From c463ac972315a0c86bb20b8d35225baa75caf899 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 9 Jun 2010 18:07:06 +0200 Subject: [PATCH] netfilter: nfnetlink_queue: some optimizations - Use an atomic_t for id_sequence to avoid a spin_lock/spin_unlock pair - Group highly modified struct nfqnl_instance fields together Signed-off-by: Eric Dumazet Signed-off-by: Patrick McHardy --- net/netfilter/nfnetlink_queue.c | 33 ++++++++++++++------------------- 1 file changed, 14 insertions(+), 19 deletions(-) diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index 12e1ab37fcd..d05605b38f6 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -46,17 +46,19 @@ struct nfqnl_instance { int peer_pid; unsigned int queue_maxlen; unsigned int copy_range; - unsigned int queue_total; unsigned int queue_dropped; unsigned int queue_user_dropped; - unsigned int id_sequence; /* 'sequence' of pkt ids */ u_int16_t queue_num; /* number of this queue */ u_int8_t copy_mode; - - spinlock_t lock; - +/* + * Following fields are dirtied for each queued packet, + * keep them in same cache line if possible. + */ + spinlock_t lock; + unsigned int queue_total; + atomic_t id_sequence; /* 'sequence' of pkt ids */ struct list_head queue_list; /* packets in queue */ }; @@ -238,32 +240,24 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue, outdev = entry->outdev; - spin_lock_bh(&queue->lock); - - switch ((enum nfqnl_config_mode)queue->copy_mode) { + switch ((enum nfqnl_config_mode)ACCESS_ONCE(queue->copy_mode)) { case NFQNL_COPY_META: case NFQNL_COPY_NONE: break; case NFQNL_COPY_PACKET: if (entskb->ip_summed == CHECKSUM_PARTIAL && - skb_checksum_help(entskb)) { - spin_unlock_bh(&queue->lock); + skb_checksum_help(entskb)) return NULL; - } - if (queue->copy_range == 0 - || queue->copy_range > entskb->len) + + data_len = ACCESS_ONCE(queue->copy_range); + if (data_len == 0 || data_len > entskb->len) data_len = entskb->len; - else - data_len = queue->copy_range; size += nla_total_size(data_len); break; } - entry->id = queue->id_sequence++; - - spin_unlock_bh(&queue->lock); skb = alloc_skb(size, GFP_ATOMIC); if (!skb) @@ -278,6 +272,7 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue, nfmsg->version = NFNETLINK_V0; nfmsg->res_id = htons(queue->queue_num); + entry->id = atomic_inc_return(&queue->id_sequence); pmsg.packet_id = htonl(entry->id); pmsg.hw_protocol = entskb->protocol; pmsg.hook = entry->hook; @@ -866,7 +861,7 @@ static int seq_show(struct seq_file *s, void *v) inst->peer_pid, inst->queue_total, inst->copy_mode, inst->copy_range, inst->queue_dropped, inst->queue_user_dropped, - inst->id_sequence, 1); + atomic_read(&inst->id_sequence), 1); } static const struct seq_operations nfqnl_seq_ops = { -- 2.11.4.GIT