1. 05 Aug, 2014 9 commits
    • Neal Cardwell's avatar
      tcp: reduce spurious retransmits due to transient SACK reneging · 5ae344c9
      Neal Cardwell authored
      This commit reduces spurious retransmits due to apparent SACK reneging
      by only reacting to SACK reneging that persists for a short delay.
      
      When a sequence space hole at snd_una is filled, some TCP receivers
      send a series of ACKs as they apparently scan their out-of-order queue
      and cumulatively ACK all the packets that have now been consecutiveyly
      received. This is essentially misbehavior B in "Misbehaviors in TCP
      SACK generation" ACM SIGCOMM Computer Communication Review, April
      2011, so we suspect that this is from several common OSes (Windows
      2000, Windows Server 2003, Windows XP). However, this issue has also
      been seen in other cases, e.g. the netdev thread "TCP being hoodwinked
      into spurious retransmissions by lack of timestamps?" from March 2014,
      where the receiver was thought to be a BSD box.
      
      Since snd_una would temporarily be adjacent to a previously SACKed
      range in these scenarios, this receiver behavior triggered the Linux
      SACK reneging code path in the sender. This led the sender to clear
      the SACK scoreboard, enter CA_Loss, and spuriously retransmit
      (potentially) every packet from the entire write queue at line rate
      just a few milliseconds before the ACK for each packet arrives at the
      sender.
      
      To avoid such situations, now when a sender sees apparent reneging it
      does not yet retransmit, but rather adjusts the RTO timer to give the
      receiver a little time (max(RTT/2, 10ms)) to send us some more ACKs
      that will restore sanity to the SACK scoreboard. If the reneging
      persists until this RTO then, as before, we clear the SACK scoreboard
      and enter CA_Loss.
      
      A 10ms delay tolerates a receiver sending such a stream of ACKs at
      56Kbit/sec. And to allow for receivers with slower or more congested
      paths, we wait for at least RTT/2.
      
      We validated the resulting max(RTT/2, 10ms) delay formula with a mix
      of North American and South American Google web server traffic, and
      found that for ACKs displaying transient reneging:
      
       (1) 90% of inter-ACK delays were less than 10ms
       (2) 99% of inter-ACK delays were less than RTT/2
      
      In tests on Google web servers this commit reduced reneging events by
      75%-90% (as measured by the TcpExtTCPSACKReneging counter), without
      any measurable impact on latency for user HTTP and SPDY requests.
      Signed-off-by: default avatarNeal Cardwell <ncardwell@google.com>
      Signed-off-by: default avatarYuchung Cheng <ycheng@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      5ae344c9
    • David S. Miller's avatar
      Merge branch 'xen-netback-next' · 61675fea
      David S. Miller authored
      Zoltan Kiss says:
      
      ====================
      xen-netback: Changes around carrier handling
      
      This series starts using carrier off as a way to purge packets when the guest is
      not able (or willing) to receive them. It is a much faster way to get rid of
      packets waiting for an overwhelmed guest.
      The first patch changes current netback code where it relies currently on
      netif_carrier_ok.
      The second turns off the carrier if the guest times out on a queue, and only
      turn it on again if that queue (or queues) resurrects.
      ====================
      Signed-off-by: default avatarZoltan Kiss <zoltan.kiss@citrix.com>
      Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      61675fea
    • Zoltan Kiss's avatar
      xen-netback: Turn off the carrier if the guest is not able to receive · f34a4cf9
      Zoltan Kiss authored
      Currently when the guest is not able to receive more packets, qdisc layer starts
      a timer, and when it goes off, qdisc is started again to deliver a packet again.
      This is a very slow way to drain the queues, consumes unnecessary resources and
      slows down other guests shutdown.
      This patch change the behaviour by turning the carrier off when that timer
      fires, so all the packets are freed up which were stucked waiting for that vif.
      Instead of the rx_queue_purge bool it uses the VIF_STATUS_RX_PURGE_EVENT bit to
      signal the thread that either the timeout happened or an RX interrupt arrived,
      so the thread can check what it should do. It also disables NAPI, so the guest
      can't transmit, but leaves the interrupts on, so it can resurrect.
      Only the queues which brought down the interface can enable it again, the bit
      QUEUE_STATUS_RX_STALLED makes sure of that.
      Signed-off-by: default avatarZoltan Kiss <zoltan.kiss@citrix.com>
      Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
      Cc: netdev@vger.kernel.org
      Cc: linux-kernel@vger.kernel.org
      Cc: xen-devel@lists.xenproject.org
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f34a4cf9
    • Zoltan Kiss's avatar
      xen-netback: Using a new state bit instead of carrier · 3d1af1df
      Zoltan Kiss authored
      This patch introduces a new state bit VIF_STATUS_CONNECTED to track whether the
      vif is in a connected state. Using carrier will not work with the next patch
      in this series, which aims to turn the carrier temporarily off if the guest
      doesn't seem to be able to receive packets.
      Signed-off-by: default avatarZoltan Kiss <zoltan.kiss@citrix.com>
      Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
      Cc: netdev@vger.kernel.org
      Cc: linux-kernel@vger.kernel.org
      Cc: xen-devel@lists.xenproject.org
      
