Homa

homa_impl.h

 /* SPDX-License-Identifier: BSD-2-Clause */
 
 /* This file contains definitions that are shared across the files
  * that implement Homa for Linux.
  */
 
 #ifndef _HOMA_IMPL_H
 #define _HOMA_IMPL_H
 
 #include <linux/bug.h>
@@ skipping 526 matching lines @@
 
         /**
          * @max_dead_buffs: The largest aggregate number of packet buffers
          * in dead (but not yet reaped) RPCs that has existed so far in a
          * single socket.  Readable via sysctl, and may be reset via sysctl
          * to begin recalculating.
          */
         int max_dead_buffs;
 
         /**
-         * @pacer_kthread: Kernel thread that transmits packets from
-         * throttled_rpcs in a way that limits queue buildup in the
-         * NIC.
-         */
-        struct task_struct *pacer_kthread;
-
-        /**
          * @pacer_exit: true means that the pacer thread should exit as
          * soon as possible.
          */
         bool pacer_exit;
 
         /**
+         * @pacer_wait_queue: Used to block the pacer thread when there
+         * are no throttled RPCs.
+         */
+        struct wait_queue_head pacer_wait_queue;
+
+        /**
          * @max_nic_queue_ns: Limits the NIC queue length: we won't queue
          * up a packet for transmission if link_idle_time is this many
          * nanoseconds in the future (or more). Set externally via sysctl.
          */
         int max_nic_queue_ns;
 
         /**
+         * @pacer_kthread: Kernel thread that transmits packets from
+         * throttled_rpcs in a way that limits queue buildup in the
+         * NIC.
+         */
+        struct task_struct *pacer_kthread;
+
+        /**
          * @ns_per_mbyte: the number of ns that it takes to transmit
          * 10**6 bytes on our uplink. This is actually a slight overestimate
          * of the value, to ensure that we don't underestimate NIC queue
          * length and queue too many packets.
          */
         u32 ns_per_mbyte;
 
 #ifndef __STRIP__ /* See strip.py */
         /**
          * @verbose: Nonzero enables additional logging. Set externally via
@@ skipping 409 matching lines @@
 void     homa_message_out_init(struct homa_rpc *rpc, int length);
 void     homa_need_ack_pkt(struct sk_buff *skb, struct homa_sock *hsk,
                            struct homa_rpc *rpc);
 struct sk_buff *homa_new_data_packet(struct homa_rpc *rpc,
                                      struct iov_iter *iter, int offset,
                                      int length, int max_seg_data);
 int      homa_net_init(struct net *net);
 void     homa_net_exit(struct net *net);
 int      homa_pacer_main(void *transport);
 void     homa_pacer_stop(struct homa *homa);
-bool     homa_pacer_xmit(struct homa *homa);
+void     homa_pacer_xmit(struct homa *homa);
 __poll_t homa_poll(struct file *file, struct socket *sock,
                    struct poll_table_struct *wait);
 int      homa_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
                       int flags, int *addr_len);
 void     homa_remove_from_throttled(struct homa_rpc *rpc);
 void     homa_resend_pkt(struct sk_buff *skb, struct homa_rpc *rpc,
                          struct homa_sock *hsk);
 void     homa_rpc_abort(struct homa_rpc *crpc, int error);
 void     homa_rpc_acked(struct homa_sock *hsk,
                         const struct in6_addr *saddr, struct homa_ack *ack);
@@ skipping 116 matching lines @@
  * @skb:     Get the struct homa for this packet buffer.
  * Return:   see above
  */
 static inline struct homa *homa_from_skb(struct sk_buff *skb)
 {
         return (struct homa *) net_generic(dev_net(skb->dev), homa_net_id);
 }
 
 extern struct completion homa_pacer_kthread_done;
 #endif /* _HOMA_IMPL_H */