| Message ID | 1547719310-1007-1-git-send-email-laoar.shao@gmail.com |
|---|---|
| State | Changes Requested |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net-next] net: sock: do not set sk_cookie in sk_clone_lock() | expand |
On Thu, Jan 17, 2019 at 2:02 AM Yafang Shao <laoar.shao@gmail.com> wrote: > > The only call site of sk_clone_lock is in inet_csk_clone_lock, > and sk_cookie will be set there. > So we don't need to set sk_cookie in sk_clone_lock(). > That can save an atomic operation. > Patch is fine, although the wording of ' atomic operation' is a bit misleading. atomic_set or atomic_read are plain memory writes and reads. Real ' atomic and expensive' operations are the ones doing RMW operations (with lock semantic on SMP) Reviewed-by: Eric Dumazet <edumazet@google.com> > Signed-off-by: Yafang Shao <laoar.shao@gmail.com> > --- > net/core/sock.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/net/core/sock.c b/net/core/sock.c > index f00902c..21e2a84 100644 > --- a/net/core/sock.c > +++ b/net/core/sock.c > @@ -1726,7 +1726,6 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority) > newsk->sk_err_soft = 0; > newsk->sk_priority = 0; > newsk->sk_incoming_cpu = raw_smp_processor_id(); > - atomic64_set(&newsk->sk_cookie, 0); > if (likely(newsk->sk_net_refcnt)) > sock_inuse_add(sock_net(newsk), 1); > > -- > 1.8.3.1 >
On Fri, Jan 18, 2019 at 12:40 AM Eric Dumazet <edumazet@google.com> wrote: > > On Thu, Jan 17, 2019 at 2:02 AM Yafang Shao <laoar.shao@gmail.com> wrote: > > > > The only call site of sk_clone_lock is in inet_csk_clone_lock, > > and sk_cookie will be set there. > > So we don't need to set sk_cookie in sk_clone_lock(). > > That can save an atomic operation. > > > > Patch is fine, although the wording of ' atomic operation' is a bit misleading. > > atomic_set or atomic_read are plain memory writes and reads. > > Real ' atomic and expensive' operations are the ones doing RMW > operations (with lock semantic on SMP) > > Reviewed-by: Eric Dumazet <edumazet@google.com> > Thanks for your correction. Will change it and send v2. > > > Signed-off-by: Yafang Shao <laoar.shao@gmail.com> > > --- > > net/core/sock.c | 1 - > > 1 file changed, 1 deletion(-) > > > > diff --git a/net/core/sock.c b/net/core/sock.c > > index f00902c..21e2a84 100644 > > --- a/net/core/sock.c > > +++ b/net/core/sock.c > > @@ -1726,7 +1726,6 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority) > > newsk->sk_err_soft = 0; > > newsk->sk_priority = 0; > > newsk->sk_incoming_cpu = raw_smp_processor_id(); > > - atomic64_set(&newsk->sk_cookie, 0); > > if (likely(newsk->sk_net_refcnt)) > > sock_inuse_add(sock_net(newsk), 1); > > > > -- > > 1.8.3.1 > >
diff --git a/net/core/sock.c b/net/core/sock.c index f00902c..21e2a84 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1726,7 +1726,6 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority) newsk->sk_err_soft = 0; newsk->sk_priority = 0; newsk->sk_incoming_cpu = raw_smp_processor_id(); - atomic64_set(&newsk->sk_cookie, 0); if (likely(newsk->sk_net_refcnt)) sock_inuse_add(sock_net(newsk), 1);
The only call site of sk_clone_lock is in inet_csk_clone_lock, and sk_cookie will be set there. So we don't need to set sk_cookie in sk_clone_lock(). That can save an atomic operation. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> --- net/core/sock.c | 1 - 1 file changed, 1 deletion(-)