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This will be useful to allow busy poll for tunneled traffic. In case of busy poll for sessions over tunnels, the underlying physical device's queues need to be polled. Tunnels schedule NAPI either via netif_rx() for backlog queue or schedule the gro_cell_poll(). netif_rx() propagates the valid skb->napi_id to the socket. OTOH, gro_cell_poll() stamps the skb->napi_id again by calling skb_mark_napi_id() with the tunnel NAPI which is not a busy poll candidate. This was preventing tunneled traffic to use busy poll. A valid NAPI ID in the skb indicates it was already marked for busy poll by a NAPI driver and hence needs to be copied into the socket. Signed-off-by: Amritha Nambiar <amritha.nambiar@intel.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
145 lines
3.3 KiB
C
145 lines
3.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* net busy poll support
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* Copyright(c) 2013 Intel Corporation.
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*
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* Author: Eliezer Tamir
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*
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* Contact Information:
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* e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
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*/
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#ifndef _LINUX_NET_BUSY_POLL_H
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#define _LINUX_NET_BUSY_POLL_H
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#include <linux/netdevice.h>
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#include <linux/sched/clock.h>
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#include <linux/sched/signal.h>
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#include <net/ip.h>
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/* 0 - Reserved to indicate value not set
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* 1..NR_CPUS - Reserved for sender_cpu
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* NR_CPUS+1..~0 - Region available for NAPI IDs
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*/
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#define MIN_NAPI_ID ((unsigned int)(NR_CPUS + 1))
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#ifdef CONFIG_NET_RX_BUSY_POLL
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struct napi_struct;
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extern unsigned int sysctl_net_busy_read __read_mostly;
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extern unsigned int sysctl_net_busy_poll __read_mostly;
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static inline bool net_busy_loop_on(void)
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{
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return sysctl_net_busy_poll;
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}
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static inline bool sk_can_busy_loop(const struct sock *sk)
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{
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return sk->sk_ll_usec && !signal_pending(current);
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}
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bool sk_busy_loop_end(void *p, unsigned long start_time);
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void napi_busy_loop(unsigned int napi_id,
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bool (*loop_end)(void *, unsigned long),
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void *loop_end_arg);
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#else /* CONFIG_NET_RX_BUSY_POLL */
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static inline unsigned long net_busy_loop_on(void)
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{
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return 0;
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}
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static inline bool sk_can_busy_loop(struct sock *sk)
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{
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return false;
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}
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#endif /* CONFIG_NET_RX_BUSY_POLL */
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static inline unsigned long busy_loop_current_time(void)
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{
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#ifdef CONFIG_NET_RX_BUSY_POLL
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return (unsigned long)(local_clock() >> 10);
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#else
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return 0;
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#endif
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}
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/* in poll/select we use the global sysctl_net_ll_poll value */
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static inline bool busy_loop_timeout(unsigned long start_time)
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{
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#ifdef CONFIG_NET_RX_BUSY_POLL
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unsigned long bp_usec = READ_ONCE(sysctl_net_busy_poll);
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if (bp_usec) {
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unsigned long end_time = start_time + bp_usec;
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unsigned long now = busy_loop_current_time();
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return time_after(now, end_time);
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}
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#endif
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return true;
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}
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static inline bool sk_busy_loop_timeout(struct sock *sk,
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unsigned long start_time)
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{
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#ifdef CONFIG_NET_RX_BUSY_POLL
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unsigned long bp_usec = READ_ONCE(sk->sk_ll_usec);
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if (bp_usec) {
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unsigned long end_time = start_time + bp_usec;
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unsigned long now = busy_loop_current_time();
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return time_after(now, end_time);
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}
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#endif
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return true;
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}
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static inline void sk_busy_loop(struct sock *sk, int nonblock)
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{
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#ifdef CONFIG_NET_RX_BUSY_POLL
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unsigned int napi_id = READ_ONCE(sk->sk_napi_id);
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if (napi_id >= MIN_NAPI_ID)
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napi_busy_loop(napi_id, nonblock ? NULL : sk_busy_loop_end, sk);
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#endif
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}
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/* used in the NIC receive handler to mark the skb */
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static inline void skb_mark_napi_id(struct sk_buff *skb,
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struct napi_struct *napi)
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{
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#ifdef CONFIG_NET_RX_BUSY_POLL
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/* If the skb was already marked with a valid NAPI ID, avoid overwriting
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* it.
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*/
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if (skb->napi_id < MIN_NAPI_ID)
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skb->napi_id = napi->napi_id;
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#endif
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}
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/* used in the protocol hanlder to propagate the napi_id to the socket */
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static inline void sk_mark_napi_id(struct sock *sk, const struct sk_buff *skb)
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{
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#ifdef CONFIG_NET_RX_BUSY_POLL
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WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
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#endif
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sk_rx_queue_set(sk, skb);
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}
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/* variant used for unconnected sockets */
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static inline void sk_mark_napi_id_once(struct sock *sk,
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const struct sk_buff *skb)
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{
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#ifdef CONFIG_NET_RX_BUSY_POLL
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if (!READ_ONCE(sk->sk_napi_id))
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WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
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#endif
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}
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#endif /* _LINUX_NET_BUSY_POLL_H */
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