This patch series apply the following techniques to optimize nf_conncount performance. * Early exit for garbage collection In order to reduce gc time, we skip traversing the full list on every node when doing garbage collection, since it is enough to zap a couple of expired entries. * Split tree insertion and traversal When we have a very coarse grouping, e.g. by large subnets, zone id, etc, it is likely that we do not need to do tree rotation because we'll find a node where we can attach new entry. Based on this observation, we then make traversal lockless (tree protected by RCU), and add extra lock in the individual node to protect list insertion/deletion, thereby allowing parallel insert/delete in different tree nodes. * Add garbage collection worker Instead of doing all of garbage collection task in the packet forwarding path, we will schedule a garbage collection worker when the number of nodes that can be freed exceeds a threshold. This patch series has dependency on the following commmit in nf git tree. 21ba8847 ("netfilter: nf_conncount: Fix garbage collection with zones") Yi-Hung Wei (7): netfilter: nf_conncount: Early exit for garbage collection netfilter: nf_conncount: Switch to plain list netfilter: nf_conncount: Early exit in nf_conncount_lookup() and cleanup netfilter: nf_conncount: Move locking into count_tree() netfilter: nf_conncount: Split insert and traversal netfilter: nf_conncount: Add list lock and use RCU for init tree search netfilter: nf_conncount: Add garbage collection worker include/net/netfilter/nf_conntrack_count.h | 37 ++- net/netfilter/nf_conncount.c | 374 ++++++++++++++++++++++------- net/netfilter/nft_connlimit.c | 36 +-- 3 files changed, 332 insertions(+), 115 deletions(-) -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html