Currently netem is not in the ability to emulate channel bandwidth. Only static
delay (and optional random jitter) can be configured.

To emulate the channel rate the token bucket filter (sch_tbf) can be used.  But
TBF has some major emulation flaws. The buffer (token bucket depth/rate) cannot
be 0. Also the idea behind TBF is that the credit (token in buckets) fills if
no packet is transmitted. So that there is always a "positive" credit for new
packets. In real life this behavior contradicts the law of nature where
nothing can travel faster as speed of light. E.g.: on an emulated 1000 byte/s
link a small IPv4/TCP SYN packet with ~50 byte require ~0.05 seconds - not 0
seconds.

Netem is an excellent place to implement a rate limiting feature: static
delay is already implemented, tfifo already has time information and the
user can skip TBF configuration completely.

This patch implement rate feature which can be configured via tc. e.g:

	tc qdisc add dev eth0 root netem rate 10kbit

To emulate a link of 5000byte/s and add an additional static delay of 10ms:

	tc qdisc add dev eth0 root netem delay 10ms rate 5KBps

Note: similar to TBF the rate extension is bounded to the kernel timing
system. Depending on the architecture timer granularity, higher rates (e.g.
10mbit/s and higher) tend to transmission bursts. Also note: further queues
living in network adaptors; see ethtool(8).
Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@drr.davemloft.net>

Need not to used 'delta' flag when add single-source to interface
filter source list.
Signed-off-by: Jun Zhao <mypopydev@gmail.com>
Signed-off-by: David S. Miller <davem@drr.davemloft.net>

Need not to used 'delta' flag when add single-source to interface
filter source list.
Signed-off-by: Jun Zhao <mypopydev@gmail.com>
Signed-off-by: David S. Miller <davem@drr.davemloft.net>

Instead of instantiating an entire new neigh_table instance
just for ATM handling, use the neigh device private facility.
Signed-off-by: David S. Miller <davem@davemloft.net>

If the neigh entry has device private state, it will need
constructor/destructor ops.
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: David S. Miller <davem@davemloft.net>

Let the core self-size the neigh entry based upon the key length.
Signed-off-by: David S. Miller <davem@davemloft.net>

netdev->neigh_priv_len records the private area length.

This will trigger for neigh_table objects which set tbl->entry_size
to zero, and the first instances of this will be forthcoming.
Signed-off-by: David S. Miller <davem@davemloft.net>

We are going to alloc for device specific private areas for
neighbour entries, and in order to do that we have to move
away from the fixed allocation size enforced by using
neigh_table->kmem_cachep

As a nice side effect we can now use kfree_rcu().
Signed-off-by: David S. Miller <davem@davemloft.net>

The implementation private sits right after the primary_key memory.
Signed-off-by: David S. Miller <davem@davemloft.net>

As soon as skb is pushed to hardware, it can be completed and freed, so
we should not dereference skb anymore.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Changes to bnx2 to use byte queue limits.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Rick Jones reported that TCP_CONGESTION sockopt performed on a listener
was ignored for its children sockets : right after accept() the
congestion control for new socket is the system default one.

This seems an oversight of the initial design (quoted from Stephen)

Based on prior investigation and patch from Rick.
Reported-by: Rick Jones <rick.jones2@hp.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Stephen Hemminger <shemminger@vyatta.com>
CC: Yuchung Cheng <ycheng@google.com>
Tested-by: Rick Jones <rick.jones2@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Newer versions have been floating about, and I applied
to older variant unfortunately.
Signed-off-by: David S. Miller <davem@davemloft.net>

This adds support for byte queue limits and aggregates statistics
update (suggestion from Eric).
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@drr.davemloft.net>

in iSCSI SD mode to bnx2x device assigned single mac address
which is supposted to be iscsi mac. If this mode is recognized
bnx2x will disable LRO, decrease number of queues to 1 and rx ring
size to the minumum allowed by FW, this in order minimize memory use.
It will tranfer mac for iscsi usage and zero primary mac of the netdev.
Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch adds support for legacy Bosch CC770 and Intel AN82527 CAN
controllers on the ISA or PC-104 bus. The I/O port or memory address
and the IRQ number must be specified via module parameters:

  insmod cc770_isa.ko port=0x310,0x380 irq=7,11

for ISA devices using I/O ports or:

  insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11

for memory mapped ISA devices.

