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Commit a006353a authored by Eugene Crosser's avatar Eugene Crosser Committed by David S. Miller
Browse files

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: default avatarEugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: default avatarUrsula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 291759a5

net/iucv/af_iucv.c

+50 −6
Original line number Diff line number Diff line
@@ -1231,6 +1231,34 @@ static int iucv_sock_sendmsg(struct socket *sock, struct msghdr *msg, 
	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
@@ -1254,17 +1282,33 @@ static void iucv_process_message(struct sock *sk, struct sk_buff *skb, 
			skb->data = NULL;

			skb->len = 0;

		}

	} else {

		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 @@ static void iucv_process_message_q(struct sock *sk) 
	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 @@ static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg) 
	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;