Petri Gynther [Wed, 1 Oct 2014 18:58:02 +0000 (11:58 -0700)]
net: phy: add BCM7425 and BCM7429 PHYs
Signed-off-by: Petri Gynther <pgynther@google.com> Acked-by: Florian Fainelli <f.fainelli@gmai.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Petri Gynther [Wed, 1 Oct 2014 18:30:01 +0000 (11:30 -0700)]
net: bcmgenet: fix bcmgenet_put_tx_csum()
bcmgenet_put_tx_csum() needs to return skb pointer back to the caller
because it reallocates a new one in case of lack of skb headroom.
Signed-off-by: Petri Gynther <pgynther@google.com> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This patch demonstrates the effect of delaying update of HW tailptr.
(based on earlier patch by Jesper)
burst=1 is the default. It sends one packet with xmit_more=false
burst=2 sends one packet with xmit_more=true and
2nd copy of the same packet with xmit_more=false
burst=3 sends two copies of the same packet with xmit_more=true and
3rd copy with xmit_more=false
Performance with ixgbe (usec 30):
burst=1 tx:9.2 Mpps
burst=2 tx:13.5 Mpps
burst=3 tx:14.5 Mpps full 10G line rate
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
In preparation for being able to propagate port states to e.g: notifiers
or other kernel parts, do not manipulate the port state directly, but
instead use a helper function which will allow us to do a bit more than
just setting the state.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
tp could be freed in call_rcu callback too, the order is not guaranteed.
John Fastabend says:
====================
Its worth noting why this is safe. Any running schedulers will either
read the valid class field or it will be zeroed.
All schedulers today when the class is 0 do a lookup using the
same call used by the tcf_exts_bind(). So even if we have a running
classifier hit the null class pointer it will do a lookup and get
to the same result. This is particularly fragile at the moment because
the only way to verify this is to audit the schedulers call sites.
====================
Cc: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
struct list_head can not be simply copied and we should always init it.
Cc: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller [Thu, 2 Oct 2014 01:35:58 +0000 (21:35 -0400)]
Merge branch 'udp_gso'
Tom Herbert says:
====================
udp: Generalize GSO for UDP tunnels
This patch set generalizes the UDP tunnel segmentation functions so
that they can work with various protocol encapsulations. The primary
change is to set the inner_protocol field in the skbuff when creating
the encapsulated packet, and then in skb_udp_tunnel_segment this data
is used to determine the function for segmenting the encapsulated
packet. The inner_protocol field is overloaded to take either an
Ethertype or IP protocol.
The inner_protocol is set on transmit using skb_set_inner_ipproto or
skb_set_inner_protocol functions. VXLAN and IP tunnels (for fou GSO)
were modified to call these.
Notes:
- GSO for GRE/UDP where GRE checksum is enabled does not work.
Handling this will require some special case code.
- Software GSO now supports many varieties of encapsulation with
SKB_GSO_UDP_TUNNEL{_CSUM}. We still need a mechanism to query
for device support of particular combinations (I intend to
add ndo_gso_check for that).
- MPLS seems to be the only previous user of inner_protocol. I don't
believe these patches can affect that. For supporting GSO with
MPLS over UDP, the inner_protocol should be set using the
helper functions in this patch.
- GSO for L2TP/UDP should also be straightforward now.
v2:
- Respin for Eric's restructuring of skbuff.
Tested GRE, IPIP, and SIT over fou as well as VLXAN. This was
done using 200 TCP_STREAMs in netperf.
GRE
IPv4, FOU, UDP checksum enabled
TCP_STREAM TSO enabled on tun interface
14.04% TX CPU utilization
13.17% RX CPU utilization
9211 Mbps
TCP_STREAM TSO disabled on tun interface
27.82% TX CPU utilization
25.41% RX CPU utilization
9336 Mbps
IPv4, FOU, UDP checksum disabled
TCP_STREAM TSO enabled on tun interface
13.14% TX CPU utilization
23.18% RX CPU utilization
9277 Mbps
TCP_STREAM TSO disabled on tun interface
30.00% TX CPU utilization
31.28% RX CPU utilization
9327 Mbps
IPIP
FOU, UDP checksum enabled
TCP_STREAM TSO enabled on tun interface
15.28% TX CPU utilization
13.92% RX CPU utilization
9342 Mbps
TCP_STREAM TSO disabled on tun interface
27.82% TX CPU utilization
25.41% RX CPU utilization
9336 Mbps
FOU, UDP checksum disabled
TCP_STREAM TSO enabled on tun interface
15.08% TX CPU utilization
24.64% RX CPU utilization
9226 Mbps
TCP_STREAM TSO disabled on tun interface
30.00% TX CPU utilization
31.28% RX CPU utilization
9327 Mbps
SIT
FOU, UDP checksum enabled
TCP_STREAM TSO enabled on tun interface
14.47% TX CPU utilization
14.58% RX CPU utilization
9106 Mbps
TCP_STREAM TSO disabled on tun interface
31.82% TX CPU utilization
30.82% RX CPU utilization
9204 Mbps
FOU, UDP checksum disabled
TCP_STREAM TSO enabled on tun interface
15.70% TX CPU utilization
27.93% RX CPU utilization
9097 Mbps
TCP_STREAM TSO disabled on tun interface
33.48% TX CPU utilization
37.36% RX CPU utilization
9197 Mbps
VXLAN
TCP_STREAM TSO enabled on tun interface
16.42% TX CPU utilization
23.66% RX CPU utilization
9081 Mbps
TCP_STREAM TSO disabled on tun interface
30.32% TX CPU utilization
30.55% RX CPU utilization
9185 Mbps
Baseline (no encp, TSO and LRO enabled)
TCP_STREAM
11.85% TX CPU utilization
15.13% RX CPU utilization
9452 Mbps
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Tom Herbert [Tue, 30 Sep 2014 03:22:32 +0000 (20:22 -0700)]
gre: Set inner protocol in v4 and v6 GRE transmit
Call skb_set_inner_protocol to set inner Ethernet protocol to
protocol being encapsulation by GRE before tunnel_xmit. This is
needed for GSO if UDP encapsulation (fou) is being done.
Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Tom Herbert [Tue, 30 Sep 2014 03:22:29 +0000 (20:22 -0700)]
udp: Generalize skb_udp_segment
skb_udp_segment is the function called from udp4_ufo_fragment to
segment a UDP tunnel packet. This function currently assumes
segmentation is transparent Ethernet bridging (i.e. VXLAN
encapsulation). This patch generalizes the function to
operate on either Ethertype or IP protocol.
