diff options
Diffstat (limited to 'include/net')
| -rw-r--r-- | include/net/ll_poll.h | 148 | ||||
| -rw-r--r-- | include/net/sock.h | 4 |
2 files changed, 152 insertions, 0 deletions
diff --git a/include/net/ll_poll.h b/include/net/ll_poll.h new file mode 100644 index 000000000000..bc262f88173f --- /dev/null +++ b/include/net/ll_poll.h @@ -0,0 +1,148 @@ +/* + * Low Latency Sockets + * Copyright(c) 2013 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. + * + * Author: Eliezer Tamir + * + * Contact Information: + * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net> + */ + +/* + * For now this depends on CONFIG_X86_TSC + */ + +#ifndef _LINUX_NET_LL_POLL_H +#define _LINUX_NET_LL_POLL_H + +#include <linux/netdevice.h> +#include <net/ip.h> + +#ifdef CONFIG_NET_LL_RX_POLL + +struct napi_struct; +extern unsigned long sysctl_net_ll_poll __read_mostly; + +/* return values from ndo_ll_poll */ +#define LL_FLUSH_FAILED -1 +#define LL_FLUSH_BUSY -2 + +/* we don't mind a ~2.5% imprecision */ +#define TSC_MHZ (tsc_khz >> 10) + +static inline cycles_t ll_end_time(void) +{ + return TSC_MHZ * ACCESS_ONCE(sysctl_net_ll_poll) + get_cycles(); +} + +static inline bool sk_valid_ll(struct sock *sk) +{ + return sysctl_net_ll_poll && sk->sk_napi_id && + !need_resched() && !signal_pending(current); +} + +static inline bool can_poll_ll(cycles_t end_time) +{ + return !time_after((unsigned long)get_cycles(), + (unsigned long)end_time); +} + +static inline bool sk_poll_ll(struct sock *sk, int nonblock) +{ + cycles_t end_time = ll_end_time(); + const struct net_device_ops *ops; + struct napi_struct *napi; + int rc = false; + + /* + * rcu read lock for napi hash + * bh so we don't race with net_rx_action + */ + rcu_read_lock_bh(); + + napi = napi_by_id(sk->sk_napi_id); + if (!napi) + goto out; + + ops = napi->dev->netdev_ops; + if (!ops->ndo_ll_poll) + goto out; + + do { + + rc = ops->ndo_ll_poll(napi); + + if (rc == LL_FLUSH_FAILED) + break; /* permanent failure */ + + if (rc > 0) + /* local bh are disabled so it is ok to use _BH */ + NET_ADD_STATS_BH(sock_net(sk), + LINUX_MIB_LOWLATENCYRXPACKETS, rc); + + } while (skb_queue_empty(&sk->sk_receive_queue) + && can_poll_ll(end_time) && !nonblock); + + rc = !skb_queue_empty(&sk->sk_receive_queue); +out: + rcu_read_unlock_bh(); + return rc; +} + +/* used in the NIC receive handler to mark the skb */ +static inline void skb_mark_ll(struct sk_buff *skb, struct napi_struct *napi) +{ + skb->napi_id = napi->napi_id; +} + +/* used in the protocol hanlder to propagate the napi_id to the socket */ +static inline void sk_mark_ll(struct sock *sk, struct sk_buff *skb) +{ + sk->sk_napi_id = skb->napi_id; +} + +#else /* CONFIG_NET_LL_RX_POLL */ + +static inline cycles_t ll_end_time(void) +{ + return 0; +} + +static inline bool sk_valid_ll(struct sock *sk) +{ + return false; +} + +static inline bool sk_poll_ll(struct sock *sk, int nonblock) +{ + return false; +} + +static inline void skb_mark_ll(struct sk_buff *skb, struct napi_struct *napi) +{ +} + +static inline void sk_mark_ll(struct sock *sk, struct sk_buff *skb) +{ +} + +static inline bool can_poll_ll(cycles_t end_time) +{ + return false; +} + +#endif /* CONFIG_NET_LL_RX_POLL */ +#endif /* _LINUX_NET_LL_POLL_H */ diff --git a/include/net/sock.h b/include/net/sock.h index 66772cf8c3c5..ac8e1818380c 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -229,6 +229,7 @@ struct cg_proto; * @sk_omem_alloc: "o" is "option" or "other" * @sk_wmem_queued: persistent queue size * @sk_forward_alloc: space allocated forward + * @sk_napi_id: id of the last napi context to receive data for sk * @sk_allocation: allocation mode * @sk_sndbuf: size of send buffer in bytes * @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE, @@ -325,6 +326,9 @@ struct sock { #ifdef CONFIG_RPS __u32 sk_rxhash; #endif +#ifdef CONFIG_NET_LL_RX_POLL + unsigned int sk_napi_id; +#endif atomic_t sk_drops; int sk_rcvbuf; |
