[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>

1 files changed, 4 insertions, 6 deletions

diff --git a/arch/ppc/kernel/setup.c b/arch/ppc/kernel/setup.c
index c08ab432e958..53e9deacee82 100644
--- a/arch/ppc/kernel/setup.c
+++ b/arch/ppc/kernel/setup.c
@@ -168,9 +168,8 @@ 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))
-                                bogosum += cpu_data[i].loops_per_jiffy;
+                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);
 #endif /* CONFIG_SMP */
@@ -712,9 +711,8 @@ 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))
-                        register_cpu(&cpu_devices[i], i, NULL);
+        for_each_cpu(i)
+                register_cpu(&cpu_devices[i], i, NULL);
 
         /* call platform init */
         if (ppc_md.init != NULL) {