Merge 'Linux v3.0' into Litmus

Some notes:
* Litmus^RT scheduling class is the topmost scheduling class
  (above stop_sched_class).
* scheduler_ipi() function (e.g., in smp_reschedule_interrupt())
  may increase IPI latencies.
* Added path into schedule() to quickly re-evaluate scheduling
  decision without becoming preemptive again. This used to be
  a standard path before the removal of BKL.

Conflicts:
	Makefile
	arch/arm/kernel/calls.S
	arch/arm/kernel/smp.c
	arch/x86/include/asm/unistd_32.h
	arch/x86/kernel/smp.c
	arch/x86/kernel/syscall_table_32.S
	include/linux/hrtimer.h
	kernel/printk.c
	kernel/sched.c
	kernel/sched_fair.c

1 files changed, 37 insertions, 14 deletions

diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 242879b6c4df..4014b623880c 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -91,26 +91,28 @@ struct neigh_statistics {
 #define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field)
 
 struct neighbour {
-        struct neighbour        *next;
+        struct neighbour __rcu  *next;
         struct neigh_table      *tbl;
         struct neigh_parms      *parms;
-        struct net_device               *dev;
-        unsigned long           used;
         unsigned long           confirmed;
         unsigned long           updated;
+        rwlock_t                lock;
+        atomic_t                refcnt;
+        struct sk_buff_head     arp_queue;
+        struct timer_list       timer;
+        unsigned long           used;
+        atomic_t                probes;
         __u8                    flags;
         __u8                    nud_state;
         __u8                    type;
         __u8                    dead;
-        atomic_t                probes;
-        rwlock_t                lock;
+        seqlock_t               ha_lock;
         unsigned char           ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];
         struct hh_cache         *hh;
-        atomic_t                refcnt;
         int                     (*output)(struct sk_buff *skb);
-        struct sk_buff_head     arp_queue;
-        struct timer_list       timer;
         const struct neigh_ops  *ops;
+        struct rcu_head         rcu;
+        struct net_device       *dev;
         u8                      primary_key[0];
 };
 
@@ -138,13 +140,22 @@ struct pneigh_entry {
  *      neighbour table manipulation
  */
 
+struct neigh_hash_table {
+        struct neighbour __rcu  **hash_buckets;
+        unsigned int            hash_mask;
+        __u32                   hash_rnd;
+        struct rcu_head         rcu;
+};
+
 
 struct neigh_table {
         struct neigh_table      *next;
         int                     family;
         int                     entry_size;
         int                     key_len;
-        __u32                   (*hash)(const void *pkey, const struct net_device *);
+        __u32                   (*hash)(const void *pkey,
+                                        const struct net_device *dev,
+                                        __u32 hash_rnd);
         int                     (*constructor)(struct neighbour *);
         int                     (*pconstructor)(struct pneigh_entry *);
         void                    (*pdestructor)(struct pneigh_entry *);
@@ -163,11 +174,9 @@ struct neigh_table {
         atomic_t                entries;
         rwlock_t                lock;
         unsigned long           last_rand;
-        struct kmem_cache               *kmem_cachep;
+        struct kmem_cache       *kmem_cachep;
         struct neigh_statistics __percpu *stats;
-        struct neighbour        **hash_buckets;
-        unsigned int            hash_mask;
-        __u32                   hash_rnd;
+        struct neigh_hash_table __rcu *nht;
         struct pneigh_entry     **phash_buckets;
 };
 
@@ -237,6 +246,7 @@ extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_en
 struct neigh_seq_state {
         struct seq_net_private p;
         struct neigh_table *tbl;
+        struct neigh_hash_table *nht;
         void *(*neigh_sub_iter)(struct neigh_seq_state *state,
                                 struct neighbour *n, loff_t *pos);
         unsigned int bucket;
@@ -293,7 +303,10 @@ static inline void neigh_confirm(struct neighbour *neigh)
 
 static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 {
-        neigh->used = jiffies;
+        unsigned long now = jiffies;
+        
+        if (neigh->used != now)
+                neigh->used = now;
         if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
                 return __neigh_event_send(neigh, skb);
         return 0;
@@ -364,4 +377,14 @@ struct neighbour_cb {
 
 #define NEIGH_CB(skb)   ((struct neighbour_cb *)(skb)->cb)
 
+static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
+                                     const struct net_device *dev)
+{
+        unsigned int seq;
+
+        do {
+                seq = read_seqbegin(&n->ha_lock);
+                memcpy(dst, n->ha, dev->addr_len);
+        } while (read_seqretry(&n->ha_lock, seq));
+}
 #endif