[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, 3 insertions, 4 deletions

diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
index 9044aeb37828..78cf45547e31 100644
--- a/include/asm-generic/percpu.h
+++ b/include/asm-generic/percpu.h
@@ -19,10 +19,9 @@ 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))                          \
-                        memcpy((pcpudst)+__per_cpu_offset[__i], \
-                               (src), (size));                  \
+        for_each_cpu(__i)                                       \
+                memcpy((pcpudst)+__per_cpu_offset[__i],         \
+                       (src), (size));                          \
 } while (0)
 #else /* ! SMP */