On Tue, Feb 14, 2023 at 1:30 AM Kuniyuki Iwashima <kuniyu@xxxxxxxxxx> wrote:
>
> From: Jason Xing <kerneljasonxing@xxxxxxxxx>
> Date: Sat, 11 Feb 2023 14:51:53 +0800
> > From: Jason Xing <kernelxing@xxxxxxxxxxx>
> >
> > Since commit 463c84b97f24 ("[NET]: Introduce inet_connection_sock")
> > commented out the definition of SOCK_REFCNT_DEBUG and later another
> > patch deleted it,
>
> e48c414ee61f ("[INET]: Generalise the TCP sock ID lookup routines")
> is the commit which commented out SOCK_REFCNT_DEBUG, and 463c84b97f24
> removed it.
Yes.
>
>
> > we need to enable it through defining it manually
> > somewhere. Wrapping it into an option in Kconfig.debug could make
> > it much clearer and easier for some developers to do things based
> > on this change.
>
> Considering SOCK_REFCNT_DEBUG is removed in 2005, how about removing
> the whole feature? I think we can track the same info easily with
> bpftrace + kprobe.
I agree with you since it seems no one is developing more features
based on it. I just did check every caller which may call those debug
interfaces and now confirm we surely can use bpf/kprobe related tools
to track. So I decided to remove the whole feature in the next
submission.
Thanks,
Jason
>
>
> >
> > Signed-off-by: Jason Xing <kernelxing@xxxxxxxxxxx>
> > ---
> > include/net/sock.h | 8 ++++----
> > net/Kconfig.debug | 8 ++++++++
> > net/ipv4/inet_timewait_sock.c | 2 +-
> > 3 files changed, 13 insertions(+), 5 deletions(-)
> >
> > diff --git a/include/net/sock.h b/include/net/sock.h
> > index dcd72e6285b2..1b001efeb9b5 100644
> > --- a/include/net/sock.h
> > +++ b/include/net/sock.h
> > @@ -1349,7 +1349,7 @@ struct proto {
> > char name[32];
> >
> > struct list_head node;
> > -#ifdef SOCK_REFCNT_DEBUG
> > +#ifdef CONFIG_SOCK_REFCNT_DEBUG
> > atomic_t socks;
> > #endif
> > int (*diag_destroy)(struct sock *sk, int err);
> > @@ -1359,7 +1359,7 @@ int proto_register(struct proto *prot, int alloc_slab);
> > void proto_unregister(struct proto *prot);
> > int sock_load_diag_module(int family, int protocol);
> >
> > -#ifdef SOCK_REFCNT_DEBUG
> > +#ifdef CONFIG_SOCK_REFCNT_DEBUG
> > static inline void sk_refcnt_debug_inc(struct sock *sk)
> > {
> > atomic_inc(&sk->sk_prot->socks);
> > @@ -1378,11 +1378,11 @@ 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, refcount_read(&sk->sk_refcnt));
> > }
> > -#else /* SOCK_REFCNT_DEBUG */
> > +#else /* CONFIG_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)
> > -#endif /* SOCK_REFCNT_DEBUG */
> > +#endif /* CONFIG_SOCK_REFCNT_DEBUG */
> >
> > INDIRECT_CALLABLE_DECLARE(bool tcp_stream_memory_free(const struct sock *sk, int wake));
> >
> > diff --git a/net/Kconfig.debug b/net/Kconfig.debug
> > index 5e3fffe707dd..667396d70e10 100644
> > --- a/net/Kconfig.debug
> > +++ b/net/Kconfig.debug
> > @@ -18,6 +18,14 @@ config NET_NS_REFCNT_TRACKER
> > Enable debugging feature to track netns references.
> > This adds memory and cpu costs.
> >
> > +config SOCK_REFCNT_DEBUG
> > + bool "Enable socket refcount debug"
> > + depends on DEBUG_KERNEL && NET
> > + default n
> > + help
> > + Enable debugging feature to track socket references.
> > + This adds memory and cpu costs.
> > +
> > config DEBUG_NET
> > bool "Add generic networking debug"
> > depends on DEBUG_KERNEL && NET
> > diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c
> > index beed32fff484..e313516b64ce 100644
> > --- a/net/ipv4/inet_timewait_sock.c
> > +++ b/net/ipv4/inet_timewait_sock.c
> > @@ -77,7 +77,7 @@ void inet_twsk_free(struct inet_timewait_sock *tw)
> > {
> > struct module *owner = tw->tw_prot->owner;
> > twsk_destructor((struct sock *)tw);
> > -#ifdef SOCK_REFCNT_DEBUG
> > +#ifdef CONFIG_SOCK_REFCNT_DEBUG
> > pr_debug("%s timewait_sock %p released\n", tw->tw_prot->name, tw);
> > #endif
> > kmem_cache_free(tw->tw_prot->twsk_prot->twsk_slab, tw);
> > --
> > 2.37.3
