[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>

3 files changed, 7 insertions, 12 deletions

diff --git a/arch/mips/kernel/irq.c b/arch/mips/kernel/irq.c
index 7d93992e462c..3dd76b3d2967 100644
--- a/arch/mips/kernel/irq.c
+++ b/arch/mips/kernel/irq.c
@@ -68,9 +68,8 @@ 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))
-                                seq_printf(p, "CPU%d       ",j);
+                for_each_online_cpu(j)
+                        seq_printf(p, "CPU%d       ",j);
                 seq_putc(p, '\n');
         }
 
@@ -83,9 +82,8 @@ 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);
                 seq_printf(p, "  %s", action->name);
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index 06ed90752424..78d171bfa331 100644
--- a/arch/mips/kernel/smp.c
+++ b/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 */
diff --git a/arch/mips/sgi-ip27/ip27-irq.c b/arch/mips/sgi-ip27/ip27-irq.c
index 73e5e52781d8..2854ac4c9be1 100644
--- a/arch/mips/sgi-ip27/ip27-irq.c
+++ b/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;