[PATCH 3/8] lib min_heap: add eqaware variant of min_heapify_all()
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_heapify_all_eqaware() as a variant of min_heapify_all() 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 4cd8fd9db259..c2f6e1450505 100644 --- a/include/linux/min_heap.h +++ b/include/linux/min_heap.h @@ -371,17 +371,23 @@ 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, bool eqaware) { ssize_t i; + siftdown_fn_t sift_down = eqaware ? __min_heap_sift_down_eqaware_inline : + __min_heap_sift_down_inline; 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, false) + +#define min_heapify_all_eqaware_inline(_heap, _func, _args) \ + __min_heapify_all_inline(container_of(&(_heap)->nr, min_heap_char, nr), \ + __minheap_obj_size(_heap), _func, _args, true) /* Remove minimum element from the heap, O(log2(nr)). */ static __always_inline @@ -487,7 +493,7 @@ void __min_heap_sift_down_eqaware(min_heap_char *heap, size_t pos, size_t elem_s 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, bool eqaware); bool __min_heap_pop(min_heap_char *heap, 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, @@ -514,7 +520,10 @@ 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, false) +#define min_heapify_all_eqaware(_heap, _func, _args) \ + __min_heapify_all(container_of(&(_heap)->nr, min_heap_char, nr), \ + __minheap_obj_size(_heap), _func, _args, true) #define min_heap_pop(_heap, _func, _args) \ __min_heap_pop(container_of(&(_heap)->nr, min_heap_char, nr), \ __minheap_obj_size(_heap), _func, _args) diff --git a/lib/min_heap.c b/lib/min_heap.c index 2225f40d0d7a..a422cfaff196 100644 --- a/lib/min_heap.c +++ b/lib/min_heap.c @@ -42,9 +42,9 @@ 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, bool eqaware) { - __min_heapify_all_inline(heap, elem_size, func, args); + __min_heapify_all_inline(heap, elem_size, func, args, eqaware); } EXPORT_SYMBOL(__min_heapify_all); -- 2.34.1