The inner_protocol field must be set to the protocol of the inner
header. This can now be either an Ethertype or an IP protocol
(in a union). A new flag in the skbuff indicates which type is
effective. skb_set_inner_protocol and skb_set_inner_ipproto
helper functions were added to set the inner_protocol. These
functions are called from the point where the tunnel encapsulation
is occuring.
When skb_udp_tunnel_segment is called, the function to segment the
inner packet is selected based on the inner IP or Ethertype. In the
case of an IP protocol encapsulation, the function is derived from
inet[6]_offloads. In the case of Ethertype, skb->protocol is
set to the inner_protocol and skb_mac_gso_segment is called. (GRE
currently does this, but it might be possible to lookup the protocol
in offload_base and call the appropriate segmenation function
directly).
Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller [Thu, 2 Oct 2014 01:30:46 +0000 (21:30 -0400)]
Merge branch 'bpf-next'
Alexei Starovoitov says:
====================
bpf: add search pruning optimization and tests
patch #1 commit log explains why eBPF verifier has to examine some
instructions multiple times and describes the search pruning optimization
that improves verification speed for branchy programs and allows more
complex programs to be verified successfully.
This patch completes the core verifier logic.
patch #2 adds more verifier tests related to branches and search pruning
I'm still working on Andy's 'bitmask for stack slots' suggestion. It will be
done on top of this patch.
The current verifier algorithm is brute force depth first search with
state pruning. If anyone can come up with another algorithm that demonstrates
better results, we'll replace the algorithm without affecting user space.
Note verifier doesn't guarantee that all possible valid programs are accepted.
Overly complex programs may still be rejected.
Verifier improvements/optimizations will guarantee that if a program
was passing verification in the past, it will still be passing.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
consider C program represented in eBPF:
int filter(int arg)
{
int a, b, c, *ptr;
if (arg == 1)
ptr = &a;
else if (arg == 2)
ptr = &b;
else
ptr = &c;
*ptr = 0;
return 0;
}
eBPF verifier has to follow all possible paths through the program
to recognize that '*ptr = 0' instruction would be safe to execute
in all situations.
It's doing it by picking a path towards the end and observes changes
to registers and stack at every insn until it reaches bpf_exit.
Then it comes back to one of the previous branches and goes towards
the end again with potentially different values in registers.
When program has a lot of branches, the number of possible combinations
of branches is huge, so verifer has a hard limit of walking no more
than 32k instructions. This limit can be reached and complex (but valid)
programs could be rejected. Therefore it's important to recognize equivalent
verifier states to prune this depth first search.
Basic idea can be illustrated by the program (where .. are some eBPF insns):
1: ..
2: if (rX == rY) goto 4
3: ..
4: ..
5: ..
6: bpf_exit
In the first pass towards bpf_exit the verifier will walk insns: 1, 2, 3, 4, 5, 6
Since insn#2 is a branch the verifier will remember its state in verifier stack
to come back to it later.
Since insn#4 is marked as 'branch target', the verifier will remember its state
in explored_states[4] linked list.
Once it reaches insn#6 successfully it will pop the state recorded at insn#2 and
will continue.
Without search pruning optimization verifier would have to walk 4, 5, 6 again,
effectively simulating execution of insns 1, 2, 4, 5, 6
With search pruning it will check whether state at #4 after jumping from #2
is equivalent to one recorded in explored_states[4] during first pass.
If there is an equivalent state, verifier can prune the search at #4 and declare
this path to be safe as well.
In other words two states at #4 are equivalent if execution of 1, 2, 3, 4 insns
and 1, 2, 4 insns produces equivalent registers and stack.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Nimrod Andy [Tue, 30 Sep 2014 01:28:05 +0000 (09:28 +0800)]
net: fec: implement rx_copybreak to improve rx performance
- Copy short frames and keep the buffers mapped, re-allocate skb instead of
memory copy for long frames.
- Add support for setting/getting rx_copybreak using generic ethtool tunable
Changes V3:
* As Eric Dumazet's suggestion that removing the copybreak module parameter
and only keep the ethtool API support for rx_copybreak.
Changes V2:
* Implements rx_copybreak
* Rx_copybreak provides module parameter to change this value
* Add tunable_ops support for rx_copybreak
Signed-off-by: Fugang Duan <B38611@freescale.com> Signed-off-by: Frank Li <Frank.Li@freescale.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Francois Romieu <romieu@fr.zoreil.com> Cc: Hayes Wang <hayeswang@realtek.com> Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
tcp: abort orphan sockets stalling on zero window probes
Currently we have two different policies for orphan sockets
that repeatedly stall on zero window ACKs. If a socket gets
a zero window ACK when it is transmitting data, the RTO is
used to probe the window. The socket is aborted after roughly
tcp_orphan_retries() retries (as in tcp_write_timeout()).
But if the socket was idle when it received the zero window ACK,
and later wants to send more data, we use the probe timer to
probe the window. If the receiver always returns zero window ACKs,
icsk_probes keeps getting reset in tcp_ack() and the orphan socket
can stall forever until the system reaches the orphan limit (as
commented in tcp_probe_timer()). This opens up a simple attack
to create lots of hanging orphan sockets to burn the memory
and the CPU, as demonstrated in the recent netdev post "TCP
connection will hang in FIN_WAIT1 after closing if zero window is
advertised." http://www.spinics.net/lists/netdev/msg296539.html
This patch follows the design in RTO-based probe: we abort an orphan
socket stalling on zero window when the probe timer reaches both
the maximum backoff and the maximum RTO. For example, an 100ms RTT
connection will timeout after roughly 153 seconds (0.3 + 0.6 +
.... + 76.8) if the receiver keeps the window shut. If the orphan
socket passes this check, but the system already has too many orphans
(as in tcp_out_of_resources()), we still abort it but we'll also
send an RST packet as the connection may still be active.
In addition, we change TCP_USER_TIMEOUT to cover (life or dead)
sockets stalled on zero-window probes. This changes the semantics
of TCP_USER_TIMEOUT slightly because it previously only applies
when the socket has pending transmission.
Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Reported-by: Andrey Dmitrov <andrey.dmitrov@oktetlabs.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
Chun-Hao Lin [Wed, 1 Oct 2014 15:17:21 +0000 (23:17 +0800)]
r8169:call "rtl8168_driver_start" "rtl8168_driver_stop" only when hardware dash function is enabled
These two functions are used to inform dash firmware that driver is been
brought up or brought down. So call these two functions only when hardware dash
function is enabled.
Signed-off-by: Chun-Hao Lin <hau@realtek.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Chun-Hao Lin [Wed, 1 Oct 2014 15:17:20 +0000 (23:17 +0800)]
r8169:modify the behavior of function "rtl8168_oob_notify"
In function "rtl8168_oob_notify", using function "rtl_eri_write" to access
eri register 0xe8, instead of using MAC register "ERIDR" and "ERIAR" to
access it.
For using function "rtl_eri_write" in function "rtl8168_oob_notify", need to
move down "rtl8168_oob_notify" related functions under the function
"rtl_eri_write".
Signed-off-by: Chun-Hao Lin <hau@realtek.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Chun-Hao Lin [Wed, 1 Oct 2014 15:17:17 +0000 (23:17 +0800)]
r8169:for function "rtl_w1w0_phy" change its name and behavior
Change function name from "rtl_w1w0_phy" to "rtl_w0w1_phy".
And its behavior from "write ones then write zeros" to
"write zeros then write ones".
In Realtek internal driver, bitwise operations are almost "write zeros then
write ones". For easy to port hardware parameters from Realtek internal driver
to Linux kernal driver "r8169", we would like to change this function's
behavior and its name.
Signed-off-by: Chun-Hao Lin <hau@realtek.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Thierry Reding [Wed, 1 Oct 2014 11:59:00 +0000 (13:59 +0200)]
net: dsa: Fix build warning for !PM_SLEEP
The dsa_switch_suspend() and dsa_switch_resume() functions are only used
when PM_SLEEP is enabled, so they need #ifdef CONFIG_PM_SLEEP protection
to avoid a compiler warning.
Signed-off-by: Thierry Reding <treding@nvidia.com> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
net: ll_temac: Remove unnecessary ether_setup after alloc_etherdev
Calling ether_setup is redundant since alloc_etherdev calls it.
Signed-off-by: Subbaraya Sundeep Bhatta <sbhatta@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazet [Wed, 1 Oct 2014 05:12:05 +0000 (22:12 -0700)]
ipv4: mentions skb_gro_postpull_rcsum() in inet_gro_receive()
Proper CHECKSUM_COMPLETE support needs to adjust skb->csum
when we remove one header. Its done using skb_gro_postpull_rcsum()
In the case of IPv4, we know that the adjustment is not really needed,
because the checksum over IPv4 header is 0. Lets add a comment to
ease code comprehension and avoid copy/paste errors.
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
fm10k: using vmalloc requires including linux/vmalloc.h
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 3243acd37fd9
("ieee802154: add __init to lowpan_frags_sysctl_register")
added __init to lowpan_frags_ns_sysctl_register instead of
lowpan_frags_sysctl_register
Suggested-by: Alexander Aring <alex.aring@gmail.com> Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller [Tue, 30 Sep 2014 21:10:47 +0000 (17:10 -0400)]
Merge branch 'sunvnet-jumbograms'
David L Stevens says:
====================
sunvnet: add jumbo frames support
This patch set updates the sunvnet driver to version 1.6 of the VIO protocol
to support per-port exchange of MTU information and allow non-standard MTU
sizes, including jumbo frames.
Using large MTUs shows a nearly 5X throughput improvement Linux-Solaris
and > 10X throughput improvement Linux-Linux.
Changes from v8:
-add a short timeout to free pending skbs if a new transmit doesn't
do it first per Dave Miller <davem@davemloft.net>
Changes from v7:
-handle skb allocation failures in vnet_skb_shape()
per Dave Miller <davem@davemloft.net>
Changes from v6:
-made kernel transmit path zero-copy to remove memory n^2 scaling issue
raised by Raghuram Kothakota <Raghuram.Kothakota@oracle.com>
Changes from v5:
- fixed comment per Sowmini Varadhan <sowmini.varadhan@oracle.com>
Changes from v4:
- changed VNET_MAXPACKET per David Laight <David.Laight@ACULAB.COM>
- added cookies to support non-contiguous buffers of max size
Changes from v3:
- added version functions per Dave Miller <davem@davemloft.net>
- moved rmtu to vnet_port per Dave Miller <davem@davemloft.net>
- explicitly set options bits and capability flags to 0 per
Raghuram Kothakota <Raghuram.Kothakota@oracle.com>
Changes from v2:
- make checkpatch clean
Changes from v1:
- fix brace formatting per Dave Miller <davem@davemloft.net>
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
David L Stevens [Mon, 29 Sep 2014 23:48:24 +0000 (19:48 -0400)]
sunvnet: generate ICMP PTMUD messages for smaller port MTUs
This patch sends ICMP and ICMPv6 messages for Path MTU Discovery when a remote
port MTU is smaller than the device MTU. This allows mixing newer VIO protocol
devices that support MTU negotiation with older devices that do not on the
same vswitch. It also allows Linux-Linux LDOMs to use 64K-1 data packets even
though Solaris vswitch is limited to <16K MTU.
Signed-off-by: David L Stevens <david.stevens@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
David L Stevens [Mon, 29 Sep 2014 23:48:11 +0000 (19:48 -0400)]
sunvnet: make transmit path zero-copy in the kernel
This patch removes pre-allocated transmit buffers and instead directly maps
pending packets on demand. This saves O(n^2) maximum-sized transmit buffers,
for n hosts on a vswitch, as well as a copy to those buffers.
Single-stream TCP throughput linux-solaris dropped ~5% for 1500-byte MTU,
but linux-linux at 1500-bytes increased ~20%.
Signed-off-by: David L Stevens <david.stevens@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
David L Stevens [Mon, 29 Sep 2014 23:47:59 +0000 (19:47 -0400)]
sunvnet: upgrade to VIO protocol version 1.6
This patch upgrades the sunvnet driver to support VIO protocol version 1.6.
In particular, it adds per-port MTU negotiation, allowing MTUs other than
ETH_FRAMELEN with ports using newer VIO protocol versions.
