af_iucv: use paged SKBs for big inbound messages
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>
diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index 9ed2adf..37d674e 100644
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -1231,6 +1231,34 @@
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
*
* Locking: must be called with message_q.lock held
@@ -1255,16 +1283,32 @@
skb->len = 0;
}
} 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,
skb->data, len, NULL);
+ }
if (rc) {
kfree_skb(skb);
return;
}
- skb_reset_transport_header(skb);
- skb_reset_network_header(skb);
- skb->len = len;
+ WARN_ON_ONCE(skb->len != len);
}
IUCV_SKB_CB(skb)->offset = 0;
@@ -1283,7 +1327,7 @@
struct sock_msg_q *p, *n;
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)
break;
iucv_process_message(sk, skb, p->path, &p->msg);
@@ -1778,7 +1822,7 @@
if (len > sk->sk_rcvbuf)
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)
goto save_message;