From da413eec729dae5dcb150e2eb34c5e7e5e4e1b49 Mon Sep 17 00:00:00 2001 From: Dan Collins Date: Fri, 19 Dec 2014 16:49:25 +1300 Subject: [PATCH] packet: Fixed TPACKET V3 to signal poll when block is closed rather than every packet Make TPACKET_V3 signal poll when block is closed rather than for every packet. Side effect is that poll will be signaled when block retire timer expires which didn't previously happen. Issue was visible when sending packets at a very low frequency such that all blocks are retired before packets are received by TPACKET_V3. This caused avoidable packet loss. The fix ensures that the signal is sent when blocks are closed which covers the normal path where the block is filled as well as the path where the timer expires. The case where a block is filled without moving to the next block (ie. all blocks are full) will still cause poll to be signaled. Signed-off-by: Dan Collins Signed-off-by: David S. Miller --- net/packet/af_packet.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index e52a44785681..6880f34a529a 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -785,6 +785,7 @@ static void prb_close_block(struct tpacket_kbdq_core *pkc1, struct tpacket3_hdr *last_pkt; struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; + struct sock *sk = &po->sk; if (po->stats.stats3.tp_drops) status |= TP_STATUS_LOSING; @@ -809,6 +810,8 @@ static void prb_close_block(struct tpacket_kbdq_core *pkc1, /* Flush the block */ prb_flush_block(pkc1, pbd1, status); + sk->sk_data_ready(sk); + pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); } @@ -2052,12 +2055,12 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, smp_wmb(); #endif - if (po->tp_version <= TPACKET_V2) + if (po->tp_version <= TPACKET_V2) { __packet_set_status(po, h.raw, status); - else + sk->sk_data_ready(sk); + } else { prb_clear_blk_fill_status(&po->rx_ring); - - sk->sk_data_ready(sk); + } drop_n_restore: if (skb_head != skb->data && skb_shared(skb)) {