      v2:
      - rename the bitshift type to "enum state_bit_shift" here, not in the next patch
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      3d1af1df
    • David S. Miller's avatar
      Merge tag 'master-2014-07-31' of... · aef4f5b6
      David S. Miller authored
      Merge tag 'master-2014-07-31' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next
      
      Conflicts:
      	net/6lowpan/iphc.c
      
      Minor conflicts in iphc.c were changes overlapping with some
      style cleanups.
      
      John W. Linville says:
      
      ====================
      Please pull this last(?) batch of wireless change intended for the
      3.17 stream...
      
      For the NFC bits, Samuel says:
      
      "This is a rather quiet one, we have:
      
      - A new driver from ST Microelectronics for their NCI ST21NFCB,
        including device tree  support.
      
      - p2p support for the ST21NFCA driver
      
      - A few fixes an enhancements for the NFC digital laye"
      
      For the Atheros bits, Kalle says:
      
      "Michal and Janusz did some important RX aggregation fixes, basically we
      were missing RX reordering altogether. The 10.1 firmware doesn't support
      Ad-Hoc mode and Michal fixed ath10k so that it doesn't advertise Ad-Hoc
      support with that firmware. Also he implemented a workaround for a KVM
      issue."
      
      For the Bluetooth bits, Gustavo and Johan say:
      
      "To quote Gustavo from his previous request:
      
      'Some last minute fixes for -next. We have a fix for a use after free in
      RFCOMM, another fix to an issue with ADV_DIRECT_IND and one for ADV_IND with
      auto-connection handling.  Last, we added support for reading the codec and
      MWS setting for controllers that support these features.'
      
      Additionally there are fixes to LE scanning, an update to conform to the 4.1
      core specification as well as fixes for tracking the page scan state. All
      of these fixes are important for 3.17."
      
      And,
      
      "We've got:
      
      - 6lowpan fixes/cleanups
      - A couple crash fixes, one for the Marvell HCI driver and another in LE SMP.
      - Fix for an incorrect connected state check
      - Fix for the bondable requirement during pairing (an issue which had
        crept in because of using "pairable" when in fact the actual meaning
        was "bondable" (these have different meanings in Bluetooth)"
      
      Along with those are some late-breaking hardware support patches in
      brcmfmac and b43 as well as a stray ath9k patch.
      ====================
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      aef4f5b6
    • Ricardo Ribalda's avatar
      net/usb/hso: Add support for Option GTM671WFS · 61ab9efd
      Ricardo Ribalda authored
      After this patch:
      
      [   32.985530] hso: drivers/net/usb/hso.c: Option Wireless
      [   33.000452] hso 2-1.4:1.7: Not our interface
      [   33.001849] usbcore: registered new interface driver hso
      
      root@qt5022:~# ls /dev/ttyHS*
      /dev/ttyHS0  /dev/ttyHS1  /dev/ttyHS2  /dev/ttyHS3  /dev/ttyHS4
      /dev/ttyHS5
      
