Hi all: This series tries to switch to use skb array in tun. This is used to eliminate the spinlock contention between producer and consumer. The conversion was straightforward: just introdce a tx skb array and use it instead of sk_receive_queue.
A minor issue is to keep the tx_queue_len behaviour, since tun used to use it for the length of sk_receive_queue. This is done through: - add the ability to resize multiple rings at once to avoid handling partial resize failure for mutiple rings. - add the support for zero length ring. - introduce a notifier which was triggered when tx_queue_len was changed for a netdev. - resize all queues during the tx_queue_len changing. Tests shows about 15% improvement on guest rx pps: Before: ~1300000pps After : ~1500000pps Changes from V2: - add multiple rings resizing support for ptr_ring/skb_array - add zero length ring support - introdce a NETDEV_CHANGE_TX_QUEUE_LEN - drop new flags Changes from V1: - switch to use skb array instead of a customized circular buffer - add non-blocking support - rename .peek to .peek_len - drop lockless peeking since test show very minor improvement Jason Wang (5): ptr_ring: support zero length ring skb_array: minor tweak skb_array: add wrappers for resizing net: introduce NETDEV_CHANGE_TX_QUEUE_LEN tun: switch to use skb array for tx Michael S. Tsirkin (1): ptr_ring: support resizing multiple queues drivers/net/tun.c | 138 ++++++++++++++++++++++++++++++++++++--- drivers/vhost/net.c | 16 ++++- include/linux/net.h | 1 + include/linux/netdevice.h | 1 + include/linux/ptr_ring.h | 77 ++++++++++++++++++---- include/linux/skb_array.h | 13 +++- net/core/net-sysfs.c | 15 ++++- tools/virtio/ringtest/ptr_ring.c | 5 ++ 8 files changed, 243 insertions(+), 23 deletions(-) -- 2.7.4
