inetpeer: restore small inet_peer structures
Addition of rcu_head to struct inet_peer added 16bytes on 64bit arches.
Thats a bit unfortunate, since old size was exactly 64 bytes.
This can be solved, using an union between this rcu_head an four fields,
that are normally used only when a refcount is taken on inet_peer.
rcu_head is used only when refcnt=-1, right before structure freeing.
Add a inet_peer_refcheck() function to check this assertion for a while.
We can bring back SLAB_HWCACHE_ALIGN qualifier in kmem cache creation.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c
index 349249f..9ffa24b 100644
--- a/net/ipv4/inetpeer.c
+++ b/net/ipv4/inetpeer.c
@@ -64,7 +64,7 @@
* usually under some other lock to prevent node disappearing
* dtime: unused node list lock
* v4daddr: unchangeable
- * ip_id_count: idlock
+ * ip_id_count: atomic value (no lock needed)
*/
static struct kmem_cache *peer_cachep __read_mostly;
@@ -129,7 +129,7 @@
peer_cachep = kmem_cache_create("inet_peer_cache",
sizeof(struct inet_peer),
- 0, SLAB_PANIC,
+ 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
NULL);
/* All the timers, started at system startup tend
