diff --git a/arch/arm64/configs/openeuler_defconfig b/arch/arm64/configs/openeuler_defconfig
index 12e4828c9cd147bf58117e727f86a9b773b91a7e..a4928ab384b7a885e8e990edcc32c34142b99c1f 100644
--- a/arch/arm64/configs/openeuler_defconfig
+++ b/arch/arm64/configs/openeuler_defconfig
@@ -7074,6 +7074,7 @@ CONFIG_CMA_ALIGNMENT=8
 CONFIG_DMA_MAP_BENCHMARK=y
 CONFIG_SGL_ALLOC=y
 CONFIG_CHECK_SIGNATURE=y
+# CONFIG_FORCE_NR_CPUS is not set
 CONFIG_CPU_RMAP=y
 CONFIG_DQL=y
 CONFIG_GLOB=y
diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c
index 85f597917c6ff3a457533e1eeeaee9ee2c6cbb9f..5b6408296786cdfbcc242cea51ea4bab543cddb3 100644
--- a/arch/loongarch/kernel/setup.c
+++ b/arch/loongarch/kernel/setup.c
@@ -526,7 +526,7 @@ static void __init prefill_possible_map(void)
 	for (; i < NR_CPUS; i++)
 		set_cpu_possible(i, false);
 
-	nr_cpu_ids = possible;
+	set_nr_cpu_ids(possible);
 }
 #endif
 
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index b7eb7dd96e179d48fd70e1fed7c93ed4ebb9533b..fd5fb8f82898411253df6e359b3b5f7e3faedc05 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -756,7 +756,7 @@ static void __init prefill_possible_map(void)
 	for (; i < NR_CPUS; i++)
 		set_cpu_possible(i, false);
 
-	nr_cpu_ids = possible;
+	set_nr_cpu_ids(possible);
 }
 #else
 static inline void prefill_possible_map(void) {}
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 53def7b7f5ce7fcf24636352546a17d5838255be..bc6d9f8f6bb75ce0e1fa1244f37860b2bed92927 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -398,8 +398,12 @@ generic_secondary_common_init:
 #else
 	LOAD_REG_ADDR(r8, paca_ptrs)	/* Load paca_ptrs pointe	 */
 	ld	r8,0(r8)		/* Get base vaddr of array	 */
+#if (NR_CPUS == 1) || defined(CONFIG_FORCE_NR_CPUS)
+	LOAD_REG_IMMEDIATE(r7, NR_CPUS)
+#else
 	LOAD_REG_ADDR(r7, nr_cpu_ids)	/* Load nr_cpu_ids address       */
 	lwz	r7,0(r7)		/* also the max paca allocated 	 */
+#endif
 	li	r5,0			/* logical cpu id                */
 1:
 	sldi	r9,r5,3			/* get paca_ptrs[] index from cpu id */
diff --git a/arch/x86/configs/openeuler_defconfig b/arch/x86/configs/openeuler_defconfig
index 3db754e798115fcad86c573e8cf1198307ef5e29..4f912e543270cb46bc561af4f18c642e7675b4e3 100644
--- a/arch/x86/configs/openeuler_defconfig
+++ b/arch/x86/configs/openeuler_defconfig
@@ -8135,6 +8135,7 @@ CONFIG_DMA_COHERENT_POOL=y
 CONFIG_SGL_ALLOC=y
 CONFIG_CHECK_SIGNATURE=y
 CONFIG_CPUMASK_OFFSTACK=y
+# CONFIG_FORCE_NR_CPUS is not set
 CONFIG_CPU_RMAP=y
 CONFIG_DQL=y
 CONFIG_GLOB=y
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index ba5cf8ff7374fa1d4ba54973322d92da87065b4d..2b37b16685ed48a14267d24b290955b709c2fada 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1284,7 +1284,7 @@ static void __init smp_sanity_check(void)
 			nr++;
 		}
 
-		nr_cpu_ids = 8;
+		set_nr_cpu_ids(8);
 	}
 #endif
 
@@ -1526,7 +1526,7 @@ __init void prefill_possible_map(void)
 		possible = i;
 	}
 
-	nr_cpu_ids = possible;
+	set_nr_cpu_ids(possible);
 
 	pr_info("Allowing %d CPUs, %d hotplug CPUs\n",
 		possible, max_t(int, possible - num_processors, 0));
diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c
index 755e939db3ed3abcf3ecd21e64aa000a8cdd3508..26babb8a1897a9bf8885d2e7d9fe8f7f0490e1a2 100644
--- a/arch/x86/xen/smp_pv.c
+++ b/arch/x86/xen/smp_pv.c
@@ -182,7 +182,7 @@ static void __init _get_smp_config(unsigned int early)
 	 * hypercall to expand the max number of VCPUs an already
 	 * running guest has. So cap it up to X. */
 	if (subtract)
-		nr_cpu_ids = nr_cpu_ids - subtract;
+		set_nr_cpu_ids(nr_cpu_ids - subtract);
 #endif
 
