[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>

2 files changed, 4 insertions, 6 deletions

diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c
index 6883c00728cb..b56e79632f24 100644
--- a/arch/sh/kernel/irq.c
+++ b/arch/sh/kernel/irq.c
@@ -35,9 +35,8 @@ 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))
-                                seq_printf(p, "CPU%d       ",j);
+                for_each_online_cpu(j)
+                        seq_printf(p, "CPU%d       ",j);
                 seq_putc(p, '\n');
         }
 
diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c
index a067a34e0b64..c0e79843f580 100644
--- a/arch/sh/kernel/setup.c
+++ b/arch/sh/kernel/setup.c
@@ -404,9 +404,8 @@ static int __init topology_init(void)
 {
         int cpu_id;
 
-        for (cpu_id = 0; cpu_id < NR_CPUS; cpu_id++)
-                if (cpu_possible(cpu_id))
-                        register_cpu(&cpu[cpu_id], cpu_id, NULL);
+        for_each_cpu(cpu_id)
+                register_cpu(&cpu[cpu_id], cpu_id, NULL);
 
         return 0;
 }