      root@qt5022:~# lsusb -d 0af0: -vvv
      
      Bus 002 Device 003: ID 0af0:9200 Option
      Device Descriptor:
        bLength                18
        bDescriptorType         1
        bcdUSB               2.00
        bDeviceClass          255 Vendor Specific Class
        bDeviceSubClass       255 Vendor Specific Subclass
        bDeviceProtocol       255 Vendor Specific Protocol
        bMaxPacketSize0        64
        idVendor           0x0af0 Option
        idProduct          0x9200
        bcdDevice            0.00
        iManufacturer           3 Option N.V.
        iProduct                2 Globetrotter HSUPA Modem
        iSerial                 0
        bNumConfigurations      1
        Configuration Descriptor:
          bLength                 9
          bDescriptorType         2
          wTotalLength          200
          bNumInterfaces          8
          bConfigurationValue     1
          iConfiguration          1 Option Configuration
          bmAttributes         0xe0
            Self Powered
            Remote Wakeup
          MaxPower              100mA
          Interface Descriptor:
            bLength                 9
            bDescriptorType         4
            bInterfaceNumber        0
            bAlternateSetting       0
            bNumEndpoints           2
            bInterfaceClass       255 Vendor Specific Class
            bInterfaceSubClass    255 Vendor Specific Subclass
            bInterfaceProtocol    255 Vendor Specific Protocol
            iInterface              0
            Endpoint Descriptor:
              bLength                 7
              bDescriptorType         5
              bEndpointAddress     0x81  EP 1 IN
              bmAttributes            2
                Transfer Type            Bulk
                Synch Type               None
                Usage Type               Data
              wMaxPacketSize     0x0200  1x 512 bytes
              bInterval              32
            Endpoint Descriptor:
              bLength                 7
              bDescriptorType         5
              bEndpointAddress     0x01  EP 1 OUT
              bmAttributes            2
                Transfer Type            Bulk
                Synch Type               None
                Usage Type               Data
              wMaxPacketSize     0x0200  1x 512 bytes
              bInterval              32
          Interface Descriptor:
            bLength                 9
            bDescriptorType         4
            bInterfaceNumber        1
            bAlternateSetting       0
            bNumEndpoints           2
            bInterfaceClass       255 Vendor Specific Class
            bInterfaceSubClass    255 Vendor Specific Subclass
            bInterfaceProtocol    255 Vendor Specific Protocol
            iInterface              0
            Endpoint Descriptor:
              bLength                 7
              bDescriptorType         5
              bEndpointAddress     0x82  EP 2 IN
              bmAttributes            2
                Transfer Type            Bulk
                Synch Type               None
                Usage Type               Data
              wMaxPacketSize     0x0200  1x 512 bytes
              bInterval              32
            Endpoint Descriptor:
              bLength                 7
              bDescriptorType         5
              bEndpointAddress     0x02  EP 2 OUT
              bmAttributes            2
                Transfer Type            Bulk
                Synch Type               None
                Usage Type               Data
              wMaxPacketSize     0x0200  1x 512 bytes
              bInterval              32
          Interface Descriptor:
            bLength                 9
            bDescriptorType         4
            bInterfaceNumber        2
            bAlternateSetting       0
            bNumEndpoints           2
            bInterfaceClass       255 Vendor Specific Class
            bInterfaceSubClass    255 Vendor Specific Subclass
            bInterfaceProtocol    255 Vendor Specific Protocol
            iInterface              0
            Endpoint Descriptor:
              bLength                 7
              bDescriptorType         5
              bEndpointAddress     0x83  EP 3 IN
              bmAttributes            2
                Transfer Type            Bulk
                Synch Type               None
                Usage Type               Data
              wMaxPacketSize     0x0200  1x 512 bytes
              bInterval              32
            Endpoint Descriptor:
              bLength                 7
              bDescriptorType         5
              bEndpointAddress     0x03  EP 3 OUT
              bmAttributes            2
                Transfer Type            Bulk
                Synch Type               None
                Usage Type               Data
              wMaxPacketSize     0x0200  1x 512 bytes
              bInterval              32
          Interface Descriptor:
            bLength                 9
            bDescriptorType         4
            bInterfaceNumber        3
            bAlternateSetting       0
            bNumEndpoints           2
            bInterfaceClass       255 Vendor Specific Class
            bInterfaceSubClass    255 Vendor Specific Subclass
            bInterfaceProtocol    255 Vendor Specific Protocol
            iInterface              0
            Endpoint Descriptor:
              bLength                 7
              bDescriptorType         5
              bEndpointAddress     0x84  EP 4 IN
              bmAttributes            2
                Transfer Type            Bulk
                Synch Type               None
                Usage Type               Data
              wMaxPacketSize     0x0200  1x 512 bytes
              bInterval              32
            Endpoint Descriptor:
              bLength                 7
              bDescriptorType         5
              bEndpointAddress     0x04  EP 4 OUT
              bmAttributes            2
                Transfer Type            Bulk
                Synch Type               None
                Usage Type               Data
              wMaxPacketSize     0x0200  1x 512 bytes
              bInterval              32
          Interface Descriptor:
            bLength                 9
            bDescriptorType         4
            bInterfaceNumber        4
            bAlternateSetting       0
            bNumEndpoints           2
            bInterfaceClass       255 Vendor Specific Class
