[PATCH] more for_each_cpu() conversions

When we stop allocating percpu memory for not-possible CPUs we must not touch
the percpu data for not-possible CPUs at all.  The correct way of doing this
is to test cpu_possible() or to use for_each_cpu().

This patch is a kernel-wide sweep of all instances of NR_CPUS.  I found very
few instances of this bug, if any.  But the patch converts lots of open-coded
test to use the preferred helper macros.

Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Acked-by: Kyle McMartin <kyle@parisc-linux.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Christian Zankel <chris@zankel.net>
Cc: Philippe Elie <phil.el@wanadoo.fr>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Jens Axboe <axboe@suse.de>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/cris/kernel/irq.c

@@ -52,8 +52,7 @@ int show_interrupts(struct seq_file *p, void *v)
 
 	if (i == 0) {
 		seq_printf(p, "           ");
-		for (j=0; j<NR_CPUS; j++)
-			if (cpu_online(j))
+		for_each_online_cpu(j)
 			seq_printf(p, "CPU%d       ",j);
 		seq_putc(p, '\n');
 	}
@@ -67,8 +66,7 @@ int show_interrupts(struct seq_file *p, void *v)
 #ifndef CONFIG_SMP
 		seq_printf(p, "%10u ", kstat_irqs(i));
 #else
-		for (j = 0; j < NR_CPUS; j++)
-			if (cpu_online(j))
+		for_each_online_cpu(j)
 			seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
 #endif
 		seq_printf(p, " %14s", irq_desc[i].handler->typename);

arch/frv/kernel/irq.c

@@ -75,8 +75,7 @@ int show_interrupts(struct seq_file *p, void *v)
 	switch (i) {
 	case 0:
 		seq_printf(p, "           ");
-		for (j = 0; j < NR_CPUS; j++)
-			if (cpu_online(j))
+		for_each_online_cpu(j)
 			seq_printf(p, "CPU%d       ",j);
 
 		seq_putc(p, '\n');
@@ -100,8 +99,7 @@ int show_interrupts(struct seq_file *p, void *v)
 #ifndef CONFIG_SMP
 		seq_printf(p, "%10u ", kstat_irqs(i));
 #else
-		for (j = 0; j < NR_CPUS; j++)
-			if (cpu_online(j))
+		for_each_online_cpu(j)
 			seq_printf(p, "%10u ", kstat_cpu(j).irqs[i - 1]);
 #endif
 

arch/i386/kernel/cpu/cpufreq/powernow-k8.c

@@ -1145,9 +1145,7 @@ static int __cpuinit powernowk8_init(void)
 {
 	unsigned int i, supported_cpus = 0;
 
-	for (i=0; i<NR_CPUS; i++) {
-		if (!cpu_online(i))
-			continue;
+	for_each_cpu(i) {
 		if (check_supported_cpu(i))
 			supported_cpus++;
 	}

arch/i386/kernel/io_apic.c

@@ -351,8 +351,8 @@ static inline void rotate_irqs_among_cpus(unsigned long useful_load_threshold)
 {
 	int i, j;
 	Dprintk("Rotating IRQs among CPUs.\n");
-	for (i = 0; i < NR_CPUS; i++) {
-		for (j = 0; cpu_online(i) && (j < NR_IRQS); j++) {
+	for_each_online_cpu(i) {
+		for (j = 0; j < NR_IRQS; j++) {
 			if (!irq_desc[j].action)
 				continue;
 			/* Is it a significant load ?  */
@@ -381,7 +381,7 @@ static void do_irq_balance(void)
 	unsigned long imbalance = 0;
 	cpumask_t allowed_mask, target_cpu_mask, tmp;
 
-	for (i = 0; i < NR_CPUS; i++) {
+	for_each_cpu(i) {
 		int package_index;
 		CPU_IRQ(i) = 0;
 		if (!cpu_online(i))
@@ -422,9 +422,7 @@ static void do_irq_balance(void)
 		}
 	}
 	/* Find the least loaded processor package */
-	for (i = 0; i < NR_CPUS; i++) {
-		if (!cpu_online(i))
-			continue;
+	for_each_online_cpu(i) {
 		if (i != CPU_TO_PACKAGEINDEX(i))
 			continue;
 		if (min_cpu_irq > CPU_IRQ(i)) {
@@ -441,9 +439,7 @@ tryanothercpu:
 	 */
 	tmp_cpu_irq = 0;
 	tmp_loaded = -1;
-	for (i = 0; i < NR_CPUS; i++) {
-		if (!cpu_online(i))
-			continue;
+	for_each_online_cpu(i) {
 		if (i != CPU_TO_PACKAGEINDEX(i))
 			continue;
 		if (max_cpu_irq <= CPU_IRQ(i)) 
@@ -619,9 +615,7 @@ static int __init balanced_irq_init(void)
 	if (smp_num_siblings > 1 && !cpus_empty(tmp))
 		physical_balance = 1;
 
