1. 02 5月, 2010 1 次提交
    • E
      net: sock_def_readable() and friends RCU conversion · 43815482
      Eric Dumazet 提交于
      sk_callback_lock rwlock actually protects sk->sk_sleep pointer, so we
      need two atomic operations (and associated dirtying) per incoming
      packet.
      
      RCU conversion is pretty much needed :
      
      1) Add a new structure, called "struct socket_wq" to hold all fields
      that will need rcu_read_lock() protection (currently: a
      wait_queue_head_t and a struct fasync_struct pointer).
      
      [Future patch will add a list anchor for wakeup coalescing]
      
      2) Attach one of such structure to each "struct socket" created in
      sock_alloc_inode().
      
      3) Respect RCU grace period when freeing a "struct socket_wq"
      
      4) Change sk_sleep pointer in "struct sock" by sk_wq, pointer to "struct
      socket_wq"
      
      5) Change sk_sleep() function to use new sk->sk_wq instead of
      sk->sk_sleep
      
      6) Change sk_has_sleeper() to wq_has_sleeper() that must be used inside
      a rcu_read_lock() section.
      
      7) Change all sk_has_sleeper() callers to :
        - Use rcu_read_lock() instead of read_lock(&sk->sk_callback_lock)
        - Use wq_has_sleeper() to eventually wakeup tasks.
        - Use rcu_read_unlock() instead of read_unlock(&sk->sk_callback_lock)
      
      8) sock_wake_async() is modified to use rcu protection as well.
      
      9) Exceptions :
        macvtap, drivers/net/tun.c, af_unix use integrated "struct socket_wq"
      instead of dynamically allocated ones. They dont need rcu freeing.
      
      Some cleanups or followups are probably needed, (possible
      sk_callback_lock conversion to a spinlock for example...).
      Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      43815482
  2. 01 5月, 2010 5 次提交
  3. 29 4月, 2010 30 次提交
  4. 28 4月, 2010 4 次提交