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  1. 11 Feb, 2022 8 commits
    • D. Wythe's avatar
      net/smc: Add global configure for handshake limitation by netlink · f9496b7c
      D. Wythe authored 
      Although we can control SMC handshake limitation through socket options,
which means that applications who need it must modify their code. It's
quite troublesome for many existing applications. This patch modifies
the global default value of SMC handshake limitation through netlink,
providing a way to put constraint on handshake without modifies any code
for applications.
Suggested-by: default avatarTony Lu <tonylu@linux.alibaba.com>
Signed-off-by: default avatarD. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: default avatarTony Lu <tonylu@linux.alibaba.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f9496b7c
    • D. Wythe's avatar
      net/smc: Dynamic control handshake limitation by socket options · a6a6fe27
      D. Wythe authored 
      This patch aims to add dynamic control for SMC handshake limitation for
every smc sockets, in production environment, it is possible for the
same applications to handle different service types, and may have
different opinion on SMC handshake limitation.

This patch try socket options to complete it, since we don't have socket
option level for SMC yet, which requires us to implement it at the same
time.

This patch does the following:

- add new socket option level: SOL_SMC.
- add new SMC socket option: SMC_LIMIT_HS.
- provide getter/setter for SMC socket options.

Link: https://lore.kernel.org/all/20f504f961e1a803f85d64229ad84260434203bd.1644323503.git.alibuda@linux.alibaba.com/Signed-off-by: default avatarD. Wythe <alibuda@linux.alibaba.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a6a6fe27
    • D. Wythe's avatar
      net/smc: Limit SMC visits when handshake workqueue congested · 48b6190a
      D. Wythe authored 
      This patch intends to provide a mechanism to put constraint on SMC
connections visit according to the pressure of SMC handshake process.
At present, frequent visits will cause the incoming connections to be
backlogged in SMC handshake queue, raise the connections established
time. Which is quite unacceptable for those applications who base on
short lived connections.

There are two ways to implement this mechanism:

1. Put limitation after TCP established.
2. Put limitation before TCP established.

In the first way, we need to wait and receive CLC messages that the
client will potentially send, and then actively reply with a decline
message, in a sense, which is also a sort of SMC handshake, affect the
connections established time on its way.

In the second way, the only problem is that we need to inject SMC logic
into TCP when it is about to reply the incoming SYN, since we already do
that, it's seems not a problem anymore. And advantage is obvious, few
additional processes are required to complete the constraint.

This patch use the second way. After this patch, connections who beyond
constraint will not informed any SMC indication, and SMC will not be
involved in any of its subsequent processes.

Link: https://lore.kernel.org/all/1641301961-59331-1-git-send-email-alibuda@linux.alibaba.com/Signed-off-by: default avatarD. Wythe <alibuda@linux.alibaba.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      48b6190a
    • D. Wythe's avatar
      net/smc: Limit backlog connections · 8270d9c2
      D. Wythe authored 
      Current implementation does not handling backlog semantics, one
potential risk is that server will be flooded by infinite amount
connections, even if client was SMC-incapable.

This patch works to put a limit on backlog connections, referring to the
TCP implementation, we divides SMC connections into two categories:

1. Half SMC connection, which includes all TCP established while SMC not
connections.

2. Full SMC connection, which includes all SMC established connections.

For half SMC connection, since all half SMC connections starts with TCP
established, we can achieve our goal by put a limit before TCP
established. Refer to the implementation of TCP, this limits will based
on not only the half SMC connections but also the full connections,
which is also a constraint on full SMC connections.

For full SMC connections, although we know exactly where it starts, it's
quite hard to put a limit before it. The easiest way is to block wait
before receive SMC confirm CLC message, while it's under protection by
smc_server_lgr_pending, a global lock, which leads this limit to the
entire host instead of a single listen socket. Another way is to drop
the full connections, but considering the cast of SMC connections, we
prefer to keep full SMC connections.

Even so, the limits of full SMC connections still exists, see commits
about half SMC connection below.

After this patch, the limits of backend connection shows like:

For SMC:

1. Client with SMC-capability can makes 2 * backlog full SMC connections
   or 1 * backlog half SMC connections and 1 * backlog full SMC
   connections at most.

2. Client without SMC-capability can only makes 1 * backlog half TCP
   connections and 1 * backlog full TCP connections.
Signed-off-by: default avatarD. Wythe <alibuda@linux.alibaba.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      8270d9c2
    • D. Wythe's avatar
      net/smc: Make smc_tcp_listen_work() independent · 3079e342
      D. Wythe authored 
      In multithread and 10K connections benchmark, the backend TCP connection
established very slowly, and lots of TCP connections stay in SYN_SENT
state.