Signed-off-by: David L Stevens <david.stevens@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
arch/mips/net/bpf_jit.c: In function 'build_body':
arch/mips/net/bpf_jit.c:762:6: error: unused variable 'tmp'
cc1: all warnings being treated as errors
make[2]: *** [arch/mips/net/bpf_jit.o] Error 1
Seen when building mips:allmodconfig in -next since next-20140924.
Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller [Tue, 30 Sep 2014 20:37:13 +0000 (16:37 -0400)]
Merge branch 'pxa168_eth'
Antoine Tenart says:
====================
ARM: Berlin: Ethernet support
This series introduce support for the Ethernet controller on Berlin SoCs,
using the existing pxa168 Ethernet driver. In order to do this, DT
support is added to the driver alongside some other modifications and
fixes.
This has been tested on a Berlin BG2Q DMP board.
Changes since v5:
- fixed the build when building the driver as a module
Changes since v4:
- removed the phy-addr property and added a phy subnode
- added COMPILE_TEST for the pxa168_eth driver
Changes since v3:
- moved the addition of pxa168_eth_get_mac_address() to the patch
using it first
Changes since v2:
- reworked how the MAC address is configured
- made the clock anonymous
Changes since v1:
- removed custom Berlin Ethernet driver
- used the pxa168 Ethernet driver instead
- made modifications to the pxa168 driver (DT support, fixes)
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
ARM: dts: berlin: enable the Ethernet port on the BG2Q DMP
This patch enables the Ethernet port on the Marvell Berlin2Q DMP board.
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds the Ethernet node, enabling the network unit on Berlin
BG2Q SoCs.
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
net: pxa168_eth: allow to compile the pxa168_eth driver for tests
Add a dependency to COMPILE_TEST so that the driver can be compiled for
test purposes.
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
net: pxa168_eth: allow Berlin SoCs to use the pxa168_eth driver
Berlin SoCs have an Ethernet controller compatible with the pxa168.
Allow these SoCs to use the pxa168_eth driver.
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
This patch rework the way the MAC address is retrieved. The MAC address
can now, in addition to being random, be set in the device tree or
retrieved from the Ethernet controller MAC address registers. The
probing function will try to get a MAC address in the following order:
- From the device tree.
- From the Ethernet controller MAC address registers.
- Generate a random one.
This patch also adds a function to read the MAC address from the
Ethernet Controller registers.
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
net: pxa168_eth: set the mac address on the Ethernet controller
When changing the MAC address, in addition to updating the dev_addr in
the net_device structure, this patch also update the MAC address
registers (high and low) of the Ethernet controller with the new MAC.
The address stored in these registers is used for IEEE 802.3x Ethernet
flow control, which is already enabled.
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
IEEE 802.3x Ethernet flow control is disabled when bit (1 << 2) is set
in the port status register. Fix the flow control detection in the link
event handling function which was relying on the opposite assumption.
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Documentation: bindings: net: add the Marvell PXA168 Ethernet controller
This adds the binding documentation for the Marvell PXA168 Ethernet
controller, following its DT support.
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Add the device tree support to the pxa168_eth driver.
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Clean up a bit the pxa168_eth driver before adding the device tree
support.
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Jack Morgenstein [Tue, 30 Sep 2014 09:03:50 +0000 (12:03 +0300)]
net/mlx4_core: Deprecate error message at ConnectX-2 cards startup to debug
ConnectX2 HCAs have max_mtu=4k and max_vl=8 vls. However, if you specify
a 4K mtu, the max_vl supported for 4K is 4 vls. The driver at startup
attempts to set a 4K mtu using the max_vl value obtained from QUERY_PORT.
Since the max_vl value is 8 vls (which is supported up to 2K mtu size),
the first attempt to set the mtl/vl port value will fail, generating
the following error message in the log:
mlx4_core 0000:06:00.0: command 0xc failed: fw status = 0x40
The driver then tries again, using mtu=4k, vls=4, and this succeeds.
Since we do not want to have this error message always displayed at driver
start when there are ConnectX2 HCAs on the host, we deprecate the error
message for this specific command/input_modifier/opcode_modifier/fw-status
to be debug.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Jack Morgenstein [Tue, 30 Sep 2014 09:03:49 +0000 (12:03 +0300)]
net/mlx4_core: Protect QUERY_PORT wrapper from untrusted guests
The function mlx4_QUERY_PORT_wrapper implements only the
QUERY_PORT "general" case (opcode modifier = 0).
Verify that the opcode modifier is zero, and also that the
input modifier contains only the port number in bits 0..7
(all other bits should be zero).
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Majd Dibbiny [Tue, 30 Sep 2014 09:03:48 +0000 (12:03 +0300)]
net/mlx4_core: New init and exit flow for mlx4_core
In the new flow, we separate the pci initialization and teardown
from the initialization and teardown of the other resources.
__mlx4_init_one handles the pci resources initialization. It then
calls mlx4_load_one to initialize the remainder of the resources.
When removing a device, mlx4_remove_one is invoked. However, now
mlx4_remove_one calls mlx4_unload_one to free all the resources except the pci
resources. When mlx4_unload_one returns, mlx4_remove_one then frees the
pci resources.
The above separation will allow us to implement 'reset flow' in the future.
It will also enable more EQs for VFs and is a pre-step to the modern API to
enable/disable SRIOV.
Also added nvfs; an integer array of size MLX4_MAX_PORTS + 1; to the mlx4_dev
struct. This new field is used to avoid parsing the num_vfs module parameter
each time the mlx4_restart_one is called.
Signed-off-by: Majd Dibbiny <majd@mellanox.com> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Jack Morgenstein [Tue, 30 Sep 2014 09:03:47 +0000 (12:03 +0300)]
net/mlx4_core: Don't disable SRIOV if there are active VFs
When unloading the host driver while there are VFs active on VMs,
the PF driver disabled sriov anyway, causing kernel crashes.
We now leave SRIOV enabled, to avoid that.
When the driver is reloaded, __mlx4_init_one is invoked on the PF.
It now checks to see if SRIOV is already enabled on the PF -- and
if so does not enable sriov again.
Signed-off-by: Tal Alon <talal@mellanox.com> Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
netfilter: bridge: build br_nf_core only if required
Eric reports build failure with
CONFIG_BRIDGE_NETFILTER=n
We insist to build br_nf_core.o unconditionally, but we must only do so
if br_netfilter was enabled, else it fails to build due to
functions being defined to empty stubs (and some structure members
being defined out).
