[PATCH 6/8] lib min_heap: add eqaware variant of min_heap_del()
Kuan-Wei Chiu <[email protected]>
| Newsgroups | org.kernel.vger.linux-bcache,org.kernel.vger.linux-doc,org.kernel.vger.linux-kernel,org.kernel.vger.stable |
|---|---|
| Message-ID | <[email protected]> |
Introduce min_heap_del_eqaware() as a variant of min_heap_del() that uses the equality-aware version of sift_down, which is implemented in a top-down manner. This top-down sift_down reduces the number of comparisons from O(log2(n)) to O(1) in cases where many elements have equal priority. It enables more efficient heap construction when the heap contains a large number of equal elements. Cc: [email protected] # 6.11+ Signed-off-by: Kuan-Wei Chiu <[email protected]> --- include/linux/min_heap.h | 19 ++++++++++++++----- lib/min_heap.c | 4 ++-- 2 files changed, 16 insertions(+), 7 deletions(-) diff --git a/include/linux/min_heap.h b/include/linux/min_heap.h index d7bf8dd0f6b1..f34df8dd2e17 100644 --- a/include/linux/min_heap.h +++ b/include/linux/min_heap.h @@ -470,10 +470,12 @@ 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, bool eqaware) { void *data = heap->data; void (*swp)(void *lhs, void *rhs, void *args) = func->swp; + siftdown_fn_t sift_down = eqaware ? __min_heap_sift_down_eqaware_inline : + __min_heap_sift_down_inline; if (WARN_ONCE(heap->nr <= 0, "Popping an empty heap")) return false; @@ -487,14 +489,18 @@ 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, false) + +#define min_heap_del_eqaware_inline(_heap, _idx, _func, _args) \ + __min_heap_del_inline(container_of(&(_heap)->nr, min_heap_char, nr), \ + __minheap_obj_size(_heap), _idx, _func, _args, true) void __min_heap_init(min_heap_char *heap, void *data, size_t size); void *__min_heap_peek(struct min_heap_char *heap); @@ -514,7 +520,7 @@ void __min_heap_pop_push(min_heap_char *heap, const void *element, size_t elem_s 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, bool eqaware); #define min_heap_init(_heap, _data, _size) \ __min_heap_init(container_of(&(_heap)->nr, min_heap_char, nr), _data, _size) @@ -554,6 +560,9 @@ bool __min_heap_del(min_heap_char *heap, size_t elem_size, size_t idx, __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, false) +#define min_heap_del_eqaware(_heap, _idx, _func, _args) \ + __min_heap_del(container_of(&(_heap)->nr, min_heap_char, nr), \ + __minheap_obj_size(_heap), _idx, _func, _args, true) #endif /* _LINUX_MIN_HEAP_H */ diff --git a/lib/min_heap.c b/lib/min_heap.c index a69d8b80d443..50f224f174d5 100644 --- a/lib/min_heap.c +++ b/lib/min_heap.c @@ -70,8 +70,8 @@ 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, bool eqaware) { - return __min_heap_del_inline(heap, elem_size, idx, func, args); + return __min_heap_del_inline(heap, elem_size, idx, func, args, eqaware); } EXPORT_SYMBOL(__min_heap_del); -- 2.34.1