From 9073fb8be3ee6f89492b8ea8f6d3902913a9fc91 Mon Sep 17 00:00:00 2001 From: Jon Paul Maloy Date: Thu, 30 Jul 2015 18:24:25 -0400 Subject: [PATCH] tipc: use temporary, non-protected skb queue for bundle reception Currently, when we extract small messages from a message bundle, or when many messages have accumulated in the link arrival queue, those messages are added one by one to the lock protected link input queue. This may increase contention with the reader of that queue, in the function tipc_sk_rcv(). This commit introduces a temporary, unprotected input queue in tipc_link_rcv() for such cases. Only when the arrival queue has been emptied, and the function is ready to return, does it splice the whole temporary queue into the real input queue. Tested-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/link.c | 34 +++++++++++++++++++--------------- 1 file changed, 19 insertions(+), 15 deletions(-) diff --git a/net/tipc/link.c b/net/tipc/link.c index 2aa19de715f6..d683fe9f68c8 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -111,8 +111,6 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe, static void link_reset_statistics(struct tipc_link *l_ptr); static void link_print(struct tipc_link *l_ptr, const char *str); static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf); -static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb); -static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb); /* * Simple non-static link routines (i.e. referenced outside this file) @@ -960,18 +958,18 @@ static int tipc_link_retransm(struct tipc_link *l, int retransm, * Consumes buffer if message is of right type * Node lock must be held */ -static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb) +static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb, + struct sk_buff_head *inputq) { struct tipc_node *node = link->owner; - struct tipc_msg *msg = buf_msg(skb); - switch (msg_user(msg)) { + switch (msg_user(buf_msg(skb))) { case TIPC_LOW_IMPORTANCE: case TIPC_MEDIUM_IMPORTANCE: case TIPC_HIGH_IMPORTANCE: case TIPC_CRITICAL_IMPORTANCE: case CONN_MANAGER: - skb_queue_tail(link->inputq, skb); + __skb_queue_tail(inputq, skb); return true; case NAME_DISTRIBUTOR: node->bclink.recv_permitted = true; @@ -993,7 +991,8 @@ static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb) * * Consumes buffer */ -static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb) +static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb, + struct sk_buff_head *inputq) { struct tipc_node *node = l->owner; struct tipc_msg *hdr = buf_msg(skb); @@ -1016,7 +1015,7 @@ static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb) hdr = buf_msg(skb); if (less(msg_seqno(hdr), l->drop_point)) goto drop; - if (tipc_data_input(l, skb)) + if (tipc_data_input(l, skb, inputq)) return rc; usr = msg_user(hdr); reasm_skb = &l->failover_reasm_skb; @@ -1026,13 +1025,13 @@ static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb) l->stats.recv_bundles++; l->stats.recv_bundled += msg_msgcnt(hdr); while (tipc_msg_extract(skb, &iskb, &pos)) - tipc_data_input(l, iskb); + tipc_data_input(l, iskb, inputq); return 0; } else if (usr == MSG_FRAGMENTER) { l->stats.recv_fragments++; if (tipc_buf_append(reasm_skb, &skb)) { l->stats.recv_fragmented++; - tipc_data_input(l, skb); + tipc_data_input(l, skb, inputq); } else if (!*reasm_skb) { return tipc_link_fsm_evt(l, LINK_FAILURE_EVT); } @@ -1070,10 +1069,13 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb, struct sk_buff_head *xmitq) { struct sk_buff_head *arrvq = &l->deferdq; + struct sk_buff_head tmpq; struct tipc_msg *hdr; u16 seqno, rcv_nxt; int rc = 0; + __skb_queue_head_init(&tmpq); + if (unlikely(!__tipc_skb_queue_sorted(arrvq, skb))) { if (!(skb_queue_len(arrvq) % TIPC_NACK_INTV)) tipc_link_build_proto_msg(l, STATE_MSG, 0, @@ -1095,7 +1097,7 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb, rc = tipc_link_fsm_evt(l, LINK_ESTABLISH_EVT); if (!link_is_up(l)) { kfree_skb(__skb_dequeue(arrvq)); - return rc; + goto exit; } } @@ -1113,7 +1115,7 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb, rcv_nxt = l->rcv_nxt; if (unlikely(less(rcv_nxt, seqno))) { l->stats.deferred_recv++; - return rc; + goto exit; } __skb_dequeue(arrvq); @@ -1122,14 +1124,14 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb, if (unlikely(more(rcv_nxt, seqno))) { l->stats.duplicates++; kfree_skb(skb); - return rc; + goto exit; } /* Packet can be delivered */ l->rcv_nxt++; l->stats.recv_info++; - if (unlikely(!tipc_data_input(l, skb))) - rc = tipc_link_input(l, skb); + if (unlikely(!tipc_data_input(l, skb, &tmpq))) + rc = tipc_link_input(l, skb, &tmpq); /* Ack at regular intervals */ if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN)) { @@ -1139,6 +1141,8 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb, 0, 0, 0, 0, xmitq); } } +exit: + tipc_skb_queue_splice_tail(&tmpq, l->inputq); return rc; } -- 2.39.5