 }
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 7cdec529b1d956a4698d972d357de894fcecc335..2e50162d9908a815cd27309ad0c59646597b51d4 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -33,19 +33,23 @@ typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
  */
 #define cpumask_pr_args(maskp)		nr_cpu_ids, cpumask_bits(maskp)
 
-#if NR_CPUS == 1
-#define nr_cpu_ids		1U
+#if (NR_CPUS == 1) || defined(CONFIG_FORCE_NR_CPUS)
+#define nr_cpu_ids ((unsigned int)NR_CPUS)
 #else
 extern unsigned int nr_cpu_ids;
 #endif
 
-#ifdef CONFIG_CPUMASK_OFFSTACK
-/* Assuming NR_CPUS is huge, a runtime limit is more efficient.  Also,
- * not all bits may be allocated. */
-#define nr_cpumask_bits	nr_cpu_ids
+static inline void set_nr_cpu_ids(unsigned int nr)
+{
+#if (NR_CPUS == 1) || defined(CONFIG_FORCE_NR_CPUS)
+	WARN_ON(nr != nr_cpu_ids);
 #else
-#define nr_cpumask_bits	((unsigned int)NR_CPUS)
+	nr_cpu_ids = nr;
 #endif
+}
+
+/* Deprecated. Always use nr_cpu_ids. */
+#define nr_cpumask_bits	nr_cpu_ids
 
 /*
  * The following particular system cpumasks and operations manage
@@ -65,10 +69,6 @@ extern unsigned int nr_cpu_ids;
  *  cpu_online_mask is the dynamic subset of cpu_present_mask,
  *  indicating those CPUs available for scheduling.
  *
- *  If HOTPLUG is enabled, then cpu_possible_mask is forced to have
- *  all NR_CPUS bits set, otherwise it is just the set of CPUs that
- *  ACPI reports present at boot.
- *
  *  If HOTPLUG is enabled, then cpu_present_mask varies dynamically,
  *  depending on what ACPI reports as currently plugged in, otherwise
  *  cpu_present_mask is just a copy of cpu_possible_mask.
diff --git a/kernel/smp.c b/kernel/smp.c
index 2023c022ad5f1c740d520a35da6b6d390d781b37..4b13a7ef6a31586ee8fbf42449d0b8245b467646 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -834,7 +834,7 @@ static int __init nrcpus(char *str)
 	int nr_cpus;
 
 	if (get_option(&str, &nr_cpus) && nr_cpus > 0 && nr_cpus < nr_cpu_ids)
-		nr_cpu_ids = nr_cpus;
+		set_nr_cpu_ids(nr_cpus);
 
 	return 0;
 }
@@ -852,14 +852,16 @@ static int __init maxcpus(char *str)
 
 early_param("maxcpus", maxcpus);
 
+#if (NR_CPUS > 1) && !defined(CONFIG_FORCE_NR_CPUS)
 /* Setup number of possible processor ids */
 unsigned int nr_cpu_ids __read_mostly = NR_CPUS;
 EXPORT_SYMBOL(nr_cpu_ids);
+#endif
 
 /* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
 void __init setup_nr_cpu_ids(void)
 {
-	nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1;
+	set_nr_cpu_ids(find_last_bit(cpumask_bits(cpu_possible_mask), NR_CPUS) + 1);
 }
 
 /* Called by boot processor to activate the rest. */
diff --git a/lib/Kconfig b/lib/Kconfig
index 36326864249dd9d38bd90b3f74c1f7a19dc44ebc..8026964596fd72b6a5d4c46ea7f56d00c4f95c21 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -494,6 +494,15 @@ config CPUMASK_OFFSTACK
 	  them on the stack.  This is a bit more expensive, but avoids
 	  stack overflow.
 
+config FORCE_NR_CPUS
+       bool "NR_CPUS is set to an actual number of CPUs"
+       depends on SMP
+       help
+         Say Yes if you have NR_CPUS set to an actual number of possible
+         CPUs in your system, not to a default value. This forces the core
+         code to rely on compile-time value and optimize kernel routines
+         better.
+
 config CPU_RMAP
 	bool
 	depends on SMP