Client: smc_run wrk -c 10000 -t 4 http://server

the netstate of server host shows like:
    145042 times the listen queue of a socket overflowed
    145042 SYNs to LISTEN sockets dropped

One reason of this issue is that, since the smc_tcp_listen_work() shared
the same workqueue (smc_hs_wq) with smc_listen_work(), while the
smc_listen_work() do blocking wait for smc connection established. Once
the workqueue became congested, it's will block the accept() from TCP
listen.

This patch creates a independent workqueue(smc_tcp_ls_wq) for
smc_tcp_listen_work(), separate it from smc_listen_work(), which is
quite acceptable considering that smc_tcp_listen_work() runs very fast.
Signed-off-by: default avatarD. Wythe <alibuda@linux.alibaba.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      3079e342
    • Luiz Angelo Daros de Luca's avatar
      dt-bindings: net: dsa: realtek: convert to YAML schema, add MDIO · 429c83c7
      Luiz Angelo Daros de Luca authored 
      Schema changes:

- support for mdio-connected switches (mdio driver), recognized by
  checking the presence of property "reg"
- new compatible strings for rtl8367s and rtl8367rb
- "interrupt-controller" was not added as a required property. It might
  still work polling the ports when missing.

Examples changes:

- renamed "switch_intc" to make it unique between examples
- removed "dsa-mdio" from mdio compatible property
- renamed phy@0 to ethernet-phy@0 (not tested with real HW)
  phy@ requires #phy-cells
Signed-off-by: default avatarLuiz Angelo Daros de Luca <luizluca@gmail.com>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      429c83c7
    • Jakub Kicinski's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net · 5b91c5cc
      Jakub Kicinski authored 
      No conflicts.
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      5b91c5cc
    • Linus Torvalds's avatar
      Merge tag 'net-5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net · f1baf68e
      Linus Torvalds authored 
      Pull networking fixes from Jakub Kicinski:
 "Including fixes from netfilter and can.

Current release - new code bugs:

   - sparx5: fix get_stat64 out-of-bound access and crash

   - smc: fix netdev ref tracker misuse

  Previous releases - regressions:

   - eth: ixgbevf: require large buffers for build_skb on 82599VF, avoid
     overflows

   - eth: ocelot: fix all IP traffic getting trapped to CPU with PTP
     over IP

   - bonding: fix rare link activation misses in 802.3ad mode

  Previous releases - always broken:

   - tcp: fix tcp sock mem accounting in zero-copy corner cases

   - remove the cached dst when uncloning an skb dst and its metadata,
     since we only have one ref it'd lead to an UaF

   - netfilter:
      - conntrack: don't refresh sctp entries in closed state
      - conntrack: re-init state for retransmitted syn-ack, avoid
        connection establishment getting stuck with strange stacks
      - ctnetlink: disable helper autoassign, avoid it getting lost
      - nft_payload: don't allow transport header access for fragments

   - dsa: fix use of devres for mdio throughout drivers

   - eth: amd-xgbe: disable interrupts during pci removal

   - eth: dpaa2-eth: unregister netdev before disconnecting the PHY

   - eth: ice: fix IPIP and SIT TSO offload"

* tag 'net-5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (53 commits)
  net: dsa: mv88e6xxx: fix use-after-free in mv88e6xxx_mdios_unregister
  net: mscc: ocelot: fix mutex lock error during ethtool stats read
  ice: Avoid RTNL lock when re-creating auxiliary device
  ice: Fix KASAN error in LAG NETDEV_UNREGISTER handler
  ice: fix IPIP and SIT TSO offload
  ice: fix an error code in ice_cfg_phy_fec()
  net: mpls: Fix GCC 12 warning
  dpaa2-eth: unregister the netdev before disconnecting from the PHY
  skbuff: cleanup double word in comment
  net: macb: Align the dma and coherent dma masks
  mptcp: netlink: process IPv6 addrs in creating listening sockets
  selftests: mptcp: add missing join check
  net: usb: qmi_wwan: Add support for Dell DW5829e
  vlan: move dev_put into vlan_dev_uninit
  vlan: introduce vlan_dev_free_egress_priority
  ax25: fix UAF bugs of net_device caused by rebinding operation
  net: dsa: fix panic when DSA master device unbinds on shutdown
  net: amd-xgbe: disable interrupts during pci removal
  tipc: rate limit warning for received illegal binding update
  net: mdio: aspeed: Add missing MODULE_DEVICE_TABLE
  ...
      f1baf68e
  3. 10 Feb, 2022 32 commits
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