-	for (i = 0; i < NR_CPUS; i++) {
-		if (!cpu_online(i))
-			continue;
+	for_each_online_cpu(i) {
 		irq_cpu_data[i].irq_delta = kmalloc(sizeof(unsigned long) * NR_IRQS, GFP_KERNEL);
 		irq_cpu_data[i].last_irq = kmalloc(sizeof(unsigned long) * NR_IRQS, GFP_KERNEL);
 		if (irq_cpu_data[i].irq_delta == NULL || irq_cpu_data[i].last_irq == NULL) {
@@ -638,9 +632,11 @@ static int __init balanced_irq_init(void)
 	else 
 		printk(KERN_ERR "balanced_irq_init: failed to spawn balanced_irq");
 failed:
-	for (i = 0; i < NR_CPUS; i++) {
+	for_each_cpu(i) {
 		kfree(irq_cpu_data[i].irq_delta);
+		irq_cpu_data[i].irq_delta = NULL;
 		kfree(irq_cpu_data[i].last_irq);
+		irq_cpu_data[i].last_irq = NULL;
 	}
 	return 0;
 }

arch/i386/kernel/nmi.c

@@ -143,7 +143,7 @@ static int __init check_nmi_watchdog(void)
 	local_irq_enable();
 	mdelay((10*1000)/nmi_hz); // wait 10 ticks
 
-	for (cpu = 0; cpu < NR_CPUS; cpu++) {
+	for_each_cpu(cpu) {
 #ifdef CONFIG_SMP
 		/* Check cpu_callin_map here because that is set
 		   after the timer is started. */
@@ -510,7 +510,7 @@ void touch_nmi_watchdog (void)
 	 * Just reset the alert counters, (other CPUs might be
 	 * spinning on locks we hold):
 	 */
-	for (i = 0; i < NR_CPUS; i++)
+	for_each_cpu(i)
 		alert_counter[i] = 0;
 
 	/*

arch/i386/oprofile/nmi_int.c

@@ -122,7 +122,7 @@ static void nmi_save_registers(void * dummy)
 static void free_msrs(void)
 {
 	int i;
-	for (i = 0; i < NR_CPUS; ++i) {
+	for_each_cpu(i) {
 		kfree(cpu_msrs[i].counters);
 		cpu_msrs[i].counters = NULL;
 		kfree(cpu_msrs[i].controls);
@@ -138,10 +138,7 @@ static int allocate_msrs(void)
 	size_t counters_size = sizeof(struct op_msr) * model->num_counters;
 
 	int i;
-	for (i = 0; i < NR_CPUS; ++i) {
-		if (!cpu_online(i))
-			continue;
-
+	for_each_online_cpu(i) {
 		cpu_msrs[i].counters = kmalloc(counters_size, GFP_KERNEL);
 		if (!cpu_msrs[i].counters) {
 			success = 0;

arch/m32r/kernel/irq.c

@@ -37,8 +37,7 @@ int show_interrupts(struct seq_file *p, void *v)
 
 	if (i == 0) {
 		seq_printf(p, "           ");
-		for (j=0; j<NR_CPUS; j++)
-			if (cpu_online(j))
+		for_each_online_cpu(j)
 			seq_printf(p, "CPU%d       ",j);
 		seq_putc(p, '\n');
 	}
@@ -52,8 +51,7 @@ int show_interrupts(struct seq_file *p, void *v)
 #ifndef CONFIG_SMP
 		seq_printf(p, "%10u ", kstat_irqs(i));
 #else
-		for (j = 0; j < NR_CPUS; j++)
-			if (cpu_online(j))
+		for_each_online_cpu(j)
 			seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
 #endif
 		seq_printf(p, " %14s", irq_desc[i].handler->typename);

