Implementing the advanced early retransmit (sysctl_tcp_early_retrans==2).
Delays the fast retransmit by an interval of RTT/4. We borrow the
RTO timer to implement the delay. If we receive another ACK or send
a new packet, the timer is cancelled and restored to original RTO
value offset by time elapsed. When the delayed-ER timer fires,
we enter fast recovery and perform fast retransmit.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch implements RFC 5827 early retransmit (ER) for TCP.
It reduces DUPACK threshold (dupthresh) if outstanding packets are
less than 4 to recover losses by fast recovery instead of timeout.
While the algorithm is simple, small but frequent network reordering
makes this feature dangerous: the connection repeatedly enter
false recovery and degrade performance. Therefore we implement
a mitigation suggested in the appendix of the RFC that delays
entering fast recovery by a small interval, i.e., RTT/4. Currently
ER is conservative and is disabled for the rest of the connection
after the first reordering event. A large scale web server
experiment on the performance impact of ER is summarized in
section 6 of the paper "Proportional Rate Reduction for TCP”,
IMC 2011. http://conferences.sigcomm.org/imc/2011/docs/p155.pdf
Note that Linux has a similar feature called THIN_DUPACK. The
differences are THIN_DUPACK do not mitigate reorderings and is only
used after slow start. Currently ER is disabled if THIN_DUPACK is
enabled. I would be happy to merge THIN_DUPACK feature with ER if
people think it's a good idea.
ER is enabled by sysctl_tcp_early_retrans:
0: Disables ER
1: Reduce dupthresh to packets_out - 1 when outstanding packets < 4.
2: (Default) reduce dupthresh like mode 1. In addition, delay
entering fast recovery by RTT/4.
Note: mode 2 is implemented in the third part of this patch series.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This a prepartion patch that refactors the code to enter recovery
into a new function tcp_enter_recovery(). It's needed to implement
the delayed fast retransmit in ER.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix this compiler warning (on PowerPC) by not marking a parameter as
const:
drivers/net/ethernet/pasemi/pasemi_mac.c: In function 'pasemi_mac_replenish_rx_ring':
drivers/net/ethernet/pasemi/pasemi_mac.c:646:3: warning: passing argument 1 of 'netdev_alloc_skb' discards qualifiers from pointer target type
include/linux/skbuff.h:1706:31: note: expected 'struct net_device *' but argument is of type 'const struct net_device *'
Cc: Olof Johansson <olof@lixom.net>
Cc: Pradeep A. Dalvi <netdev@pradeepdalvi.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
If the user request for the number of VFs in the max_vfs parameter is
out of range then reset the value to the default value of zero. This
makes the behavior of the ixgbe driver the same as for the igb driver.
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Robert Garrett <robertx.e.garrett@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Some 82599 adapters contain thermal data that we can get to via
an i2c interface. These functions provide support to get at that
data. A following patch will export this data.
Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Secondary unicast and multicast addresses are added to the Receive
Address registers (RAR) for most parts supported by the driver. For
82579, there is only one actual RAR and a number of Shared Receive Address
registers (SHRAR) that are shared among the driver and f/w which can be
reserved and write-protected by the f/w. On this device, use the SHRARs
that are not taken by f/w for the additional addresses.
Add a MAC ops function pointer infrastructure (similar to other MAC
operations in the driver) for setting RARs, introduce a new rar_set
function for 82579 and convert the existing code that sets RARs on other
devices to a generic rar_set function.
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
The PHY initialization flows and assorted workarounds for 82577/8/9 done
during driver load and resume from Sx should be the same yet they are not.
Combine the current flows/workarounds into a common set of functions that
are called during the different code paths.
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
An update to the EEPROM on 82579 will extend a delay in hardware to fix an
issue with WoL not working after a G3->S5 transition which is unrelated to
the driver. However, this extended delay conflicts with nominal operation
of the device when it is initialized by the driver and after every reset
of the hardware (i.e. the driver starts configuring the device before the
hardware is done with it's own configuration work). The workaround for
when the driver is in control of the device is to tell the hardware after
every reset the configuration delay should be the original shorter one.
Some pre-existing variables are renamed generically to be re-used with
new register accesses.
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
remove useless casts and rename variables for less confusion.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
TCP or UDP stacks have big enough latencies that prefetching next
pointer is worth it.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The netlink API lets users create unmanaged L2TPv3 tunnels using
iproute2. Until now, a request to create an unmanaged L2TPv3 IP
encapsulation tunnel over IPv6 would be rejected with
EPROTONOSUPPORT. Now that l2tp_ip6 implements sockets for L2TP IP
encapsulation over IPv6, we can add support for that tunnel type.
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
L2TPv3 defines an IP encapsulation packet format where data is carried
directly over IP (no UDP). The kernel already has support for L2TP IP
encapsulation over IPv4 (l2tp_ip). This patch introduces support for
L2TP IP encapsulation over IPv6.
The implementation is derived from ipv6/raw and ipv4/l2tp_ip.
Signed-off-by: Chris Elston <celston@katalix.com>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For implementing other protocols on top of IPv6, such as L2TPv3's IP
encapsulation over ipv6, we'd like to call some IPv6 functions which
are not currently exported. This patch exports them.
Signed-off-by: Chris Elston <celston@katalix.com>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds support for unmanaged L2TPv3 tunnels over IPv6 using
the netlink API. We already support unmanaged L2TPv3 tunnels over
IPv4. A patch to iproute2 to make use of this feature will be
submitted separately.
Signed-off-by: Chris Elston <celston@katalix.com>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If an L2TP tunnel uses IPv6, make sure the l2tp debugfs file shows the
IPv6 address correctly.
Signed-off-by: Chris Elston <celston@katalix.com>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Userspace uses connect() to associate a pppol2tp socket with a tunnel
socket. This needs to allow the caller to supply the new IPv6
sockaddr_pppol2tp structures if IPv6 is used.
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Checkpatch warns about the use of __attribute__((packed)). So use the
recommended __packed syntax instead.
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The l2tp_ip socket currently maintains packet/byte stats in its
private socket structure. But these counters aren't exposed to
userspace and so serve no purpose. The counters were also
smp-unsafe. So this patch just gets rid of the stats.
While here, change a couple of internal __u32 variables to u32.
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cleanup the l2tp_ip code to make use of an existing ipv4 support function.
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
L2TP uses 64-bit counters but since these are not updated atomically,
we need to make them safe for smp. This patch addresses that.
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