Also, BRIDGE_NETFILTER=y|m makes no sense when BRIDGE=n.
Fixes: 34666d467 (netfilter: bridge: move br_netfilter out of the core) Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller [Tue, 30 Sep 2014 05:30:50 +0000 (01:30 -0400)]
Merge branch 'am335x'
Markus Pargmann says:
====================
net: cpsw: Support for am335x chip MACIDs
This series adds support to the cpsw driver to read the MACIDs of the am335x
chip and use them as fallback. These addresses are only used if there are no
mac addresses in the devicetree, for example set by a bootloader.
====================
Acked-by: Mugunthan V N <mugunthanvnm@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Markus Pargmann [Mon, 29 Sep 2014 06:53:19 +0000 (08:53 +0200)]
arm: dts: am33xx, Add syscon phandle to cpsw node
There are 2 MACIDs stored in the control module of the am33xx. These are
read by the cpsw driver if no valid MACID was found in the devicetree.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de> Reviewed-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Tony Lindgren <tony@atomide.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Markus Pargmann [Mon, 29 Sep 2014 06:53:18 +0000 (08:53 +0200)]
am33xx: define syscon control module device node
Signed-off-by: Markus Pargmann <mpa@pengutronix.de> Reviewed-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Tony Lindgren <tony@atomide.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Markus Pargmann [Mon, 29 Sep 2014 06:53:17 +0000 (08:53 +0200)]
net: cpsw: Add am33xx MACID readout
This patch adds a function to get the MACIDs from the am33xx SoC
control module registers which hold unique vendor MACIDs. This is only
used if of_get_mac_address() fails to get a valid mac address.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de> Reviewed-by: Wolfram Sang <wsa@the-dreams.de> Tested-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Tony Lindgren <tony@atomide.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Andy Gospodarek [Mon, 29 Sep 2014 02:34:37 +0000 (22:34 -0400)]
bonding: make global bonding stats more reliable
As the code stands today, bonding stats are based simply on the stats
from the member interfaces. If a member was to be removed from a bond,
the stats would instantly drop. This would be confusing to an admin
would would suddonly see interface stats drop while traffic is still
flowing.
In addition to preventing the stats drops mentioned above, new members
will now be added to the bond and only traffic received after the member
was added to the bond will be counted as part of bonding stats. Bonding
counters will also be updated when any slaves are dropped to make sure
the reported stats are reliable.
v2: Changes suggested by Nik to properly allocate/free stats memory.
v3: Properly destroy workqueue and fix netlink configuration path.
v4: Moved cached stats into bonding and slave structs as there does not
seem to be a complexity/performance benefit to using alloc'd memory vs
in-struct memory.
Signed-off-by: Andy Gospodarek <gospo@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
John Fastabend [Sun, 28 Sep 2014 18:53:57 +0000 (11:53 -0700)]
net: sched: restrict use of qstats qlen
This removes the use of qstats->qlen variable from the classifiers
and makes it an explicit argument to gnet_stats_copy_queue().
The qlen represents the qdisc queue length and is packed into
the qstats at the last moment before passnig to user space. By
handling it explicitely we avoid, in the percpu stats case, having
to figure out which per_cpu variable to put it in.
It would probably be best to remove it from qstats completely
but qstats is a user space ABI and can't be broken. A future
patch could make an internal only qstats structure that would
avoid having to allocate an additional u32 variable on the
Qdisc struct. This would make the qstats struct 128bits instead
of 128+32.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
John Fastabend [Sun, 28 Sep 2014 18:53:29 +0000 (11:53 -0700)]
net: sched: implement qstat helper routines
This adds helpers to manipulate qstats logic and replaces locations
that touch the counters directly. This simplifies future patches
to push qstats onto per cpu counters.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
John Fastabend [Sun, 28 Sep 2014 18:52:56 +0000 (11:52 -0700)]
net: sched: make bstats per cpu and estimator RCU safe
In order to run qdisc's without locking statistics and estimators
need to be handled correctly.
To resolve bstats make the statistics per cpu. And because this is
only needed for qdiscs that are running without locks which is not
the case for most qdiscs in the near future only create percpu
stats when qdiscs set the TCQ_F_CPUSTATS flag.
Next because estimators use the bstats to calculate packets per
second and bytes per second the estimator code paths are updated
to use the per cpu statistics.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Michael Braun [Thu, 25 Sep 2014 14:31:08 +0000 (16:31 +0200)]
macvlan: add source mode
This patch adds a new mode of operation to macvlan, called "source".
It allows one to set a list of allowed mac address, which is used
to match against source mac address from received frames on underlying
interface.
This enables creating mac based VLAN associations, instead of standard
port or tag based. The feature is useful to deploy 802.1x mac based
behavior, where drivers of underlying interfaces doesn't allows that.
Configuration is done through the netlink interface using e.g.:
ip link add link eth0 name macvlan0 type macvlan mode source
ip link add link eth0 name macvlan1 type macvlan mode source
ip link set link dev macvlan0 type macvlan macaddr add 00:11:11:11:11:11
ip link set link dev macvlan0 type macvlan macaddr add 00:22:22:22:22:22
ip link set link dev macvlan0 type macvlan macaddr add 00:33:33:33:33:33
ip link set link dev macvlan1 type macvlan macaddr add 00:33:33:33:33:33
ip link set link dev macvlan1 type macvlan macaddr add 00:44:44:44:44:44
This allows clients with MAC addresses 00:11:11:11:11:11,
00:22:22:22:22:22 to be part of only VLAN associated with macvlan0
interface. Clients with MAC addresses 00:44:44:44:44:44 with only VLAN
associated with macvlan1 interface. And client with MAC address
00:33:33:33:33:33 to be associated with both VLANs.
Based on work of Stefan Gula <steweg@gmail.com>
v8: last version of Stefan Gula for Kernel 3.2.1
v9: rework onto linux-next 2014-03-12 by Michael Braun
add MACADDR_SET command, enable to configure mac for source mode
while creating interface
v10:
- reduce indention level
- rename source_list to source_entry
- use aligned 64bit ether address
- use hash_64 instead of addr[5]
v11:
- rebase for 3.14 / linux-next 20.04.2014
v12
- rebase for linux-next 2014-09-25
Signed-off-by: Michael Braun <michael-dev@fami-braun.de> Signed-off-by: David S. Miller <davem@davemloft.net>
====================
pull request: netfilter/ipvs updates for net-next
The following patchset contains Netfilter/IPVS updates for net-next,
most relevantly they are:
1) Four patches to make the new nf_tables masquerading support
independent of the x_tables infrastructure. This also resolves a
compilation breakage if the masquerade target is disabled but the
nf_tables masq expression is enabled.