arch/mips/kernel/irq.c

@@ -68,8 +68,7 @@ int show_interrupts(struct seq_file *p, void *v)
 
 	if (i == 0) {
 		seq_printf(p, "           ");
-		for (j=0; j<NR_CPUS; j++)
-			if (cpu_online(j))
+		for_each_online_cpu(j)
 			seq_printf(p, "CPU%d       ",j);
 		seq_putc(p, '\n');
 	}
@@ -83,8 +82,7 @@ int show_interrupts(struct seq_file *p, void *v)
 #ifndef CONFIG_SMP
 		seq_printf(p, "%10u ", kstat_irqs(i));
 #else
-		for (j = 0; j < NR_CPUS; j++)
-			if (cpu_online(j))
+		for_each_online_cpu(j)
 			seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
 #endif
 		seq_printf(p, " %14s", irq_desc[i].handler->typename);

arch/mips/kernel/smp.c

@@ -167,8 +167,8 @@ int smp_call_function (void (*func) (void *info), void *info, int retry,
 	mb();
 
 	/* Send a message to all other CPUs and wait for them to respond */
-	for (i = 0; i < NR_CPUS; i++)
-		if (cpu_online(i) && i != cpu)
+	for_each_online_cpu(i)
+		if (i != cpu)
 			core_send_ipi(i, SMP_CALL_FUNCTION);
 
 	/* Wait for response */

arch/mips/sgi-ip27/ip27-irq.c

@@ -88,12 +88,9 @@ static inline int find_level(cpuid_t *cpunum, int irq)
 {
 	int cpu, i;
 
-	for (cpu = 0; cpu <= NR_CPUS; cpu++) {
+	for_each_online_cpu(cpu) {
 		struct slice_data *si = cpu_data[cpu].data;
 
-		if (!cpu_online(cpu))
-			continue;
-
 		for (i = BASE_PCI_IRQ; i < LEVELS_PER_SLICE; i++)
 			if (si->level_to_irq[i] == irq) {
 				*cpunum = cpu;

arch/parisc/kernel/smp.c

@@ -298,8 +298,8 @@ send_IPI_allbutself(enum ipi_message_type op)
 {
 	int i;
 	
-	for (i = 0; i < NR_CPUS; i++) {
-		if (cpu_online(i) && i != smp_processor_id())
+	for_each_online_cpu(i) {
+		if (i != smp_processor_id())
 			send_IPI_single(i, op);
 	}
 }
@@ -643,15 +643,14 @@ int sys_cpus(int argc, char **argv)
 	if ( argc == 1 ){
 	
 #ifdef DUMP_MORE_STATE
-		for(i=0; i<NR_CPUS; i++) {
+		for_each_online_cpu(i) {
 			int cpus_per_line = 4;
-			if(cpu_online(i)) {
+
 			if (j++ % cpus_per_line)
 				printk(" %3d",i);
 			else
 				printk("\n %3d",i);
 		}
-		}
 		printk("\n"); 
 #else
 	    	printk("\n 0\n"); 
@@ -659,9 +658,7 @@ int sys_cpus(int argc, char **argv)
 	} else if((argc==2) && !(strcmp(argv[1],"-l"))) {
 		printk("\nCPUSTATE  TASK CPUNUM CPUID HARDCPU(HPA)\n");
 #ifdef DUMP_MORE_STATE
-		for(i=0;i<NR_CPUS;i++) {
-			if (!cpu_online(i))
-				continue;
+		for_each_online_cpu(i) {
 			if (cpu_data[i].cpuid != NO_PROC_ID) {
 				switch(cpu_data[i].state) {
 					case STATE_RENDEZVOUS:
@@ -695,9 +692,7 @@ int sys_cpus(int argc, char **argv)
 	} else if ((argc==2) && !(strcmp(argv[1],"-s"))) { 
 #ifdef DUMP_MORE_STATE
      		printk("\nCPUSTATE   CPUID\n");
-		for (i=0;i<NR_CPUS;i++) {
-			if (!cpu_online(i))
-				continue;
+		for_each_online_cpu(i) {
 			if (cpu_data[i].cpuid != NO_PROC_ID) {
 				switch(cpu_data[i].state) {
 					case STATE_RENDEZVOUS:

