916 False-sharing in TCP hash buckets, plus size increase
        (originally Joyent OS-299 tcp_bindi() hash lock contention affects
        TCP client performance)

*** 18,27 ****
--- 18,28 ----
   *
   * CDDL HEADER END
   */
  /*
   * Copyright (c) 1991, 2010, Oracle and/or its affiliates. All rights reserved.
+  * Copyright (c) 2011, Joyent, Inc. All rights reserved.
   */
  /* Copyright (c) 1990 Mentat Inc. */
  
  #ifndef _INET_TCP_H
  #define _INET_TCP_H
*** 494,503 ****
--- 495,507 ----
  extern void     tcp_ddi_g_destroy(void);
  extern void     *tcp_get_conn(void *arg, tcp_stack_t *);
  extern mblk_t   *tcp_snmp_get(queue_t *, mblk_t *, boolean_t);
  extern int      tcp_snmp_set(queue_t *, int, int, uchar_t *, int len);
  
+ /* Pad for the tf_t structure to avoid false cache line sharing. */
+ #define TF_CACHEL_PAD   64
+ 
  /*
   * The TCP Fanout structure for bind and acceptor hashes.
   * The hash tables and their linkage (tcp_*_hash, tcp_ptp*hn) are
   * protected by the per-bucket tf_lock.  Each tcp_t
   * inserted in the list points back at this lock using tcp_*_lockp.
*** 506,515 ****
--- 510,521 ----
   */
  /* listener hash and acceptor hash queue head */
  typedef struct tf_s {
          tcp_t           *tf_tcp;
          kmutex_t        tf_lock;
+         unsigned char   tf_pad[TF_CACHEL_PAD -
+             (sizeof (tcp_t *) + sizeof (kmutex_t))];
  } tf_t;
  
  
  /* Also used in ipclassifier.c */
  extern struct kmem_cache  *tcp_sack_info_cache;