From e53743994e21d2458f0129d07b253d66f96f5742 Mon Sep 17 00:00:00 2001 From: Eugene Crosser Date: Mon, 13 Jun 2016 18:46:14 +0200 Subject: af_iucv: use paged SKBs for big outbound messages When an outbound message is bigger than a page, allocate and fill a paged SKB, and subsequently use IUCV send primitive with IPBUFLST flag. This relaxes the pressure to allocate big contiguous kernel buffers. Signed-off-by: Eugene Crosser Signed-off-by: Ursula Braun Signed-off-by: David S. Miller --- net/iucv/af_iucv.c | 124 +++++++++++++++++++++++++++++++++-------------------- 1 file changed, 77 insertions(+), 47 deletions(-) (limited to 'net/iucv') diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c index fc3598a922b0..38448d17c006 100644 --- a/net/iucv/af_iucv.c +++ b/net/iucv/af_iucv.c @@ -1033,6 +1033,7 @@ static int iucv_sock_sendmsg(struct socket *sock, struct msghdr *msg, { struct sock *sk = sock->sk; struct iucv_sock *iucv = iucv_sk(sk); + size_t headroom, linear; struct sk_buff *skb; struct iucv_message txmsg = {0}; struct cmsghdr *cmsg; @@ -1110,20 +1111,31 @@ static int iucv_sock_sendmsg(struct socket *sock, struct msghdr *msg, * this is fine for SOCK_SEQPACKET (unless we want to support * segmented records using the MSG_EOR flag), but * for SOCK_STREAM we might want to improve it in future */ - if (iucv->transport == AF_IUCV_TRANS_HIPER) - skb = sock_alloc_send_skb(sk, - len + sizeof(struct af_iucv_trans_hdr) + ETH_HLEN, - noblock, &err); - else - skb = sock_alloc_send_skb(sk, len, noblock, &err); + headroom = (iucv->transport == AF_IUCV_TRANS_HIPER) + ? sizeof(struct af_iucv_trans_hdr) + ETH_HLEN : 0; + if (headroom + len < PAGE_SIZE) { + linear = len; + } else { + /* In nonlinear "classic" iucv skb, + * reserve space for iucv_array + */ + if (iucv->transport != AF_IUCV_TRANS_HIPER) + headroom += sizeof(struct iucv_array) * + (MAX_SKB_FRAGS + 1); + linear = PAGE_SIZE - headroom; + } + skb = sock_alloc_send_pskb(sk, headroom + linear, len - linear, + noblock, &err, 0); if (!skb) goto out; - if (iucv->transport == AF_IUCV_TRANS_HIPER) - skb_reserve(skb, sizeof(struct af_iucv_trans_hdr) + ETH_HLEN); - if (memcpy_from_msg(skb_put(skb, len), msg, len)) { - err = -EFAULT; + if (headroom) + skb_reserve(skb, headroom); + skb_put(skb, linear); + skb->len = len; + skb->data_len = len - linear; + err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, len); + if (err) goto fail; - } /* wait if outstanding messages for iucv path has reached */ timeo = sock_sndtimeo(sk, noblock); @@ -1148,49 +1160,67 @@ static int iucv_sock_sendmsg(struct socket *sock, struct msghdr *msg, atomic_dec(&iucv->msg_sent); goto fail; } - goto release; - } - skb_queue_tail(&iucv->send_skb_q, skb); - - if (((iucv->path->flags & IUCV_IPRMDATA) & iucv->flags) - && skb->len <= 7) { - err = iucv_send_iprm(iucv->path, &txmsg, skb); + } else { /* Classic VM IUCV transport */ + skb_queue_tail(&iucv->send_skb_q, skb); + + if (((iucv->path->flags & IUCV_IPRMDATA) & iucv->flags) && + skb->len <= 7) { + err = iucv_send_iprm(iucv->path, &txmsg, skb); + + /* on success: there is no message_complete callback */ + /* for an IPRMDATA msg; remove skb from send queue */ + if (err == 0) { + skb_unlink(skb, &iucv->send_skb_q); + kfree_skb(skb); + } - /* on success: there is no message_complete callback - * for an IPRMDATA msg; remove skb from send queue */ - if (err == 0) { - skb_unlink(skb, &iucv->send_skb_q); - kfree_skb(skb); + /* this error should never happen since the */ + /* IUCV_IPRMDATA path flag is set... sever path */ + if (err == 0x15) { + pr_iucv->path_sever(iucv->path, NULL); + skb_unlink(skb, &iucv->send_skb_q); + err = -EPIPE; + goto fail; + } + } else if (skb_is_nonlinear(skb)) { + struct iucv_array *iba = (struct iucv_array *)skb->head; + int i; + + /* skip iucv_array lying in the headroom */ + 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); + } + err = pr_iucv->message_send(iucv->path, &txmsg, + IUCV_IPBUFLST, 0, + (void *)iba, skb->len); + } else { /* non-IPRM Linear skb */ + err = pr_iucv->message_send(iucv->path, &txmsg, + 0, 0, (void *)skb->data, skb->len); } - - /* this error should never happen since the - * IUCV_IPRMDATA path flag is set... sever path */ - if (err == 0x15) { - pr_iucv->path_sever(iucv->path, NULL); + if (err) { + if (err == 3) { + user_id[8] = 0; + memcpy(user_id, iucv->dst_user_id, 8); + appl_id[8] = 0; + memcpy(appl_id, iucv->dst_name, 8); + pr_err( + "Application %s on z/VM guest %s exceeds message limit\n", + appl_id, user_id); + err = -EAGAIN; + } else { + err = -EPIPE; + } skb_unlink(skb, &iucv->send_skb_q); - err = -EPIPE; goto fail; } - } else - err = pr_iucv->message_send(iucv->path, &txmsg, 0, 0, - (void *) skb->data, skb->len); - if (err) { - if (err == 3) { - user_id[8] = 0; - memcpy(user_id, iucv->dst_user_id, 8); - appl_id[8] = 0; - memcpy(appl_id, iucv->dst_name, 8); - pr_err("Application %s on z/VM guest %s" - " exceeds message limit\n", - appl_id, user_id); - err = -EAGAIN; - } else - err = -EPIPE; - skb_unlink(skb, &iucv->send_skb_q); - goto fail; } -release: release_sock(sk); return len; -- cgit v1.2.3-59-g8ed1b From 291759a57532b7940b6e52c54ceebd6b8d9e113e Mon Sep 17 00:00:00 2001 From: Eugene Crosser Date: Mon, 13 Jun 2016 18:46:15 +0200 Subject: af_iucv: remove fragment_skb() to use paged SKBs Before introducing paged skbs in the receive path, get rid of the function `iucv_fragment_skb()` that replaces one large linear skb with several smaller linear skbs. Signed-off-by: Eugene Crosser Signed-off-by: Ursula Braun Signed-off-by: David S. Miller --- net/iucv/af_iucv.c | 59 +++--------------------------------------------------- 1 file changed, 3 insertions(+), 56 deletions(-) (limited to 'net/iucv') diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c index 38448d17c006..9ed2adf9e057 100644 --- a/net/iucv/af_iucv.c +++ b/net/iucv/af_iucv.c @@ -1231,44 +1231,6 @@ out: return err; } -/* iucv_fragment_skb() - Fragment a single IUCV message into multiple skb's - * - * Locking: must be called with message_q.lock held - */ -static int iucv_fragment_skb(struct sock *sk, struct sk_buff *skb, int len) -{ - int dataleft, size, copied = 0; - struct sk_buff *nskb; - - dataleft = len; - while (dataleft) { - if (dataleft >= sk->sk_rcvbuf / 4) - size = sk->sk_rcvbuf / 4; - else - size = dataleft; - - nskb = alloc_skb(size, GFP_ATOMIC | GFP_DMA); - if (!nskb) - return -ENOMEM; - - /* copy target class to control buffer of new skb */ - IUCV_SKB_CB(nskb)->class = IUCV_SKB_CB(skb)->class; - - /* copy data fragment */ - memcpy(nskb->data, skb->data + copied, size); - copied += size; - dataleft -= size; - - skb_reset_transport_header(nskb); - skb_reset_network_header(nskb); - nskb->len = size; - - skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, nskb); - } - - return 0; -} - /* iucv_process_message() - Receive a single outstanding IUCV message * * Locking: must be called with message_q.lock held @@ -1300,24 +1262,9 @@ static void iucv_process_message(struct sock *sk, struct sk_buff *skb, kfree_skb(skb); return; } - /* we need to fragment iucv messages for SOCK_STREAM only; - * for SOCK_SEQPACKET, it is only relevant if we support - * record segmentation using MSG_EOR (see also recvmsg()) */ - if (sk->sk_type == SOCK_STREAM && - skb->truesize >= sk->sk_rcvbuf / 4) { - rc = iucv_fragment_skb(sk, skb, len); - kfree_skb(skb); - skb = NULL; - if (rc) { - pr_iucv->path_sever(path, NULL); - return; - } - skb = skb_dequeue(&iucv_sk(sk)->backlog_skb_q); - } else { - skb_reset_transport_header(skb); - skb_reset_network_header(skb); - skb->len = len; - } + skb_reset_transport_header(skb); + skb_reset_network_header(skb); + skb->len = len; } IUCV_SKB_CB(skb)->offset = 0; -- cgit v1.2.3-59-g8ed1b From a006353a9a8d9e28d35f94bfc97e9573d6ee28aa Mon Sep 17 00:00:00 2001 From: Eugene Crosser Date: Mon, 13 Jun 2016 18:46:16 +0200 Subject: 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 Signed-off-by: Ursula Braun Signed-off-by: David S. Miller --- net/iucv/af_iucv.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 50 insertions(+), 6 deletions(-) (limited to 'net/iucv') diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c index 9ed2adf9e057..37d674e6f8a9 100644 --- a/net/iucv/af_iucv.c +++ b/net/iucv/af_iucv.c @@ -1231,6 +1231,34 @@ out: 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 @@ static void iucv_process_message(struct sock *sk, struct sk_buff *skb, 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 @@ 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; -- cgit v1.2.3-59-g8ed1b