arch/powerpc/kernel/irq.c

@@ -135,8 +135,7 @@ skip:
 #ifdef CONFIG_TAU_INT
 		if (tau_initialized){
 			seq_puts(p, "TAU: ");
-			for (j = 0; j < NR_CPUS; j++)
-				if (cpu_online(j))
+			for_each_online_cpu(j)
 				seq_printf(p, "%10u ", tau_interrupts(j));
 			seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 		}

arch/powerpc/kernel/setup-common.c

@@ -162,8 +162,7 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 #if defined(CONFIG_SMP) && defined(CONFIG_PPC32)
 		unsigned long bogosum = 0;
 		int i;
-		for (i = 0; i < NR_CPUS; ++i)
-			if (cpu_online(i))
+		for_each_online_cpu(i)
 			bogosum += loops_per_jiffy;
 		seq_printf(m, "total bogomips\t: %lu.%02lu\n",
 			   bogosum/(500000/HZ), bogosum/(5000/HZ) % 100);

arch/powerpc/kernel/setup_32.c

@@ -272,8 +272,7 @@ int __init ppc_init(void)
 	if ( ppc_md.progress ) ppc_md.progress("             ", 0xffff);
 
 	/* register CPU devices */
-	for (i = 0; i < NR_CPUS; i++)
-		if (cpu_possible(i))
+	for_each_cpu(i)
 		register_cpu(&cpu_devices[i], i, NULL);
 
 	/* call platform init */

arch/powerpc/platforms/powermac/smp.c

@@ -191,9 +191,7 @@ static void smp_psurge_message_pass(int target, int msg)
 	if (num_online_cpus() < 2)
 		return;
 
-	for (i = 0; i < NR_CPUS; i++) {
-		if (!cpu_online(i))
-			continue;
+	for_each_online_cpu(i) {
 		if (target == MSG_ALL
 		    || (target == MSG_ALL_BUT_SELF && i != smp_processor_id())
 		    || target == i) {

arch/ppc/kernel/setup.c

@@ -168,8 +168,7 @@ int show_cpuinfo(struct seq_file *m, void *v)
 		/* Show summary information */
 #ifdef CONFIG_SMP
 		unsigned long bogosum = 0;
-		for (i = 0; i < NR_CPUS; ++i)
-			if (cpu_online(i))
+		for_each_online_cpu(i)
 			bogosum += cpu_data[i].loops_per_jiffy;
 		seq_printf(m, "total bogomips\t: %lu.%02lu\n",
 			   bogosum/(500000/HZ), bogosum/(5000/HZ) % 100);
@@ -712,8 +711,7 @@ int __init ppc_init(void)
 	if ( ppc_md.progress ) ppc_md.progress("             ", 0xffff);
 
 	/* register CPU devices */
-	for (i = 0; i < NR_CPUS; i++)
-		if (cpu_possible(i))
+	for_each_cpu(i)
 		register_cpu(&cpu_devices[i], i, NULL);
 
 	/* call platform init */

arch/s390/kernel/smp.c

@@ -799,9 +799,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
          */
 	print_cpu_info(&S390_lowcore.cpu_data);
 
-        for(i = 0; i < NR_CPUS; i++) {
-		if (!cpu_possible(i))
-			continue;
+        for_each_cpu(i) {
 		lowcore_ptr[i] = (struct _lowcore *)
 			__get_free_pages(GFP_KERNEL|GFP_DMA, 
 					sizeof(void*) == 8 ? 1 : 0);

arch/sh/kernel/irq.c

@@ -35,8 +35,7 @@ int show_interrupts(struct seq_file *p, void *v)
 
 	if (i == 0) {
 		seq_puts(p, "           ");
-		for (j=0; j<NR_CPUS; j++)
-			if (cpu_online(j))
+		for_each_online_cpu(j)
 			seq_printf(p, "CPU%d       ",j);
 		seq_putc(p, '\n');
 	}

arch/sh/kernel/setup.c

@@ -404,8 +404,7 @@ static int __init topology_init(void)
 {
 	int cpu_id;
 
