1. 11 4月, 2012 1 次提交
    • E
      tcp: restore correct limit · 5fb84b14
      Eric Dumazet 提交于
      Commit c43b874d (tcp: properly initialize tcp memory limits) tried
      to fix a regression added in commits 4acb4190 & 3dc43e3e,
      but still get it wrong.
      
      Result is machines with low amount of memory have too small tcp_rmem[2]
      value and slow tcp receives : Per socket limit being 1/1024 of memory
      instead of 1/128 in old kernels, so rcv window is capped to small
      values.
      
      Fix this to match comment and previous behavior.
      Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
      Cc: Jason Wang <jasowang@redhat.com>
      Cc: Glauber Costa <glommer@parallels.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      5fb84b14
  2. 06 4月, 2012 1 次提交
    • E
      tcp: tcp_sendpages() should call tcp_push() once · 35f9c09f
      Eric Dumazet 提交于
      commit 2f533844 (tcp: allow splice() to build full TSO packets) added
      a regression for splice() calls using SPLICE_F_MORE.
      
      We need to call tcp_flush() at the end of the last page processed in
      tcp_sendpages(), or else transmits can be deferred and future sends
      stall.
      
      Add a new internal flag, MSG_SENDPAGE_NOTLAST, acting like MSG_MORE, but
      with different semantic.
      
      For all sendpage() providers, its a transparent change. Only
      sock_sendpage() and tcp_sendpages() can differentiate the two different
      flags provided by pipe_to_sendpage()
      Reported-by: NTom Herbert <therbert@google.com>
      Cc: Nandita Dukkipati <nanditad@google.com>
      Cc: Neal Cardwell <ncardwell@google.com>
      Cc: Tom Herbert <therbert@google.com>
      Cc: Yuchung Cheng <ycheng@google.com>
      Cc: H.K. Jerry Chu <hkchu@google.com>
      Cc: Maciej Żenczykowski <maze@google.com>
      Cc: Mahesh Bandewar <maheshb@google.com>
      Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
      Signed-off-by: NEric Dumazet <eric.dumazet@gmail&gt;com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      35f9c09f
  3. 04 4月, 2012 1 次提交
    • E
      tcp: allow splice() to build full TSO packets · 2f533844
      Eric Dumazet 提交于
      vmsplice()/splice(pipe, socket) call do_tcp_sendpages() one page at a
      time, adding at most 4096 bytes to an skb. (assuming PAGE_SIZE=4096)
      
      The call to tcp_push() at the end of do_tcp_sendpages() forces an
      immediate xmit when pipe is not already filled, and tso_fragment() try
      to split these skb to MSS multiples.
      
      4096 bytes are usually split in a skb with 2 MSS, and a remaining
      sub-mss skb (assuming MTU=1500)
      
      This makes slow start suboptimal because many small frames are sent to
      qdisc/driver layers instead of big ones (constrained by cwnd and packets
      in flight of course)
      
      In fact, applications using sendmsg() (adding an additional memory copy)
      instead of vmsplice()/splice()/sendfile() are a bit faster because of
      this anomaly, especially if serving small files in environments with
      large initial [c]wnd.
      
      Call tcp_push() only if MSG_MORE is not set in the flags parameter.
      
      This bit is automatically provided by splice() internals but for the
      last page, or on all pages if user specified SPLICE_F_MORE splice()
      flag.
      
      In some workloads, this can reduce number of sent logical packets by an
      order of magnitude, making zero-copy TCP actually faster than
      one-copy :)
      Reported-by: NTom Herbert <therbert@google.com>
      Cc: Nandita Dukkipati <nanditad@google.com>
      Cc: Neal Cardwell <ncardwell@google.com>
      Cc: Tom Herbert <therbert@google.com>
      Cc: Yuchung Cheng <ycheng@google.com>
      Cc: H.K. Jerry Chu <hkchu@google.com>
      Cc: Maciej Żenczykowski <maze@google.com>
      Cc: Mahesh Bandewar <maheshb@google.com>
      Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
      Signed-off-by: NEric Dumazet <eric.dumazet@gmail&gt;com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2f533844
  4. 13 3月, 2012 1 次提交
  5. 12 3月, 2012 1 次提交
    • J
      net: Convert printks to pr_<level> · 058bd4d2
      Joe Perches 提交于
      Use a more current kernel messaging style.
      
