(_heap), _func, _args, \ + __min_heap_sift_down_inline) /* * Remove the minimum element and then push the given element. The @@ -363,15 +369,18 @@ bool __min_heap_pop_inline(min_heap_char *heap, size_t elem_size, */ static __always_inline void __min_heap_pop_push_inline(min_heap_char *heap, const void *element, size_t elem_size, - const struct min_heap_callbacks *func, void *args) + const struct min_heap_callbacks *func, void *args, + void (*sift_down)(min_heap_char *heap, int pos, size_t elem_size, + const struct min_heap_callbacks *func, void *args)) { memcpy(heap->data, element, elem_size); - __min_heap_sift_down_inline(heap, 0, elem_size, func, args); + sift_down(heap, 0, elem_size, func, args); } #define min_heap_pop_push_inline(_heap, _element, _func, _args) \ __min_heap_pop_push_inline(container_of(&(_heap)->nr, min_heap_char, nr), _element, \ - __minheap_obj_size(_heap), _func, _args) + __minheap_obj_size(_heap), _func, _args, \ + __min_heap_sift_down_inline) /* Push an element on to the heap, O(log2(nr)). */ static __always_inline @@ -402,7 +411,9 @@ bool __min_heap_push_inline(min_heap_char *heap, const void *element, size_t ele /* Remove ith element from the heap, O(log2(nr)). */ static __always_inline bool __min_heap_del_inline(min_heap_char *heap, size_t elem_size, size_t idx, - const struct min_heap_callbacks *func, void *args) + const struct min_heap_callbacks *func, void *args, + void (*sift_down)(min_heap_char *heap, int pos, size_t elem_size, + const struct min_heap_callbacks *func, void *args)) { void *data = heap->data; void (*swp)(void *lhs, void *rhs, void *args) = func->swp; @@ -419,14 +430,15 @@ bool __min_heap_del_inline(min_heap_char *heap, size_t elem_size, size_t idx, return true; do_swap(data + (idx * elem_size), data + (heap->nr * elem_size), elem_size, swp, args); __min_heap_sift_up_inline(heap, elem_size, idx, func, args); - __min_heap_sift_down_inline(heap, idx, elem_size, func, args); + sift_down(heap, idx, elem_size, func, args); return true; } #define min_heap_del_inline(_heap, _idx, _func, _args) \ __min_heap_del_inline(container_of(&(_heap)->nr, min_heap_char, nr), \ - __minheap_obj_size(_heap), _idx, _func, _args) + __minheap_obj_size(_heap), _idx, _func, _args, \ + __min_heap_sift_down_inline)) void __min_heap_init(min_heap_char *heap, void *data, int size); void *__min_heap_peek(struct min_heap_char *heap); @@ -436,15 +448,23 @@ void __min_heap_sift_down(min_heap_char *heap, int pos, size_t elem_size, 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 __min_heapify_all(min_heap_char *heap, size_t elem_size, - const struct min_heap_callbacks *func, void *args); + const struct min_heap_callbacks *func, void *args, + void (*sift_down)(min_heap_char *heap, int pos, size_t elem_size, + const struct min_heap_callbacks *func, void *args)); bool __min_heap_pop(min_heap_char *heap, size_t elem_size, - const struct min_heap_callbacks *func, void *args); + const struct min_heap_callbacks *func, void *args, + void (*sift_down)(min_heap_char *heap, int pos, size_t elem_size, + const struct min_heap_callbacks *func, void *args)); void __min_heap_pop_push(min_heap_char *heap, const void *element, size_t elem_size, - const struct min_heap_callbacks *func, void *args); + const struct min_heap_callbacks *func, void *args, + void (*sift_down)(min_heap_char *heap, int pos, size_t elem_size, + const struct min_heap_callbacks *func, void *args)); bool __min_heap_push(min_heap_char *heap, const void *element, size_t elem_size, const struct min_heap_callbacks *func, void *args); bool __min_heap_del(min_heap_char *heap, size_t elem_size, size_t idx, - const struct min_heap_callbacks *func, void *args); + const struct min_heap_callbacks *func, void *args, + void (*sift_down)(min_heap_char *heap, int pos, size_t elem_size, + const struct min_heap_callbacks *func, void *args)); #define min_heap_init(_heap, _data, _size) \ __min_heap_init(container_of(&(_heap)->nr, min_heap_char, nr), _data, _size) @@ -460,18 +480,18 @@ bool __min_heap_del(min_heap_char *heap, size_t elem_size, size_t idx, __minheap_obj_size(_heap), _idx, _func, _args) #define min_heapify_all(_heap, _func, _args) \ __min_heapify_all(container_of(&(_heap)->nr, min_heap_char, nr), \ - __minheap_obj_size(_heap), _func, _args) + __minheap_obj_size(_heap), _func, _args, __min_heap_sift_down) #define min_heap_pop(_heap, _func, _args) \ __min_heap_pop(container_of(&(_heap)->nr, min_heap_char, nr), \ - __minheap_obj_size(_heap), _func, _args) + __minheap_obj_size(_heap), _func, _args, __min_heap_sift_down) #define min_heap_pop_push(_heap, _element, _func, _args) \ __min_heap_pop_push(container_of(&(_heap)->nr, min_heap_char, nr), _element, \ - __minheap_obj_size(_heap), _func, _args) + __minheap_obj_size(_heap), _func, _args, __min_heap_sift_down) #define min_heap_push(_heap, _element, _func, _args) \ __min_heap_push(container_of(&(_heap)->nr, min_heap_char, nr), _element, \ __minheap_obj_size(_heap), _func, _args) #define min_heap_del(_heap, _idx, _func, _args) \ __min_heap_del(container_of(&(_heap)->nr, min_heap_char, nr), \ - __minheap_obj_size(_heap), _idx, _func, _args) + __minheap_obj_size(_heap), _idx, _func, _args, __min_heap_sift_down) #endif /* _LINUX_MIN_HEAP_H */ diff --git a/lib/min_heap.c b/lib/min_heap.c index 4485372ff3b1..4ec425788783 100644 --- a/lib/min_heap.c +++ b/lib/min_heap.c @@ -35,23 +35,29 @@ void __min_heap_sift_up(min_heap_char *heap, size_t elem_size, size_t idx, EXPORT_SYMBOL(__min_heap_sift_up); void __min_heapify_all(min_heap_char *heap, size_t elem_size, - const struct min_heap_callbacks *func, void *args) + const struct min_heap_callbacks *func, void *args, + void (*sift_down)(min_heap_char *heap, int pos, size_t elem_size, + const struct min_heap_callbacks *func, void *args)) { - __min_heapify_all_inline(heap, elem_size, func, args); + __min_heapify_all_inline(heap, elem_size, func, args, sift_down); } EXPORT_SYMBOL(__min_heapify_all); bool __min_heap_pop(min_heap_char *heap, size_t elem_size, - const struct min_heap_callbacks *func, void *args) + const struct min_heap_callbacks *func, void *args, + void (*sift_down)(min_heap_char *heap, int pos, size_t elem_size, + const struct min_heap_callbacks *func, void *args)) { - return __min_heap_pop_inline(heap, elem_size, func, args); + return __min_heap_pop_inline(heap, elem_size, func, args, sift_down); } EXPORT_SYMBOL(__min_heap_pop); void __min_heap_pop_push(min_heap_char *heap, const void *element, size_t elem_size, - const struct min_heap_callbacks *func, void *args) + const struct min_heap_callbacks *func, void *args, + void (*sift_down)(min_heap_char *heap, int pos, size_t elem_size, + const struct min_heap_callbacks *func, void *args)) { - __min_heap_pop_push_inline(heap, element, elem_size, func, args); + __min_heap_pop_push_inline(heap, element, elem_size, func, args, sift_down); } EXPORT_SYMBOL(__min_heap_pop_push); @@ -63,8 +69,10 @@ bool __min_heap_push(min_heap_char *heap, const void *element, size_t elem_size, EXPORT_SYMBOL(__min_heap_push); bool __min_heap_del(min_heap_char *heap, size_t elem_size, size_t idx, - const struct min_heap_callbacks *func, void *args) + const struct min_heap_callbacks *func, void *args, + void (*sift_down)(min_heap_char *heap, int pos, size_t elem_size, + const struct min_heap_callbacks *func, void *args)) { - return __min_heap_del_inline(heap, elem_size, idx, func, args); + return __min_heap_del_inline(heap, elem_size, idx, func, args, sift_down); } EXPORT_SYMBOL(__min_heap_del); -- 2.50.0.rc1.591.g9c95f17f64-goog