1. 28 Sep, 2011 2 commits
    • Changli Gao's avatar
      net: rps: fix the support for PPPOE · 5dd17e08
      Changli Gao authored
      The upper protocol numbers of PPPOE are different, and should be treated
      specially.
      Signed-off-by: default avatarChangli Gao <xiaosuo@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      5dd17e08
    • Eric Dumazet's avatar
      af_unix: dont send SCM_CREDENTIALS by default · 16e57262
      Eric Dumazet authored
      Since commit 7361c36c (af_unix: Allow credentials to work across
      user and pid namespaces) af_unix performance dropped a lot.
      
      This is because we now take a reference on pid and cred in each write(),
      and release them in read(), usually done from another process,
      eventually from another cpu. This triggers false sharing.
      
      # Events: 154K cycles
      #
      # Overhead  Command       Shared Object        Symbol
      # ........  .......  ..................  .........................
      #
          10.40%  hackbench  [kernel.kallsyms]   [k] put_pid
           8.60%  hackbench  [kernel.kallsyms]   [k] unix_stream_recvmsg
           7.87%  hackbench  [kernel.kallsyms]   [k] unix_stream_sendmsg
           6.11%  hackbench  [kernel.kallsyms]   [k] do_raw_spin_lock
           4.95%  hackbench  [kernel.kallsyms]   [k] unix_scm_to_skb
           4.87%  hackbench  [kernel.kallsyms]   [k] pid_nr_ns
           4.34%  hackbench  [kernel.kallsyms]   [k] cred_to_ucred
           2.39%  hackbench  [kernel.kallsyms]   [k] unix_destruct_scm
           2.24%  hackbench  [kernel.kallsyms]   [k] sub_preempt_count
           1.75%  hackbench  [kernel.kallsyms]   [k] fget_light
           1.51%  hackbench  [kernel.kallsyms]   [k]
      __mutex_lock_interruptible_slowpath
           1.42%  hackbench  [kernel.kallsyms]   [k] sock_alloc_send_pskb
      
      This patch includes SCM_CREDENTIALS information in a af_unix message/skb
      only if requested by the sender, [man 7 unix for details how to include
      ancillary data using sendmsg() system call]
      
      Note: This might break buggy applications that expected SCM_CREDENTIAL
      from an unaware write() system call, and receiver not using SO_PASSCRED
      socket option.
      
      If SOCK_PASSCRED is set on source or destination socket, we still
      include credentials for mere write() syscalls.
      
      Performance boost in hackbench : more than 50% gain on a 16 thread
      machine (2 quad-core cpus, 2 threads per core)
      
      hackbench 20 thread 2000
      
      4.228 sec instead of 9.102 sec
      Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
      Acked-by: default avatarTim Chen <tim.c.chen@linux.intel.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      16e57262
  2. 27 Sep, 2011 13 commits
  3. 26 Sep, 2011 3 commits
  4. 23 Sep, 2011 18 commits
  5. 22 Sep, 2011 4 commits