      Convert a printk block to print_hex_dump.
      Coalesce formats, align arguments.
      Use %s, __func__ instead of embedding function names.
      
      Some messages that were prefixed with <foo>_close are
      now prefixed with <foo>_fini.  Some ah4 and esp messages
      are now not prefixed with "ip ".
      
      The intent of this patch is to later add something like
        #define pr_fmt(fmt) "IPv4: " fmt.
      to standardize the output messages.
      
      Text size is trivially reduced. (x86-32 allyesconfig)
      
      $ size net/ipv4/built-in.o*
         text	   data	    bss	    dec	    hex	filename
       887888	  31558	 249696	1169142	 11d6f6	net/ipv4/built-in.o.new
       887934	  31558	 249800	1169292	 11d78c	net/ipv4/built-in.o.old
      Signed-off-by: NJoe Perches <joe@perches.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      058bd4d2
  6. 14 2月, 2012 1 次提交
  7. 03 2月, 2012 1 次提交
  8. 02 2月, 2012 1 次提交
    • A
      net: Disambiguate kernel message · efcdbf24
      Arun Sharma 提交于
      Some of our machines were reporting:
      
      TCP: too many of orphaned sockets
      
      even when the number of orphaned sockets was well below the
      limit.
      
      We print a different message depending on whether we're out
      of TCP memory or there are too many orphaned sockets.
      
      Also move the check out of line and cleanup the messages
      that were printed.
      Signed-off-by: NArun Sharma <asharma@fb.com>
      Suggested-by: NMohan Srinivasan <mohan@fb.com>
      Cc: netdev@vger.kernel.org
      Cc: linux-kernel@vger.kernel.org
      Cc: David Miller <davem@davemloft.net>
      Cc: Glauber Costa <glommer@parallels.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Joe Perches <joe@perches.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      efcdbf24
  9. 31 1月, 2012 1 次提交
  10. 13 12月, 2011 1 次提交
  11. 06 12月, 2011 1 次提交
  12. 05 12月, 2011 1 次提交
  13. 30 11月, 2011 1 次提交
    • E
      tcp: avoid frag allocation for small frames · f07d960d
      Eric Dumazet 提交于
      tcp_sendmsg() uses select_size() helper to choose skb head size when a
      new skb must be allocated.
      
      If GSO is enabled for the socket, current strategy is to force all
      payload data to be outside of headroom, in PAGE fragments.
      
      This strategy is not welcome for small packets, wasting memory.
      
      Experiments show that best results are obtained when using 2048 bytes
      for skb head (This includes the skb overhead and various headers)
      
      This patch provides better len/truesize ratios for packets sent to
      loopback device, and reduce memory needs for in-flight loopback packets,
      particularly on arches with big pages.
      
      If a sender sends many 1-byte packets to an unresponsive application,
      receiver rmem_alloc will grow faster and will stop queuing these packets
      sooner, or will collapse its receive queue to free excess memory.
      
      netperf -t TCP_RR results are improved by ~4 %, and many workloads are
      improved as well (tbench, mysql...)
      Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f07d960d
  14. 29 11月, 2011 1 次提交
  15. 17 11月, 2011 1 次提交
  16. 25 10月, 2011 1 次提交
  17. 24 10月, 2011 1 次提交
  18. 21 10月, 2011 1 次提交
  19. 19 10月, 2011 1 次提交
  20. 04 10月, 2011 1 次提交
    • E
      tcp: report ECN_SEEN in tcp_info · b5c5693b
      Eric Dumazet 提交于
      Allows ss command (iproute2) to display "ecnseen" if at least one packet
      with ECT(0) or ECT(1) or ECN was received by this socket.
      
