net: clean up snmp stats code

commit 8f0ea0fe3a036a47767f9c80e (snmp: reduce percpu needs by 50%)
reduced snmp array size to 1, so technically it doesn't have to be
an array any more. What's more, after the following commit:

	commit 933393f58fef9963eac61db8093689544e29a600
	Date:   Thu Dec 22 11:58:51 2011 -0600

	    percpu: Remove irqsafe_cpu_xxx variants

	    We simply say that regular this_cpu use must be safe regardless of
	    preemption and interrupt state.  That has no material change for x86
	    and s390 implementations of this_cpu operations.  However, arches that
	    do not provide their own implementation for this_cpu operations will
	    now get code generated that disables interrupts instead of preemption.

probably no arch wants to have SNMP_ARRAY_SZ == 2. At least after
almost 3 years, no one complains.

So, just convert the array to a single pointer and remove snmp_mib_init()
and snmp_mib_free() as well.

Cc: Christoph Lameter <cl@linux.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 6 deletions

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index c08fbd11ceff..e63f242ae03e 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -2783,21 +2783,19 @@ static struct notifier_block xfrm_dev_notifier = {
 static int __net_init xfrm_statistics_init(struct net *net)
 {
         int rv;
-
-        if (snmp_mib_init((void __percpu **)net->mib.xfrm_statistics,
-                          sizeof(struct linux_xfrm_mib),
-                          __alignof__(struct linux_xfrm_mib)) < 0)
+        net->mib.xfrm_statistics = alloc_percpu(struct linux_xfrm_mib);
+        if (!net->mib.xfrm_statistics)
                 return -ENOMEM;
         rv = xfrm_proc_init(net);
         if (rv < 0)
-                snmp_mib_free((void __percpu **)net->mib.xfrm_statistics);
+                free_percpu(net->mib.xfrm_statistics);
         return rv;
 }
 
 static void xfrm_statistics_fini(struct net *net)
 {
         xfrm_proc_fini(net);
-        snmp_mib_free((void __percpu **)net->mib.xfrm_statistics);
+        free_percpu(net->mib.xfrm_statistics);
 }
 #else
 static int __net_init xfrm_statistics_init(struct net *net)