            bInterfaceSubClass    255 Vendor Specific Subclass
            bInterfaceProtocol    255 Vendor Specific Protocol
            iInterface              0
            Endpoint Descriptor:
              bLength                 7
              bDescriptorType         5
              bEndpointAddress     0x85  EP 5 IN
              bmAttributes            2
                Transfer Type            Bulk
                Synch Type               None
                Usage Type               Data
              wMaxPacketSize     0x0200  1x 512 bytes
              bInterval              32
            Endpoint Descriptor:
              bLength                 7
              bDescriptorType         5
              bEndpointAddress     0x05  EP 5 OUT
              bmAttributes            2
                Transfer Type            Bulk
                Synch Type               None
                Usage Type               Data
              wMaxPacketSize     0x0200  1x 512 bytes
              bInterval              32
          Interface Descriptor:
            bLength                 9
            bDescriptorType         4
            bInterfaceNumber        5
            bAlternateSetting       0
            bNumEndpoints           2
            bInterfaceClass       255 Vendor Specific Class
            bInterfaceSubClass    255 Vendor Specific Subclass
            bInterfaceProtocol    255 Vendor Specific Protocol
            iInterface              0
            Endpoint Descriptor:
              bLength                 7
              bDescriptorType         5
              bEndpointAddress     0x06  EP 6 OUT
              bmAttributes            2
                Transfer Type            Bulk
                Synch Type               None
                Usage Type               Data
              wMaxPacketSize     0x0200  1x 512 bytes
              bInterval              32
            Endpoint Descriptor:
              bLength                 7
              bDescriptorType         5
              bEndpointAddress     0x86  EP 6 IN
              bmAttributes            2
                Transfer Type            Bulk
                Synch Type               None
                Usage Type               Data
              wMaxPacketSize     0x0200  1x 512 bytes
              bInterval              32
          Interface Descriptor:
            bLength                 9
            bDescriptorType         4
            bInterfaceNumber        6
            bAlternateSetting       0
            bNumEndpoints           3
            bInterfaceClass       255 Vendor Specific Class
            bInterfaceSubClass    255 Vendor Specific Subclass
            bInterfaceProtocol    255 Vendor Specific Protocol
            iInterface              0
            Endpoint Descriptor:
              bLength                 7
              bDescriptorType         5
              bEndpointAddress     0x87  EP 7 IN
              bmAttributes            3
                Transfer Type            Interrupt
                Synch Type               None
                Usage Type               Data
              wMaxPacketSize     0x0040  1x 64 bytes
              bInterval               5
            Endpoint Descriptor:
              bLength                 7
              bDescriptorType         5
              bEndpointAddress     0x88  EP 8 IN
              bmAttributes            2
                Transfer Type            Bulk
                Synch Type               None
                Usage Type               Data
              wMaxPacketSize     0x0200  1x 512 bytes
              bInterval              32
            Endpoint Descriptor:
              bLength                 7
              bDescriptorType         5
              bEndpointAddress     0x07  EP 7 OUT
              bmAttributes            2
                Transfer Type            Bulk
                Synch Type               None
                Usage Type               Data
              wMaxPacketSize     0x0200  1x 512 bytes
              bInterval              32
          Interface Descriptor:
            bLength                 9
            bDescriptorType         4
            bInterfaceNumber        7
            bAlternateSetting       0
            bNumEndpoints           2
            bInterfaceClass         8 Mass Storage
            bInterfaceSubClass      6 SCSI
            bInterfaceProtocol     80 Bulk-Only
            iInterface              0
            Endpoint Descriptor:
              bLength                 7
              bDescriptorType         5
              bEndpointAddress     0x08  EP 8 OUT
              bmAttributes            2
                Transfer Type            Bulk
                Synch Type               None
                Usage Type               Data
              wMaxPacketSize     0x0200  1x 512 bytes
              bInterval               1
            Endpoint Descriptor:
              bLength                 7
              bDescriptorType         5
              bEndpointAddress     0x89  EP 9 IN
              bmAttributes            2
                Transfer Type            Bulk
                Synch Type               None
                Usage Type               Data
              wMaxPacketSize     0x0200  1x 512 bytes
              bInterval               1
      Device Qualifier (for other device speed):
        bLength                10
        bDescriptorType         6
        bcdUSB               2.00
        bDeviceClass          255 Vendor Specific Class
        bDeviceSubClass       255 Vendor Specific Subclass
        bDeviceProtocol       255 Vendor Specific Protocol
        bMaxPacketSize0        64
        bNumConfigurations      1
      Device Status:     0x0001
        Self Powered
      Signed-off-by: default avatarRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
      Acked-by: default avatarDan Williams <dcbw@redhat.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      61ab9efd
    • Hans Wennborg's avatar
    • Hans Wennborg's avatar
    • Eric Dumazet's avatar
      netlink: fix lockdep splats · 67a24ac1
      Eric Dumazet authored
      With netlink_lookup() conversion to RCU, we need to use appropriate
      rcu dereference in netlink_seq_socket_idx() & netlink_seq_next()
      Reported-by: default avatarSasha Levin <sasha.levin@oracle.com>
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Fixes: e341694e ("netlink: Convert netlink_lookup() to use RCU protected hash table")
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      67a24ac1
  2. 04 Aug, 2014 6 commits
  3. 03 Aug, 2014 23 commits
  4. 02 Aug, 2014 2 commits