      "ecn" means ECN was negotiated at session establishment (TCP level)
      
      "ecnseen" means we received at least one packet with ECT fields set (IP
      level)
      
      ss -i
      ...
      ESTAB      0      0   192.168.20.110:22  192.168.20.144:38016
      ino:5950 sk:f178e400
      	 mem:(r0,w0,f0,t0) ts sack ecn ecnseen bic wscale:7,8 rto:210
      rtt:12.5/7.5 cwnd:10 send 9.3Mbps rcv_space:14480
      Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      b5c5693b
  21. 28 9月, 2011 1 次提交
  22. 17 9月, 2011 1 次提交
  23. 25 8月, 2011 1 次提交
  24. 07 7月, 2011 1 次提交
  25. 05 4月, 2011 1 次提交
    • T
      net: Allow no-cache copy from user on transmit · c6e1a0d1
      Tom Herbert 提交于
      This patch uses __copy_from_user_nocache on transmit to bypass data
      cache for a performance improvement.  skb_add_data_nocache and
      skb_copy_to_page_nocache can be called by sendmsg functions to use
      this feature, initial support is in tcp_sendmsg.  This functionality is
      configurable per device using ethtool.
      
      Presumably, this feature would only be useful when the driver does
      not touch the data.  The feature is turned on by default if a device
      indicates that it does some form of checksum offload; it is off by
      default for devices that do no checksum offload or indicate no checksum
      is necessary.  For the former case copy-checksum is probably done
      anyway, in the latter case the device is likely loopback in which case
      the no cache copy is probably not beneficial.
      
      This patch was tested using 200 instances of netperf TCP_RR with
      1400 byte request and one byte reply.  Platform is 16 core AMD x86.
      
      No-cache copy disabled:
         672703 tps, 97.13% utilization
         50/90/99% latency:244.31 484.205 1028.41
      
      No-cache copy enabled:
         702113 tps, 96.16% utilization,
         50/90/99% latency 238.56 467.56 956.955
      
      Using 14000 byte request and response sizes demonstrate the
      effects more dramatically:
      
      No-cache copy disabled:
         79571 tps, 34.34 %utlization
         50/90/95% latency 1584.46 2319.59 5001.76
      
      No-cache copy enabled:
         83856 tps, 34.81% utilization
         50/90/95% latency 2508.42 2622.62 2735.88
      
      Note especially the effect on latency tail (95th percentile).
      
      This seems to provide a nice performance improvement and is
      consistent in the tests I ran.  Presumably, this would provide
      the greatest benfits in the presence of an application workload
      stressing the cache and a lot of transmit data happening.
      Signed-off-by: NTom Herbert <therbert@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      c6e1a0d1
  26. 10 3月, 2011 1 次提交
  27. 21 2月, 2011 1 次提交
  28. 25 1月, 2011 1 次提交
  29. 25 11月, 2010 1 次提交
  30. 11 11月, 2010 2 次提交
  31. 10 11月, 2010 1 次提交
  32. 28 9月, 2010 1 次提交
  33. 21 9月, 2010 1 次提交
  34. 31 8月, 2010 1 次提交
    • J
      tcp: Add TCP_USER_TIMEOUT socket option. · dca43c75
      Jerry Chu 提交于
      This patch provides a "user timeout" support as described in RFC793. The
      socket option is also needed for the the local half of RFC5482 "TCP User
      Timeout Option".
      
      TCP_USER_TIMEOUT is a TCP level socket option that takes an unsigned int,
      when > 0, to specify the maximum amount of time in ms that transmitted
      data may remain unacknowledged before TCP will forcefully close the
      corresponding connection and return ETIMEDOUT to the application. If
      0 is given, TCP will continue to use the system default.
      