2) ipset updates via Jozsef Kadlecsik. This includes the addition of the
skbinfo extension that allows you to store packet metainformation in the
elements. This can be used to fetch and restore this to the packets through
the iptables SET target, patches from Anton Danilov.
3) Add the hash:mac set type to ipset, from Jozsef Kadlecsick.
4) Add simple weighted fail-over scheduler via Simon Horman. This provides
a fail-over IPVS scheduler (unlike existing load balancing schedulers).
Connections are directed to the appropriate server based solely on
highest weight value and server availability, patch from Kenny Mathis.
5) Support IPv6 real servers in IPv4 virtual-services and vice versa.
Simon Horman informs that the motivation for this is to allow more
flexibility in the choice of IP version offered by both virtual-servers
and real-servers as they no longer need to match: An IPv4 connection
from an end-user may be forwarded to a real-server using IPv6 and
vice versa. No ip_vs_sync support yet though. Patches from Alex Gartrell
and Julian Anastasov.
6) Add global generation ID to the nf_tables ruleset. When dumping from
several different object lists, we need a way to identify that an update
has ocurred so userspace knows that it needs to refresh its lists. This
also includes a new command to obtain the 32-bits generation ID. The
less significant 16-bits of this ID is also exposed through res_id field
in the nfnetlink header to quickly detect the interference and retry when
there is no risk of ID wraparound.
7) Move br_netfilter out of the bridge core. The br_netfilter code is
built in the bridge core by default. This causes problems of different
kind to people that don't want this: Jesper reported performance drop due
to the inconditional hook registration and I remember to have read complains
on netdev from people regarding the unexpected behaviour of our bridging
stack when br_netfilter is enabled (fragmentation handling, layer 3 and
upper inspection). People that still need this should easily undo the
damage by modprobing the new br_netfilter module.
8) Dump the set policy nf_tables that allows set parameterization. So
userspace can keep user-defined preferences when saving the ruleset.
From Arturo Borrero.
9) Use __seq_open_private() helper function to reduce boiler plate code
in x_tables, From Rob Jones.
10) Safer default behaviour in case that you forget to load the protocol
tracker. Daniel Borkmann and Florian Westphal detected that if your
ruleset is stateful, you allow traffic to at least one single SCTP port
and the SCTP protocol tracker is not loaded, then any SCTP traffic may
be pass through unfiltered. After this patch, the connection tracking
classifies SCTP/DCCP/UDPlite/GRE packets as invalid if your kernel has
been compiled with support for these modules.
====================
Trivially resolved conflict in include/linux/skbuff.h, Eric moved some
netfilter skbuff members around, and the netfilter tree adjusted the
ifdef guards for the bridging info pointer.
Signed-off-by: David S. Miller <davem@davemloft.net>
Suggested by Stephen. Also drop inline keyword and let compiler decide.
gcc 4.7.3 decides to no longer inline tcp_ecn_check_ce, so split it up.
The actual evaluation is not inlined anymore while the ECN_OK test is.
Suggested-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
After Octavian Purdilas tcp ipv4/ipv6 unification work this helper only
has a single callsite.
While at it, convert name to lowercase, suggested by Stephen.
Suggested-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller [Mon, 29 Sep 2014 18:36:33 +0000 (14:36 -0400)]
Merge branch 'arcnet-EAE'
Michael Grzeschik says:
====================
ARCNET: add support for EAE multi interfac card
this series adds support for the PLX Bridge based multi interface
pci cards and adds support to change device address on com200xx chips
during runtime.
This series is based on v3.17-rc7.
It is fixed for build against com20020_cs.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
ARCNET: add support for multi interfaces on com20020
The com20020-pci driver is currently designed to instance
one netdev with one pci device. This patch adds support to
instance many cards with one pci device, depending on the device
data in the private data.
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
ARCNET: return IRQ_NONE if the interface isn't running
The interrupt handler needs to return IRQ_NONE in case
two devices are used with the shared interrupt handler.
Otherwise it could steal interrupts from the other
interface.
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazet [Mon, 29 Sep 2014 05:18:47 +0000 (22:18 -0700)]
net: reorganize sk_buff for faster __copy_skb_header()
With proliferation of bit fields in sk_buff, __copy_skb_header() became
quite expensive, showing as the most expensive function in a GSO
workload.
__copy_skb_header() performance is also critical for non GSO TCP
operations, as it is used from skb_clone()
This patch carefully moves all the fields that were not copied in a
separate zone : cloned, nohdr, fclone, peeked, head_frag, xmit_more
Then I moved all other fields and all other copied fields in a section
delimited by headers_start[0]/headers_end[0] section so that we
can use a single memcpy() call, inlined by compiler using long
word load/stores.
I also tried to make all copies in the natural orders of sk_buff,
to help hardware prefetching.
I made sure sk_buff size did not change.
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
netfilter: conntrack: disable generic tracking for known protocols
Given following iptables ruleset:
-P FORWARD DROP
-A FORWARD -m sctp --dport 9 -j ACCEPT
-A FORWARD -p tcp --dport 80 -j ACCEPT
-A FORWARD -p tcp -m conntrack -m state ESTABLISHED,RELATED -j ACCEPT
One would assume that this allows SCTP on port 9 and TCP on port 80.
Unfortunately, if the SCTP conntrack module is not loaded, this allows
*all* SCTP communication, to pass though, i.e. -p sctp -j ACCEPT,
which we think is a security issue.
This is because on the first SCTP packet on port 9, we create a dummy
"generic l4" conntrack entry without any port information (since
conntrack doesn't know how to extract this information).
All subsequent packets that are unknown will then be in established
state since they will fallback to proto_generic and will match the
'generic' entry.
Our originally proposed version [1] completely disabled generic protocol
tracking, but Jozsef suggests to not track protocols for which a more
suitable helper is available, hence we now mitigate the issue for in
tree known ct protocol helpers only, so that at least NAT and direction
information will still be preserved for others.
This patch series adds support for the Qualcomm QCA7000 Homeplug GreenPHY.
The QCA7000 is serial-to-powerline bridge with two interfaces: UART and SPI.
