[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, 2 insertions, 5 deletions

diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index 690a1aae0b34..0c13795dca38 100644
--- a/drivers/net/loopback.c
+++ b/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;
diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c
index 78193e4bbdb5..330d3869b41e 100644
--- a/drivers/oprofile/cpu_buffer.c
+++ b/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)