      Increasing the user timeouts allows a TCP connection to survive extended
      periods without end-to-end connectivity. Decreasing the user timeouts
      allows applications to "fail fast" if so desired. Otherwise it may take
      upto 20 minutes with the current system defaults in a normal WAN
      environment.
      
      The socket option can be made during any state of a TCP connection, but
      is only effective during the synchronized states of a connection
      (ESTABLISHED, FIN-WAIT-1, FIN-WAIT-2, CLOSE-WAIT, CLOSING, or LAST-ACK).
      Moreover, when used with the TCP keepalive (SO_KEEPALIVE) option,
      TCP_USER_TIMEOUT will overtake keepalive to determine when to close a
      connection due to keepalive failure.
      
      The option does not change in anyway when TCP retransmits a packet, nor
      when a keepalive probe will be sent.
      
      This option, like many others, will be inherited by an acceptor from its
      listener.
      Signed-off-by: NH.K. Jerry Chu <hkchu@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      dca43c75
  35. 26 8月, 2010 2 次提交
    • K
      tcp: select(writefds) don't hang up when a peer close connection · d84ba638
      KOSAKI Motohiro 提交于
      This issue come from ruby language community. Below test program
      hang up when only run on Linux.
      
      	% uname -mrsv
      	Linux 2.6.26-2-486 #1 Sat Dec 26 08:37:39 UTC 2009 i686
      	% ruby -rsocket -ve '
      	BasicSocket.do_not_reverse_lookup = true
      	serv = TCPServer.open("127.0.0.1", 0)
      	s1 = TCPSocket.open("127.0.0.1", serv.addr[1])
      	s2 = serv.accept
      	s2.close
      	s1.write("a") rescue p $!
      	s1.write("a") rescue p $!
      	Thread.new {
      	  s1.write("a")
      	}.join'
      	ruby 1.9.3dev (2010-07-06 trunk 28554) [i686-linux]
      	#<Errno::EPIPE: Broken pipe>
      	[Hang Here]
      
      FreeBSD, Solaris, Mac doesn't. because Ruby's write() method call
      select() internally. and tcp_poll has a bug.
      
      SUS defined 'ready for writing' of select() as following.
      
      |  A descriptor shall be considered ready for writing when a call to an output
      |  function with O_NONBLOCK clear would not block, whether or not the function
      |  would transfer data successfully.
      
      That said, EPIPE situation is clearly one of 'ready for writing'.
      
      We don't have read-side issue because tcp_poll() already has read side
      shutdown care.
      
      |        if (sk->sk_shutdown & RCV_SHUTDOWN)
      |                mask |= POLLIN | POLLRDNORM | POLLRDHUP;
      
      So, Let's insert same logic in write side.
      
      - reference url
        http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-core/31065
        http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-core/31068Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d84ba638
    • E
      tcp: fix three tcp sysctls tuning · c5ed63d6
      Eric Dumazet 提交于
      As discovered by Anton Blanchard, current code to autotune 
      tcp_death_row.sysctl_max_tw_buckets, sysctl_tcp_max_orphans and
      sysctl_max_syn_backlog makes little sense.
      
      The bigger a page is, the less tcp_max_orphans is : 4096 on a 512GB
      machine in Anton's case.
      
      (tcp_hashinfo.bhash_size * sizeof(struct inet_bind_hashbucket))
      is much bigger if spinlock debugging is on. Its wrong to select bigger
      limits in this case (where kernel structures are also bigger)
      
      bhash_size max is 65536, and we get this value even for small machines. 
      
      A better ground is to use size of ehash table, this also makes code
      shorter and more obvious.
      
      Based on a patch from Anton, and another from David.
      Reported-and-tested-by: NAnton Blanchard <anton@samba.org>
      Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      c5ed63d6
  36. 25 8月, 2010 1 次提交
  37. 03 8月, 2010 1 次提交
  38. 31 7月, 2010 1 次提交