tcp: md5: remove spinlock usage in fast path
TCP md5 code uses per cpu variables but protects access to them with
a shared spinlock, which is a contention point.
[ tcp_md5sig_pool_lock is locked twice per incoming packet ]
Makes things much simpler, by allocating crypto structures once, first
time a socket needs md5 keys, and not deallocating them as they are
really small.
Next step would be to allow crypto allocations being done in a NUMA
aware way.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index e1c3723..bf1cc3d 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1283,11 +1283,13 @@
#define tcp_twsk_md5_key(twsk) NULL
#endif
-extern struct tcp_md5sig_pool __percpu *tcp_alloc_md5sig_pool(struct sock *);
-extern void tcp_free_md5sig_pool(void);
+extern bool tcp_alloc_md5sig_pool(void);
extern struct tcp_md5sig_pool *tcp_get_md5sig_pool(void);
-extern void tcp_put_md5sig_pool(void);
+static inline void tcp_put_md5sig_pool(void)
+{
+ local_bh_enable();
+}
extern int tcp_md5_hash_header(struct tcp_md5sig_pool *, const struct tcphdr *);
extern int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *, const struct sk_buff *,