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af_iucv: use paged SKBs for big inbound messages

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When an inbound message is bigger than a page, allocate a paged SKB,
and subsequently use IUCV receive primitive with IPBUFLST flag.
This relaxes the pressure to allocate big contiguous kernel buffers.

Signed-off-by: Eugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eugene Crosser 2016-06-13 18:46:16 +02:00 committed by David S. Miller
parent 291759a575
commit a006353a9a
1 changed files with 50 additions and 6 deletions
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56
net/iucv/af_iucv.c
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@ -1231,6 +1231,34 @@ out:
return err; return err;
} }
static struct sk_buff *alloc_iucv_recv_skb(unsigned long len)
{
size_t headroom, linear;
struct sk_buff *skb;
int err;
if (len < PAGE_SIZE) {
headroom = 0;
linear = len;
} else {
headroom = sizeof(struct iucv_array) * (MAX_SKB_FRAGS + 1);
linear = PAGE_SIZE - headroom;
}
skb = alloc_skb_with_frags(headroom + linear, len - linear,
0, &err, GFP_ATOMIC | GFP_DMA);
WARN_ONCE(!skb,
"alloc of recv iucv skb len=%lu failed with errcode=%d\n",
len, err);
if (skb) {
if (headroom)
skb_reserve(skb, headroom);
skb_put(skb, linear);
skb->len = len;
skb->data_len = len - linear;
}
return skb;
}
/* iucv_process_message() - Receive a single outstanding IUCV message /* iucv_process_message() - Receive a single outstanding IUCV message
* *
* Locking: must be called with message_q.lock held * Locking: must be called with message_q.lock held
@ -1255,16 +1283,32 @@ static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
skb->len = 0; skb->len = 0;
} }
} else { } else {
rc = pr_iucv->message_receive(path, msg, if (skb_is_nonlinear(skb)) {
struct iucv_array *iba = (struct iucv_array *)skb->head;
int i;
iba[0].address = (u32)(addr_t)skb->data;
iba[0].length = (u32)skb_headlen(skb);
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
iba[i + 1].address =
(u32)(addr_t)skb_frag_address(frag);
iba[i + 1].length = (u32)skb_frag_size(frag);
}
rc = pr_iucv->message_receive(path, msg,
IUCV_IPBUFLST,
(void *)iba, len, NULL);
} else {
rc = pr_iucv->message_receive(path, msg,
msg->flags & IUCV_IPRMDATA, msg->flags & IUCV_IPRMDATA,
skb->data, len, NULL); skb->data, len, NULL);
}
if (rc) { if (rc) {
kfree_skb(skb); kfree_skb(skb);
return; return;
} }
skb_reset_transport_header(skb); WARN_ON_ONCE(skb->len != len);
skb_reset_network_header(skb);
skb->len = len;
} }
IUCV_SKB_CB(skb)->offset = 0; IUCV_SKB_CB(skb)->offset = 0;
@ -1283,7 +1327,7 @@ static void iucv_process_message_q(struct sock *sk)
struct sock_msg_q *p, *n; struct sock_msg_q *p, *n;
list_for_each_entry_safe(p, n, &iucv->message_q.list, list) { list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
skb = alloc_skb(iucv_msg_length(&p->msg), GFP_ATOMIC | GFP_DMA); skb = alloc_iucv_recv_skb(iucv_msg_length(&p->msg));
if (!skb) if (!skb)
break; break;
iucv_process_message(sk, skb, p->path, &p->msg); iucv_process_message(sk, skb, p->path, &p->msg);
@ -1778,7 +1822,7 @@ static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
if (len > sk->sk_rcvbuf) if (len > sk->sk_rcvbuf)
goto save_message; goto save_message;
skb = alloc_skb(iucv_msg_length(msg), GFP_ATOMIC | GFP_DMA); skb = alloc_iucv_recv_skb(iucv_msg_length(msg));
if (!skb) if (!skb)
goto save_message; goto save_message;