Use existing sock refcnt debugging
Subsystems (4)
RFC PATCH 1/1 Use existing sock refcnt debugging
Hi, Arnaldo.
I've grep-ed through the code and found one more place, where the sk refcnt debugging is required, but is still performed in an old fashion - this is the LLC2.
The problem in using the sk_refcnt_debug_xxx here is that these socks do not provide the sk_destruct callback to catch the moment of the sock destruction.
Making this callback mandatory is not a good solution, as most often it will be empty and thus useless. Making this callback be set under the #ifdef SOCK_REFCNT_DEBUG is even more ugly than the previous one.
So, I propose to extend the sk_refcnt_debug_xxx set of helperf for those socks not having the sk_destruct callback by default, like the LLC2 ones.
The new helper is sk_refcnt_debug_inc_undo(sk) sets the sk_destruct callback into the sk_refcnt_debug_dec() in case the SOCK_REFCNT_DEBUG is on.
What do you think about it?
---
include/net/sock.h +11 -0
@@ -654,10 +654,21 @@ static inline void sk_refcnt_debug_release(const struct sock *sk)printk (KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n" , sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt)); } + +/* +* this one is to be used *only* for thouse socks, that +* do not have their own sk_destruct callback +*/ +static inline void sk_refcnt_debug_inc_undo (struct sock *sk) +{ +sk_refcnt_debug_inc (sk); + sk->sk_destruct = sk_refcnt_debug_dec; +}#else /* SOCK_REFCNT_DEBUG */ #define sk_refcnt_debug_inc (sk) do { } while (0)#define sk_refcnt_debug_dec (sk) do { } while (0)#define sk_refcnt_debug_release (sk) do { } while (0) +#define sk_refcnt_debug_inc_undo (sk) do { } while (0)#endif /* SOCK_REFCNT_DEBUG */ /* Called with local bh disabled */
net/llc/llc_conn.c +2 -22
@@ -775,11 +775,6 @@ drop_unlock: goto out; } -#undef LLC_REFCNT_DEBUG -#ifdef LLC_REFCNT_DEBUG -static atomic_t llc_sock_nr; -#endif -/** * llc_backlog_rcv - Processes rx frames and expired timers. * @sk: LLC sock (p8022 connection)
@@ -875,11 +870,7 @@ struct sock *llc_sk_alloc(struct net *net, int family, gfp_t priority, struct pr goto out;llc_sk_init (sk);sock_init_data (NULL , sk); -#ifdef LLC_REFCNT_DEBUG -atomic_inc (&llc_sock_nr); -printk (KERN_DEBUG "LLC socket %p created in %s, now we have %d alive\n" , sk, - __FUNCTION__,atomic_read (&llc_sock_nr)); -#endif +sk_refcnt_debug_inc_undo (sk); out:return sk; }
@@ -905,18 +896,7 @@ void llc_sk_free(struct sock *sk)skb_queue_purge (&sk->sk_receive_queue);skb_queue_purge (&sk->sk_write_queue);skb_queue_purge (&llc->pdu_unack_q); -#ifdef LLC_REFCNT_DEBUG -if (atomic_read (&sk->sk_refcnt) !=1 ) { -printk (KERN_DEBUG "Destruction of LLC sock %p delayed in %s, cnt=%d\n" , - sk, __FUNCTION__,atomic_read (&sk->sk_refcnt)); -printk (KERN_DEBUG "%d LLC sockets are still alive\n" , -atomic_read (&llc_sock_nr)); - }else { -atomic_dec (&llc_sock_nr); -printk (KERN_DEBUG "LLC socket %p released in %s, %d are still alive\n" , sk, - __FUNCTION__,atomic_read (&llc_sock_nr)); - } -#endif +sk_refcnt_debug_release (sk);sock_put (sk); }