These patches handles only the last one, with an Ethernet over SPI protocol
driver.
This driver based on the Qualcomm code [1], but contains a lot of changes
since last year:
* devicetree support
* DebugFS support
* ethtool support
* better error handling
* performance improvements
* code cleanup
* some bugfixes
The code has been tested only on Freescale i.MX28 boards, but should work
on other platforms.
[1] - https://github.com/IoE/qca7000
Changes in V3:
- Use ether_addr_copy instead of memcpy
- Remove qcaspi_set_mac_address
- Improve DT parsing
- replace OF_GPIO dependancy with OF
- fix compile error caused by SET_ETHTOOL_OPS
- fix possible endless loop when spi read fails
- fix DT documentation
- fix coding style
- fix sparse warnings
Changes in V2:
- replace in DT the SPI intr GPIO with pure interrupt
- make legacy mode a boolean DT property and remove it as module parameter
- make burst length a module parameter instead of DT property
- make pluggable a module parameter instead of DT property
- improve DT documentation
- replace debugFS register dump with ethtool function
- replace debugFS stats with ethtool function
- implement function to get ring parameter via ethtool
- implement function to set TX ring count via ethtool
- fix TX ring state in debugFS
- optimize tx ring flush
- add byte limit for TX ring to avoid bufferbloat
- fix TX queue full and write buffer miss counter
- fix SPI clk speed module parameter
- fix possible packet loss
- fix possible race during transmit
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller [Mon, 29 Sep 2014 04:13:17 +0000 (00:13 -0400)]
Merge branch 'dctcp'
Daniel Borkmann says:
====================
net: tcp: DCTCP congestion control algorithm
This patch series adds support for the DataCenter TCP (DCTCP) congestion
control algorithm. Please see individual patches for the details.
The last patch adds DCTCP as a congestion control module, and previous
ones add needed infrastructure to extend the congestion control framework.
Joint work between Florian Westphal, Daniel Borkmann and Glenn Judd.
v3 -> v2:
- No changes anywhere, just a resend as requested by Dave
- Added Stephen's ACK
v1 -> v2:
- Rebased to latest net-next
- Addressed Eric's feedback, thanks!
- Update stale comment wrt. DCTCP ECN usage
- Don't call INET_ECN_xmit for every packet
- Add dctcp ss/inetdiag support to expose internal stats to userspace
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Daniel Borkmann [Fri, 26 Sep 2014 20:37:36 +0000 (22:37 +0200)]
net: tcp: add DCTCP congestion control algorithm
This work adds the DataCenter TCP (DCTCP) congestion control
algorithm [1], which has been first published at SIGCOMM 2010 [2],
resp. follow-up analysis at SIGMETRICS 2011 [3] (and also, more
recently as an informational IETF draft available at [4]).
DCTCP is an enhancement to the TCP congestion control algorithm for
data center networks. Typical data center workloads are i.e.
i) partition/aggregate (queries; bursty, delay sensitive), ii) short
messages e.g. 50KB-1MB (for coordination and control state; delay
sensitive), and iii) large flows e.g. 1MB-100MB (data update;
throughput sensitive). DCTCP has therefore been designed for such
environments to provide/achieve the following three requirements:
* High burst tolerance (incast due to partition/aggregate)
* Low latency (short flows, queries)
* High throughput (continuous data updates, large file
transfers) with commodity, shallow buffered switches
The basic idea of its design consists of two fundamentals: i) on the
switch side, packets are being marked when its internal queue
length > threshold K (K is chosen so that a large enough headroom
for marked traffic is still available in the switch queue); ii) the
sender/host side maintains a moving average of the fraction of marked
packets, so each RTT, F is being updated as follows:
F := X / Y, where X is # of marked ACKs, Y is total # of ACKs
alpha := (1 - g) * alpha + g * F, where g is a smoothing constant
The resulting alpha (iow: probability that switch queue is congested)
is then being used in order to adaptively decrease the congestion
window W:
W := (1 - (alpha / 2)) * W
The means for receiving marked packets resp. marking them on switch
side in DCTCP is the use of ECN.
RFC3168 describes a mechanism for using Explicit Congestion Notification
from the switch for early detection of congestion, rather than waiting
for segment loss to occur.
However, this method only detects the presence of congestion, not
the *extent*. In the presence of mild congestion, it reduces the TCP
congestion window too aggressively and unnecessarily affects the
throughput of long flows [4].
DCTCP, as mentioned, enhances Explicit Congestion Notification (ECN)
processing to estimate the fraction of bytes that encounter congestion,
rather than simply detecting that some congestion has occurred. DCTCP
then scales the TCP congestion window based on this estimate [4],
thus it can derive multibit feedback from the information present in
the single-bit sequence of marks in its control law. And thus act in
*proportion* to the extent of congestion, not its *presence*.
Switches therefore set the Congestion Experienced (CE) codepoint in
packets when internal queue lengths exceed threshold K. Resulting,
DCTCP delivers the same or better throughput than normal TCP, while
using 90% less buffer space.
It was found in [2] that DCTCP enables the applications to handle 10x
the current background traffic, without impacting foreground traffic.
Moreover, a 10x increase in foreground traffic did not cause any
timeouts, and thus largely eliminates TCP incast collapse problems.
The algorithm itself has already seen deployments in large production
data centers since then.
We did a long-term stress-test and analysis in a data center, short
summary of our TCP incast tests with iperf compared to cubic:
This test measured DCTCP throughput and latency and compared it with
CUBIC throughput and latency for an incast scenario. In this test, 19
senders sent at maximum rate to a single receiver. The receiver simply
ran iperf -s.
The senders ran iperf -c <receiver> -t 30. All senders started
simultaneously (using local clocks synchronized by ntp).
This test was repeated multiple times. Below shows the results from a
single test. Other tests are similar. (DCTCP results were extremely
consistent, CUBIC results show some variance induced by the TCP timeouts
that CUBIC encountered.)
For this test, we report statistics on the number of TCP timeouts,
flow throughput, and traffic latency.
