lib/test_min_heap: add test for heap_del()

Add test cases for the min_heap_del() to ensure its functionality is
thoroughly tested.

Link: https://lkml.kernel.org/r/20240524152958.919343-15-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>
diff --git a/lib/test_min_heap.c b/lib/test_min_heap.c
index f59638c..9e1feb9 100644
--- a/lib/test_min_heap.c
+++ b/lib/test_min_heap.c
@@ -165,6 +165,40 @@ static __init int test_heap_pop_push(bool min_heap)
 	return err;
 }
 
+static __init int test_heap_del(bool min_heap)
+{
+	int values[] = { 3, 1, 2, 4, 0x8000000, 0x7FFFFFF, 0,
+			 -3, -1, -2, -4, 0x8000000, 0x7FFFFFF };
+	struct min_heap_test heap;
+
+	min_heap_init(&heap, values, ARRAY_SIZE(values));
+	heap.nr = ARRAY_SIZE(values);
+	struct min_heap_callbacks funcs = {
+		.less = min_heap ? less_than : greater_than,
+		.swp = swap_ints,
+	};
+	int i, err;
+
+	/* Test with known set of values. */
+	min_heapify_all(&heap, &funcs, NULL);
+	for (i = 0; i < ARRAY_SIZE(values) / 2; i++)
+		min_heap_del(&heap, get_random_u32() % heap.nr, &funcs, NULL);
+	err = pop_verify_heap(min_heap, &heap, &funcs);
+
+
+	/* Test with randomly generated values. */
+	heap.nr = ARRAY_SIZE(values);
+	for (i = 0; i < heap.nr; i++)
+		values[i] = get_random_u32();
+	min_heapify_all(&heap, &funcs, NULL);
+
+	for (i = 0; i < ARRAY_SIZE(values) / 2; i++)
+		min_heap_del(&heap, get_random_u32() % heap.nr, &funcs, NULL);
+	err += pop_verify_heap(min_heap, &heap, &funcs);
+
+	return err;
+}
+
 static int __init test_min_heap_init(void)
 {
 	int err = 0;
@@ -175,6 +209,8 @@ static int __init test_min_heap_init(void)
 	err += test_heap_push(false);
 	err += test_heap_pop_push(true);
 	err += test_heap_pop_push(false);
+	err += test_heap_del(true);
+	err += test_heap_del(false);
 	if (err) {
 		pr_err("test failed with %d errors\n", err);
 		return -EINVAL;