-	for (cpu_id = 0; cpu_id < NR_CPUS; cpu_id++)
-		if (cpu_possible(cpu_id))
+	for_each_cpu(cpu_id)
 		register_cpu(&cpu[cpu_id], cpu_id, NULL);
 
 	return 0;

arch/sh64/kernel/irq.c

@@ -53,8 +53,7 @@ int show_interrupts(struct seq_file *p, void *v)
 
 	if (i == 0) {
 		seq_puts(p, "           ");
-		for (j=0; j<NR_CPUS; j++)
-			if (cpu_online(j))
+		for_each_online_cpu(j)
 			seq_printf(p, "CPU%d       ",j);
 		seq_putc(p, '\n');
 	}

arch/sparc/kernel/irq.c

@@ -184,8 +184,7 @@ int show_interrupts(struct seq_file *p, void *v)
 #ifndef CONFIG_SMP
 		seq_printf(p, "%10u ", kstat_irqs(i));
 #else
-		for (j = 0; j < NR_CPUS; j++) {
-			if (cpu_online(j))
+		for_each_online_cpu(j) {
 			seq_printf(p, "%10u ",
 				    kstat_cpu(cpu_logical_map(j)).irqs[i]);
 		}

arch/sparc/kernel/smp.c

@@ -243,8 +243,7 @@ int setup_profiling_timer(unsigned int multiplier)
 		return -EINVAL;
 
 	spin_lock_irqsave(&prof_setup_lock, flags);
-	for(i = 0; i < NR_CPUS; i++) {
-		if (cpu_possible(i))
+	for_each_cpu(i) {
 		load_profile_irq(i, lvl14_resolution / multiplier);
 		prof_multiplier(i) = multiplier;
 	}
@@ -273,8 +272,7 @@ void smp_bogo(struct seq_file *m)
 {
 	int i;
 	
-	for (i = 0; i < NR_CPUS; i++) {
-		if (cpu_online(i))
+	for_each_online_cpu(i) {
 		seq_printf(m,
 			   "Cpu%dBogo\t: %lu.%02lu\n",
 			   i,
@@ -288,8 +286,6 @@ void smp_info(struct seq_file *m)
 	int i;
 
 	seq_printf(m, "State:\n");
-	for (i = 0; i < NR_CPUS; i++) {
-		if (cpu_online(i))
+	for_each_online_cpu(i)
 		seq_printf(m, "CPU%d\t\t: online\n", i);
-	}
 }

arch/sparc/kernel/sun4d_irq.c

@@ -103,11 +103,9 @@ found_it:	seq_printf(p, "%3d: ", i);
 #ifndef CONFIG_SMP
 		seq_printf(p, "%10u ", kstat_irqs(i));
 #else
-		for (x = 0; x < NR_CPUS; x++) {
-			if (cpu_online(x))
+		for_each_online_cpu(x)
 			seq_printf(p, "%10u ",
 			       kstat_cpu(cpu_logical_map(x)).irqs[i]);
-		}
 #endif
 		seq_printf(p, "%c %s",
 			(action->flags & SA_INTERRUPT) ? '+' : ' ',

arch/sparc/kernel/sun4d_smp.c

@@ -249,12 +249,10 @@ void __init smp4d_boot_cpus(void)
 	} else {
 		unsigned long bogosum = 0;
 		
-		for(i = 0; i < NR_CPUS; i++) {
-			if (cpu_isset(i, cpu_present_map)) {
+		for_each_present_cpu(i) {
 			bogosum += cpu_data(i).udelay_val;
 			smp_highest_cpu = i;
 		}
-		}
 		SMP_PRINTK(("Total of %d Processors activated (%lu.%02lu BogoMIPS).\n", cpucount + 1, bogosum/(500000/HZ), (bogosum/(5000/HZ))%100));
 		printk("Total of %d Processors activated (%lu.%02lu BogoMIPS).\n",
 		       cpucount + 1,

arch/sparc/kernel/sun4m_smp.c

@@ -218,10 +218,8 @@ void __init smp4m_boot_cpus(void)
 		cpu_present_map = cpumask_of_cpu(smp_processor_id());
 	} else {
 		unsigned long bogosum = 0;
-		for(i = 0; i < NR_CPUS; i++) {
-			if (cpu_isset(i, cpu_present_map))
+		for_each_present_cpu(i)
 			bogosum += cpu_data(i).udelay_val;
-		}
 		printk("Total of %d Processors activated (%lu.%02lu BogoMIPS).\n",
 		       cpucount + 1,
 		       bogosum/(500000/HZ),