1) Timeouts (total over all flows, and per flow summaries):
CUBIC DCTCP
Total 3227 25
Mean 169.842 1.316
Median 183 1
Max 207 5
Min 123 0
Stddev 28.991 1.600
Timeout data is taken by measuring the net change in netstat -s
"other TCP timeouts" reported. As a result, the timeout measurements
above are not restricted to the test traffic, and we believe that it
is likely that all of the "DCTCP timeouts" are actually timeouts for
non-test traffic. We report them nevertheless. CUBIC will also include
some non-test timeouts, but they are drawfed by bona fide test traffic
timeouts for CUBIC. Clearly DCTCP does an excellent job of preventing
TCP timeouts. DCTCP reduces timeouts by at least two orders of
magnitude and may well have eliminated them in this scenario.
2) Throughput (per flow in Mbps):
CUBIC DCTCP
Mean 521.684 521.895
Median 464 523
Max 776 527
Min 403 519
Stddev 105.891 2.601
Fairness 0.962 0.999
Throughput data was simply the average throughput for each flow
reported by iperf. By avoiding TCP timeouts, DCTCP is able to
achieve much better per-flow results. In CUBIC, many flows
experience TCP timeouts which makes flow throughput unpredictable and
unfair. DCTCP, on the other hand, provides very clean predictable
throughput without incurring TCP timeouts. Thus, the standard deviation
of CUBIC throughput is dramatically higher than the standard deviation
of DCTCP throughput.
Mean throughput is nearly identical because even though cubic flows
suffer TCP timeouts, other flows will step in and fill the unused
bandwidth. Note that this test is something of a best case scenario
for incast under CUBIC: it allows other flows to fill in for flows
experiencing a timeout. Under situations where the receiver is issuing
requests and then waiting for all flows to complete, flows cannot fill
in for timed out flows and throughput will drop dramatically.
3) Latency (in ms):
CUBIC DCTCP
Mean 4.0088 0.04219
Median 4.055 0.0395
Max 4.2 0.085
Min 3.32 0.028
Stddev 0.1666 0.01064
Latency for each protocol was computed by running "ping -i 0.2
<receiver>" from a single sender to the receiver during the incast
test. For DCTCP, "ping -Q 0x6 -i 0.2 <receiver>" was used to ensure
that traffic traversed the DCTCP queue and was not dropped when the
queue size was greater than the marking threshold. The summary
statistics above are over all ping metrics measured between the single
sender, receiver pair.
The latency results for this test show a dramatic difference between
CUBIC and DCTCP. CUBIC intentionally overflows the switch buffer
which incurs the maximum queue latency (more buffer memory will lead
to high latency.) DCTCP, on the other hand, deliberately attempts to
keep queue occupancy low. The result is a two orders of magnitude
reduction of latency with DCTCP - even with a switch with relatively
little RAM. Switches with larger amounts of RAM will incur increasing
amounts of latency for CUBIC, but not for DCTCP.
4) Convergence and stability test:
This test measured the time that DCTCP took to fairly redistribute
bandwidth when a new flow commences. It also measured DCTCP's ability
to remain stable at a fair bandwidth distribution. DCTCP is compared
with CUBIC for this test.
At the commencement of this test, a single flow is sending at maximum
rate (near 10 Gbps) to a single receiver. One second after that first
flow commences, a new flow from a distinct server begins sending to
the same receiver as the first flow. After the second flow has sent
data for 10 seconds, the second flow is terminated. The first flow
sends for an additional second. Ideally, the bandwidth would be evenly
shared as soon as the second flow starts, and recover as soon as it
stops.
The results of this test are shown below. Note that the flow bandwidth
for the two flows was measured near the same time, but not
simultaneously.
DCTCP performs nearly perfectly within the measurement limitations
of this test: bandwidth is quickly distributed fairly between the two
flows, remains stable throughout the duration of the test, and
recovers quickly. CUBIC, in contrast, is slow to divide the bandwidth
fairly, and has trouble remaining stable.
This test demonstrates the importance of ECT on SYN and SYN-ACK packets
by measuring the connection probability in the presence of competing
flows for a DCTCP connection attempt *without* ECT in the SYN packet.
The test was repeated five times for each number of competing flows.
Competing Flows 1 | 2 | 4 | 8 | 16
------------------------------
Mean Connection Probability 1 | 0.67 | 0.45 | 0.28 | 0
Median Connection Probability 1 | 0.65 | 0.45 | 0.25 | 0
As the number of competing flows moves beyond 1, the connection
probability drops rapidly.
Enabling DCTCP with this patch requires the following steps:
DCTCP must be running both on the sender and receiver side in your
data center, i.e.:
sysctl -w net.ipv4.tcp_congestion_control=dctcp
Also, ECN functionality must be enabled on all switches in your
data center for DCTCP to work. The default ECN marking threshold (K)
heuristic on the switch for DCTCP is e.g., 20 packets (30KB) at
1Gbps, and 65 packets (~100KB) at 10Gbps (K > 1/7 * C * RTT, [4]).
In above tests, for each switch port, traffic was segregated into two
queues. For any packet with a DSCP of 0x01 - or equivalently a TOS of
0x04 - the packet was placed into the DCTCP queue. All other packets
were placed into the default drop-tail queue. For the DCTCP queue,
RED/ECN marking was enabled, here, with a marking threshold of 75 KB.
More details however, we refer you to the paper [2] under section 3).
There are no code changes required to applications running in user
space. DCTCP has been implemented in full *isolation* of the rest of
the TCP code as its own congestion control module, so that it can run
without a need to expose code to the core of the TCP stack, and thus
nothing changes for non-DCTCP users.
Changes in the CA framework code are minimal, and DCTCP algorithm
operates on mechanisms that are already available in most Silicon.
The gain (dctcp_shift_g) is currently a fixed constant (1/16) from
the paper, but we leave the option that it can be chosen carefully
to a different value by the user.
In case DCTCP is being used and ECN support on peer site is off,
DCTCP falls back after 3WHS to operate in normal TCP Reno mode.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Glenn Judd <glenn.judd@morganstanley.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
net: tcp: more detailed ACK events and events for CE marked packets
DataCenter TCP (DCTCP) determines cwnd growth based on ECN information
and ACK properties, e.g. ACK that updates window is treated differently
than DUPACK.
Also DCTCP needs information whether ACK was delayed ACK. Furthermore,
DCTCP also implements a CE state machine that keeps track of CE markings
of incoming packets.
Therefore, extend the congestion control framework to provide these
event types, so that DCTCP can be properly implemented as a normal
congestion algorithm module outside of the core stack.
Joint work with Daniel Borkmann and Glenn Judd.
Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Glenn Judd <glenn.judd@morganstanley.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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