In inet_frag_find() unfortunate cache-line bounces can occur with
struct inet_frag_queue. As the net pointer (struct netns_frags)
is placed on the same write-often cache-line as e.g. refcnt and
lock. As the hash match check always check (q->net == nf).
This (of-cause) only happens on hash bucket collisions, but as current
hash size is only 64 this makes collisions more likely.
Signed-off-by: Jesper Dangaard Brouer <redacted>
---
include/net/inet_frag.h | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
index 7b897b2..1f75316 100644
--- a/include/net/inet_frag.h
+++ b/include/net/inet_frag.h
@@ -14,7 +14,6 @@ struct netns_frags {
struct inet_frag_queue {
struct hlist_node list;
- struct netns_frags *net;
struct list_head lru_list; /* lru list member */
spinlock_t lock;
atomic_t refcnt;@@ -24,6 +23,7 @@ struct inet_frag_queue {
ktime_t stamp;
int len; /* total length of orig datagram */
int meat;
+ struct netns_frags *net;
u32 creation_ts;/* jiffies when queue was created*/
__u8 last_in; /* first/last segment arrived? */