Hi!
On 05.07.2017 19:00, Eric Dumazet wrote:
> From: Eric Dumazet <eduma...@google.com>
>
> As discussed in Faro during Netfilter Workshop 2017, RB trees can be
> used with RCU, using a seqlock.
>
> Note that net/rxrpc/conn_service.c is already using this.
>
> This patch converts inetpeer from AVL tree to RB tree, since it allows
> to remove private AVL code in favor of shared RB code.
>
> $ size net/ipv4/inetpeer.before net/ipv4/inetpeer.after
> text data bss dec hex filename
> 3195 40 128 3363 d23 net/ipv4/inetpeer.before
> 1562 24 0 1586 632 net/ipv4/inetpeer.after
>
> The same technique can be used to speed up
> net/netfilter/nft_set_rbtree.c
>
> Signed-off-by: Eric Dumazet <eduma...@google.com>
> ---
>
> return p;
> @@ -467,8 +231,9 @@ EXPORT_SYMBOL_GPL(inet_getpeer);
> void inet_putpeer(struct inet_peer *p)
> {
> p->dtime = (__u32)jiffies;
> - smp_mb__before_atomic();
> - refcount_dec(&p->refcnt);
> +
> + if (refcount_dec_and_test(&p->refcnt))
Missing rb_erase() here...
> + call_rcu(&p->rcu, inetpeer_free_rcu);
> }
> EXPORT_SYMBOL_GPL(inet_putpeer);
>
>
--Mika
