diff options
| author |   Willem de Bruijn <willemb@google.com> | 2017-08-03 16:29:37 -0400 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2017-08-03 21:37:29 -0700 |
| commit | 98ba0bd5505dcbb90322a4be07bcfe6b8a18c73f (patch) | |
| tree | e9c2bbb059a118f41a5acf90e2a349ab704d8863 /net/core/sock.c | |
| parent | Merge branch 'mlxsw-Support-for-IPv6-UC-router' (diff) | |
| download | linux-dev-98ba0bd5505dcbb90322a4be07bcfe6b8a18c73f.tar.xz linux-dev-98ba0bd5505dcbb90322a4be07bcfe6b8a18c73f.zip | |
sock: allocate skbs from optmem
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/sock.c')
| -rw-r--r-- | net/core/sock.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/net/core/sock.c b/net/core/sock.c index 742f68c9c84a..1261880bdcc8 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. */ |