[PATCH 5/8] lib min_heap: add eqaware variant of min_heap_pop_push()
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_pop_push_eqaware() as a variant of min_heap_pop_push() 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 | 20 +++++++++++++++----- lib/min_heap.c | 4 ++-- 2 files changed, 17 insertions(+), 7 deletions(-) diff --git a/include/linux/min_heap.h b/include/linux/min_heap.h index 6c45d617b027..d7bf8dd0f6b1 100644 --- a/include/linux/min_heap.h +++ b/include/linux/min_heap.h @@ -424,15 +424,22 @@ 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, bool eqaware) { + siftdown_fn_t sift_down = eqaware ? __min_heap_sift_down_eqaware_inline : + __min_heap_sift_down_inline; + 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, false) + +#define min_heap_pop_push_eqaware_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, true) /* Push an element on to the heap, O(log2(nr)). */ static __always_inline @@ -503,7 +510,7 @@ void __min_heapify_all(min_heap_char *heap, size_t elem_size, bool __min_heap_pop(min_heap_char *heap, size_t elem_size, const struct min_heap_callbacks *func, void *args, bool eqaware); 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, bool eqaware); 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, @@ -538,7 +545,10 @@ bool __min_heap_del(min_heap_char *heap, size_t elem_size, size_t idx, __minheap_obj_size(_heap), _func, _args, true) #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, false) +#define min_heap_pop_push_eqaware(_heap, _element, _func, _args) \ + __min_heap_pop_push(container_of(&(_heap)->nr, min_heap_char, nr), _element, \ + __minheap_obj_size(_heap), _func, _args, true) #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) diff --git a/lib/min_heap.c b/lib/min_heap.c index dae3ed39421a..a69d8b80d443 100644 --- a/lib/min_heap.c +++ b/lib/min_heap.c @@ -56,9 +56,9 @@ bool __min_heap_pop(min_heap_char *heap, size_t elem_size, 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, bool eqaware) { - __min_heap_pop_push_inline(heap, element, elem_size, func, args); + __min_heap_pop_push_inline(heap, element, elem_size, func, args, eqaware); } EXPORT_SYMBOL(__min_heap_pop_push); -- 2.34.1