[PATCH net-next v3 01/13] sock: allocate skbs from optmem
From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Date: 2017-06-21 21:18:24
Also in:
linux-api
Subsystem:
networking [general], networking [sockets], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Linus Torvalds
From: Willem de Bruijn <willemb@google.com> Add sock_omalloc and sock_ofree to be able to allocate control skbs, for instance for looping errors onto sk_error_queue. The transmit budget (sk_wmem_alloc) is involved in transmit skb shaping, most notably in TCP Small Queues. Using this budget for control packets would impact transmission. Signed-off-by: Willem de Bruijn <willemb@google.com> --- include/net/sock.h | 2 ++ net/core/sock.c | 27 +++++++++++++++++++++++++++ 2 files changed, 29 insertions(+)
diff --git a/include/net/sock.h b/include/net/sock.h
index 00d09140e354..101247d63914 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h@@ -1527,6 +1527,8 @@ struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force, gfp_t priority); void __sock_wfree(struct sk_buff *skb); void sock_wfree(struct sk_buff *skb); +struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size, + gfp_t priority); void skb_orphan_partial(struct sk_buff *skb); void sock_rfree(struct sk_buff *skb); void sock_efree(struct sk_buff *skb);
diff --git a/net/core/sock.c b/net/core/sock.c
index 6f4b090241c1..34b5dcd93340 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c@@ -1923,6 +1923,33 @@ struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force, } EXPORT_SYMBOL(sock_wmalloc); +static void sock_ofree(struct sk_buff *skb) +{ + struct sock *sk = skb->sk; + + atomic_sub(skb->truesize, &sk->sk_omem_alloc); +} + +struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size, + gfp_t priority) +{ + struct sk_buff *skb; + + /* small safe race: SKB_TRUESIZE may differ from final skb->truesize */ + if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) > + sysctl_optmem_max) + return NULL; + + skb = alloc_skb(size, priority); + if (!skb) + return NULL; + + atomic_add(skb->truesize, &sk->sk_omem_alloc); + skb->sk = sk; + skb->destructor = sock_ofree; + return skb; +} + /* * Allocate a memory block from the socket's option memory buffer. */
--
2.13.1.611.g7e3b11ae1-goog