arch/sparc64/kernel/irq.c

@@ -117,9 +117,7 @@ int show_interrupts(struct seq_file *p, void *v)
 #ifndef CONFIG_SMP
 		seq_printf(p, "%10u ", kstat_irqs(i));
 #else
-		for (j = 0; j < NR_CPUS; j++) {
-			if (!cpu_online(j))
-				continue;
+		for_each_online_cpu(j) {
 			seq_printf(p, "%10u ",
 				   kstat_cpu(j).irqs[i]);
 		}

arch/sparc64/kernel/smp.c

@@ -57,19 +57,15 @@ void smp_info(struct seq_file *m)
 	int i;
 	
 	seq_printf(m, "State:\n");
-	for (i = 0; i < NR_CPUS; i++) {
-		if (cpu_online(i))
-			seq_printf(m,
-				   "CPU%d:\t\tonline\n", i);
-	}
+	for_each_online_cpu(i)
+		seq_printf(m, "CPU%d:\t\tonline\n", i);
 }
 
 void smp_bogo(struct seq_file *m)
 {
 	int i;
 	
-	for (i = 0; i < NR_CPUS; i++)
-		if (cpu_online(i))
+	for_each_online_cpu(i)
 		seq_printf(m,
 			   "Cpu%dBogo\t: %lu.%02lu\n"
 			   "Cpu%dClkTck\t: %016lx\n",
@@ -1282,7 +1278,7 @@ int setup_profiling_timer(unsigned int multiplier)
 		return -EINVAL;
 
 	spin_lock_irqsave(&prof_setup_lock, flags);
-	for (i = 0; i < NR_CPUS; i++)
+	for_each_cpu(i)
 		prof_multiplier(i) = multiplier;
 	current_tick_offset = (timer_tick_offset / multiplier);
 	spin_unlock_irqrestore(&prof_setup_lock, flags);
@@ -1384,10 +1380,8 @@ void __init smp_cpus_done(unsigned int max_cpus)
 	unsigned long bogosum = 0;
 	int i;
 
-	for (i = 0; i < NR_CPUS; i++) {
-		if (cpu_online(i))
+	for_each_online_cpu(i)
 		bogosum += cpu_data(i).udelay_val;
-	}
 	printk("Total of %ld processors activated "
 	       "(%lu.%02lu BogoMIPS).\n",
 	       (long) num_online_cpus(),

arch/x86_64/kernel/irq.c

@@ -38,8 +38,7 @@ int show_interrupts(struct seq_file *p, void *v)
 
 	if (i == 0) {
 		seq_printf(p, "           ");
-		for (j=0; j<NR_CPUS; j++)
-			if (cpu_online(j))
+		for_each_online_cpu(j)
 			seq_printf(p, "CPU%d       ",j);
 		seq_putc(p, '\n');
 	}
@@ -53,10 +52,8 @@ int show_interrupts(struct seq_file *p, void *v)
 #ifndef CONFIG_SMP
 		seq_printf(p, "%10u ", kstat_irqs(i));
 #else
-		for (j=0; j<NR_CPUS; j++)
-			if (cpu_online(j))
-			seq_printf(p, "%10u ",
-				kstat_cpu(j).irqs[i]);
+		for_each_online_cpu(j)
+			seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
 #endif
 		seq_printf(p, " %14s", irq_desc[i].handler->typename);
 
@@ -68,14 +65,12 @@ skip:
 		spin_unlock_irqrestore(&irq_desc[i].lock, flags);
 	} else if (i == NR_IRQS) {
 		seq_printf(p, "NMI: ");
-		for (j = 0; j < NR_CPUS; j++)
-			if (cpu_online(j))
+		for_each_online_cpu(j)
 			seq_printf(p, "%10u ", cpu_pda(j)->__nmi_count);
 		seq_putc(p, '\n');
 #ifdef CONFIG_X86_LOCAL_APIC
 		seq_printf(p, "LOC: ");
-		for (j = 0; j < NR_CPUS; j++)
-			if (cpu_online(j))
+		for_each_online_cpu(j)
 			seq_printf(p, "%10u ", cpu_pda(j)->apic_timer_irqs);
 		seq_putc(p, '\n');
 #endif

arch/x86_64/kernel/nmi.c

@@ -162,9 +162,7 @@ int __init check_nmi_watchdog (void)
 	local_irq_enable();
 	mdelay((10*1000)/nmi_hz); // wait 10 ticks
 
