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authorKuan-Wei Chiu <visitorckw@gmail.com>2024-05-24 23:29:51 +0800
committerAndrew Morton <akpm@linux-foundation.org>2024-06-24 22:24:58 -0700
commiteaa0bc7119247942200b9209d40ffd86ace347d4 (patch)
treef095cf17c91025cc101e948e97790aa145c60935
parent267607e87599509a6a39a5f7dd3959365e58af27 (diff)
lib min_heap: add min_heap_sift_up()
Add min_heap_sift_up() to sift up the element at index 'idx' in the heap. Link: https://lkml.kernel.org/r/20240524152958.919343-10-visitorckw@gmail.com Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com> Reviewed-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Brian Foster <bfoster@redhat.com> Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw> Cc: Coly Li <colyli@suse.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Sakai <msakai@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--include/linux/min_heap.h20
1 files changed, 20 insertions, 0 deletions
diff --git a/include/linux/min_heap.h b/include/linux/min_heap.h
index 4acd0f4b3fafb..ddd0186afb774 100644
--- a/include/linux/min_heap.h
+++ b/include/linux/min_heap.h
@@ -111,6 +111,26 @@ void __min_heapify(min_heap_char *heap, int pos, size_t elem_size,
#define min_heapify(_heap, _pos, _func, _args) \
__min_heapify((min_heap_char *)_heap, _pos, __minheap_obj_size(_heap), _func, _args)
+/* Sift up ith element from the heap, O(log2(nr)). */
+static __always_inline
+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 *data = heap->data;
+ size_t parent;
+
+ while (idx) {
+ parent = (idx - 1) / 2;
+ if (func->less(data + parent * elem_size, data + idx * elem_size, args))
+ break;
+ func->swp(data + parent * elem_size, data + idx * elem_size, args);
+ idx = parent;
+ }
+}
+
+#define min_heap_sift_up(_heap, _idx, _func, _args) \
+ __min_heap_sift_up((min_heap_char *)_heap, __minheap_obj_size(_heap), _idx, _func, _args)
+
/* Floyd's approach to heapification that is O(nr). */
static __always_inline
void __min_heapify_all(min_heap_char *heap, size_t elem_size,