diff --git a/tests/kernel/smp/src/main.c b/tests/kernel/smp/src/main.c
index 13b80123a894d..990d56ebc18a3 100644
--- a/tests/kernel/smp/src/main.c
+++ b/tests/kernel/smp/src/main.c
@@ -14,12 +14,22 @@
 #error SMP test requires at least two CPUs!
 #endif
 
+/*
+ * The test is designed to work with no more than 12 CPUs.
+ * If attempting to run on a platform with more than that,
+ * create a custom board overlay file to reduce the number
+ * of CPUs to 12.
+ */
+#if CONFIG_MP_MAX_NUM_CPUS > 12
+#error "Test only supports up to 12 CPUs\nReduce CONFIG_MP_MAX_NUM_CPUS\n"
+#endif
+
 #define RUN_FACTOR (CONFIG_SMP_TEST_RUN_FACTOR / 100.0)
 
 #define T2_STACK_SIZE (2048 + CONFIG_TEST_EXTRA_STACK_SIZE)
 #define STACK_SIZE (384 + CONFIG_TEST_EXTRA_STACK_SIZE)
 #define DELAY_US 50000
-#define TIMEOUT 1000
+#define TIMEOUT 5000
 #define EQUAL_PRIORITY 1
 #define TIME_SLICE_MS 500
 #define THREAD_DELAY 1
@@ -372,11 +382,11 @@ ZTEST(smp, test_coop_resched_threads)
 	 * since we don't give up current CPU, last thread
 	 * will not get scheduled
 	 */
-	spawn_threads(K_PRIO_COOP(10), num_threads, !EQUAL_PRIORITY,
+	spawn_threads(K_PRIO_COOP(12), num_threads, !EQUAL_PRIORITY,
 		      &thread_entry_fn, THREAD_DELAY);
 
 	/* Wait for some time to let other core's thread run */
-	k_busy_wait(DELAY_US);
+	k_busy_wait(DELAY_US * 5);
 
 
 	/* Reassure that cooperative thread's are not preempted
@@ -413,7 +423,7 @@ ZTEST(smp, test_preempt_resched_threads)
 	 * lower priority thread should
 	 * be preempted by higher ones
 	 */
-	spawn_threads(K_PRIO_PREEMPT(10), num_threads, !EQUAL_PRIORITY,
+	spawn_threads(K_PRIO_PREEMPT(12), num_threads, !EQUAL_PRIORITY,
 		      &thread_entry_fn, THREAD_DELAY);
 
 	spin_for_threads_exit();
@@ -446,11 +456,11 @@ ZTEST(smp, test_yield_threads)
 	 * of cores, so the last thread would be
 	 * pending.
 	 */
-	spawn_threads(K_PRIO_COOP(10), num_threads, !EQUAL_PRIORITY,
+	spawn_threads(K_PRIO_COOP(12), num_threads, !EQUAL_PRIORITY,
 		      &thread_entry_fn, !THREAD_DELAY);
 
 	k_yield();
-	k_busy_wait(DELAY_US);
+	k_busy_wait(DELAY_US * 5);
 
 	for (int i = 0; i < num_threads; i++) {
 		zassert_true(tinfo[i].executed == 1,
@@ -475,7 +485,7 @@ ZTEST(smp, test_sleep_threads)
 {
 	unsigned int num_threads = arch_num_cpus();
 
-	spawn_threads(K_PRIO_COOP(10), num_threads, !EQUAL_PRIORITY,
+	spawn_threads(K_PRIO_COOP(12), num_threads, !EQUAL_PRIORITY,
 		      &thread_entry_fn, !THREAD_DELAY);
 
 	k_msleep(TIMEOUT);
@@ -533,7 +543,7 @@ static void check_wokeup_threads(int tnum)
 	/* k_wakeup() isn't synchronous, give the other CPU time to
 	 * schedule them
 	 */
-	k_busy_wait(200000);
+	k_busy_wait(300000);
 
 	for (i = 0; i < tnum; i++) {
 		if (tinfo[i].executed == 1 && threads_woke_up <= tnum) {
@@ -558,7 +568,7 @@ ZTEST(smp, test_wakeup_threads)
 	unsigned int num_threads = arch_num_cpus();
 
 	/* Spawn threads to run on all remaining cores */
-	spawn_threads(K_PRIO_COOP(10), num_threads - 1, !EQUAL_PRIORITY,
+	spawn_threads(K_PRIO_COOP(12), num_threads - 1, !EQUAL_PRIORITY,
 		      &thread_wakeup_entry, !THREAD_DELAY);
 
 	/* Check if all the threads have started, then call wakeup */