-	for (cpu = 0; cpu < NR_CPUS; cpu++) {
-		if (!cpu_online(cpu))
-			continue;
+	for_each_online_cpu(cpu) {
 		if (cpu_pda(cpu)->__nmi_count - counts[cpu] <= 5) {
 			endflag = 1;
 			printk("CPU#%d: NMI appears to be stuck (%d->%d)!\n",

arch/xtensa/kernel/irq.c

@@ -83,8 +83,7 @@ int show_interrupts(struct seq_file *p, void *v)
 
 	if (i == 0) {
 		seq_printf(p, "           ");
-		for (j=0; j<NR_CPUS; j++)
-			if (cpu_online(j))
+		for_each_online_cpu(j)
 			seq_printf(p, "CPU%d       ",j);
 		seq_putc(p, '\n');
 	}
@@ -98,8 +97,7 @@ int show_interrupts(struct seq_file *p, void *v)
 #ifndef CONFIG_SMP
 		seq_printf(p, "%10u ", kstat_irqs(i));
 #else
-		for (j = 0; j < NR_CPUS; j++)
-			if (cpu_online(j))
+		for_each_online_cpu(j)
 			seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
 #endif
 		seq_printf(p, " %14s", irq_desc[i].handler->typename);
@@ -113,8 +111,7 @@ skip:
 		spin_unlock_irqrestore(&irq_desc[i].lock, flags);
 	} else if (i == NR_IRQS) {
 		seq_printf(p, "NMI: ");
-		for (j = 0; j < NR_CPUS; j++)
-			if (cpu_online(j))
+		for_each_online_cpu(j)
 			seq_printf(p, "%10u ", nmi_count(j));
 		seq_putc(p, '\n');
 		seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));

drivers/net/loopback.c

@@ -172,11 +172,9 @@ static struct net_device_stats *get_stats(struct net_device *dev)
 
 	memset(stats, 0, sizeof(struct net_device_stats));
 
-	for (i=0; i < NR_CPUS; i++) {
+	for_each_cpu(i) {
 		struct net_device_stats *lb_stats;
 
-		if (!cpu_possible(i)) 
-			continue;
 		lb_stats = &per_cpu(loopback_stats, i);
 		stats->rx_bytes   += lb_stats->rx_bytes;
 		stats->tx_bytes   += lb_stats->tx_bytes;

drivers/oprofile/cpu_buffer.c

@@ -38,9 +38,8 @@ void free_cpu_buffers(void)
 {
 	int i;
  
-	for_each_online_cpu(i) {
+	for_each_online_cpu(i)
 		vfree(cpu_buffer[i].buffer);
-	}
 }
 
 int alloc_cpu_buffers(void)

fs/xfs/linux-2.6/xfs_stats.c

@@ -62,18 +62,15 @@ xfs_read_xfsstats(
 		while (j < xstats[i].endpoint) {
 			val = 0;
 			/* sum over all cpus */
-			for (c = 0; c < NR_CPUS; c++) {
-				if (!cpu_possible(c)) continue;
+			for_each_cpu(c)
 				val += *(((__u32*)&per_cpu(xfsstats, c) + j));
-			}
 			len += sprintf(buffer + len, " %u", val);
 			j++;
 		}
 		buffer[len++] = '\n';
 	}
 	/* extra precision counters */
-	for (i = 0; i < NR_CPUS; i++) {
-		if (!cpu_possible(i)) continue;
+	for_each_cpu(i) {
 		xs_xstrat_bytes += per_cpu(xfsstats, i).xs_xstrat_bytes;
 		xs_write_bytes += per_cpu(xfsstats, i).xs_write_bytes;
 		xs_read_bytes += per_cpu(xfsstats, i).xs_read_bytes;

fs/xfs/linux-2.6/xfs_sysctl.c

@@ -38,8 +38,7 @@ xfs_stats_clear_proc_handler(
 
 	if (!ret && write && *valp) {
 		printk("XFS Clearing xfsstats\n");
-		for (c = 0; c < NR_CPUS; c++) {
-			if (!cpu_possible(c)) continue;
+		for_each_cpu(c) {
 			preempt_disable();
 			/* save vn_active, it's a universal truth! */
 			vn_active = per_cpu(xfsstats, c).vn_active;

include/asm-alpha/mmu_context.h

@@ -231,8 +231,7 @@ init_new_context(struct task_struct *tsk, struct mm_struct *mm)
 {
 	int i;
 
-	for (i = 0; i < NR_CPUS; i++)
-		if (cpu_online(i))
+	for_each_online_cpu(i)
 		mm->context[i] = 0;
 	if (tsk != current)
 		task_thread_info(tsk)->pcb.ptbr

include/asm-alpha/topology.h

@@ -27,8 +27,8 @@ static inline cpumask_t node_to_cpumask(int node)
 	cpumask_t node_cpu_mask = CPU_MASK_NONE;
 	int cpu;
 
-	for(cpu = 0; cpu < NR_CPUS; cpu++) {
-		if (cpu_online(cpu) && (cpu_to_node(cpu) == node))
+	for_each_online_cpu(cpu) {
+		if (cpu_to_node(cpu) == node)
 			cpu_set(cpu, node_cpu_mask);
 	}
 

include/asm-generic/percpu.h

@@ -19,8 +19,7 @@ extern unsigned long __per_cpu_offset[NR_CPUS];
 #define percpu_modcopy(pcpudst, src, size)			\
 do {								\
 	unsigned int __i;					\
-	for (__i = 0; __i < NR_CPUS; __i++)			\
-		if (cpu_possible(__i))				\
+	for_each_cpu(__i)					\
 		memcpy((pcpudst)+__per_cpu_offset[__i],		\
 		       (src), (size));				\
 } while (0)

include/asm-powerpc/percpu.h

@@ -27,8 +27,7 @@
 #define percpu_modcopy(pcpudst, src, size)			\
 do {								\
 	unsigned int __i;					\
-	for (__i = 0; __i < NR_CPUS; __i++)			\
-		if (cpu_possible(__i))				\
+	for_each_cpu(__i)					\
 		memcpy((pcpudst)+__per_cpu_offset(__i),		\
 		       (src), (size));				\
 } while (0)

include/asm-s390/percpu.h

@@ -46,8 +46,7 @@ extern unsigned long __per_cpu_offset[NR_CPUS];
 #define percpu_modcopy(pcpudst, src, size)			\
 do {								\
 	unsigned int __i;					\
-	for (__i = 0; __i < NR_CPUS; __i++)			\
-		if (cpu_possible(__i))				\
+	for_each_cpu(__i)					\
 		memcpy((pcpudst)+__per_cpu_offset[__i],		\
 		       (src), (size));				\
 } while (0)

include/asm-sparc64/percpu.h

@@ -26,8 +26,7 @@ register unsigned long __local_per_cpu_offset asm("g5");
 #define percpu_modcopy(pcpudst, src, size)			\
 do {								\
 	unsigned int __i;					\
-	for (__i = 0; __i < NR_CPUS; __i++)			\
-		if (cpu_possible(__i))				\
+	for_each_cpu(__i)					\
 		memcpy((pcpudst)+__per_cpu_offset(__i),		\
 		       (src), (size));				\
 } while (0)

include/asm-x86_64/percpu.h

@@ -26,8 +26,7 @@
 #define percpu_modcopy(pcpudst, src, size)			\
 do {								\
 	unsigned int __i;					\
-	for (__i = 0; __i < NR_CPUS; __i++)			\
-		if (cpu_possible(__i))				\
+	for_each_cpu(__i)					\
 		memcpy((pcpudst)+__per_cpu_offset(__i),		\
 		       (src), (size));				\
 } while (0)

include/linux/genhd.h

@@ -149,22 +149,16 @@ struct disk_attribute {
 ({									\
 	typeof(gendiskp->dkstats->field) res = 0;			\
 	int i;								\
-	for (i=0; i < NR_CPUS; i++) {					\
-		if (!cpu_possible(i))					\
-			continue;					\
+	for_each_cpu(i)							\
 		res += per_cpu_ptr(gendiskp->dkstats, i)->field;	\
-	}								\
 	res;								\
 })
 
 static inline void disk_stat_set_all(struct gendisk *gendiskp, int value)	{
 	int i;
-	for (i=0; i < NR_CPUS; i++) {
-		if (cpu_possible(i)) {
+	for_each_cpu(i)
 		memset(per_cpu_ptr(gendiskp->dkstats, i), value,
 				sizeof (struct disk_stats));
-		}
-	}
 }		
 				
 #else