Indirect access via address and data port is supported as well:

  insmod cc770_isa.ko port=0x310,0x380 indirect=1 irq=7,11

Furthermore, the following mode parameter can be defined:

  clk: External oscillator clock frequency (default=16000000 [16 MHz])
  cir: CPU interface register (default=0x40 [CPU_DSC])
  ocr, Bus configuration register (default=0x00)
  cor, Clockout register (default=0x00)

Note: for clk, cir, bcr and cor, the first argument re-defines the
default for all other devices, e.g.:

  insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11 clk=24000000

is equivalent to

  insmod cc770_isa.ko mem=0xd1000,0xd1000 irq=7,11 clk=24000000,24000000
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add some basic regulator support for the power pins, as needed
by the ST-Ericsson Snowball platform that powers up the SMSC911
chip using an external regulator.

Platforms that use regulators and the smsc911x and have no defined
regulator for the smsc911x and claim complete regulator
constraints with no dummy regulators will need to provide it, for
example using a fixed voltage regulator. It appears that this may
affect (apart from Ux500 Snowball) possibly these archs/machines
that from some grep:s appear to define both CONFIG_SMSC911X and
CONFIG_REGULATOR:

- ARM Freescale mx3 and OMAP 2 plus, Raumfeld machines
- Blackfin
- Super-H

Cc: Paul Mundt <lethal@linux-sh.org>
Cc: linux-sh@vger.kernel.org
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Tony Lindgren <tony@atomide.com>
Cc: linux-omap@vger.kernel.org
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: uclinux-dist-devel@blackfin.uclinux.org
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Robert Marklund <robert.marklund@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

This driver is currently not supported on x86_64 systems because the
"isa_driver" interface is used (CONFIG_ISA=y). To overcome this
limitation, the driver is converted to a platform driver, similar to
the serial 8250 driver.
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 7dc00c82 added a 'notify' parameter for vif_delete() to
distinguish whether to unregister the device.

When notify=1 means we does not need to unregister the device,
so calling unregister_netdevice_many is useless.
Signed-off-by: RongQing.Li <roy.qing.li@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fixes the compiler warnings: "comparison is always
false due to limited range of data type" by using "0xff" instead
of "-1" for unsigned values.
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Change function rcu_dereference to rcu_dereference_bh to avoid warning

[ INFO: suspicious RCU usage. ]
-------------------------------
net/core/dev.c:2459 suspicious rcu_dereference_check() usage!

because we are locking with

rcu_read_lock_bh();

in function dev_queue_xmit(struct sk_buff *skb)
Signed-off-by: Igor Maravic <igorm@etf.rs>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of using a custom flow dissector, use skb_flow_dissect() and
benefit from tunnelling support.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of using a custom flow dissector, use skb_flow_dissect() and
benefit from tunnelling support.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tcp_sendmsg() uses select_size() helper to choose skb head size when a
new skb must be allocated.

If GSO is enabled for the socket, current strategy is to force all
payload data to be outside of headroom, in PAGE fragments.

This strategy is not welcome for small packets, wasting memory.

Experiments show that best results are obtained when using 2048 bytes
for skb head (This includes the skb overhead and various headers)

This patch provides better len/truesize ratios for packets sent to
loopback device, and reduce memory needs for in-flight loopback packets,
particularly on arches with big pages.

If a sender sends many 1-byte packets to an unresponsive application,
receiver rmem_alloc will grow faster and will stop queuing these packets
sooner, or will collapse its receive queue to free excess memory.

netperf -t TCP_RR results are improved by ~4 %, and many workloads are
improved as well (tbench, mysql...)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Le lundi 28 novembre 2011 à 19:06 -0500, David Miller a écrit :
> From: Dimitris Michailidis <dm@chelsio.com>
> Date: Mon, 28 Nov 2011 08:25:39 -0800
>
> >> +bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys
> >> *flow)
> >> +{
> >> +	int poff, nhoff = skb_network_offset(skb);
> >> +	u8 ip_proto;
> >> +	u16 proto = skb->protocol;
> >
> > __be16 instead of u16 for proto?
>
> I'll take care of this when I apply these patches.

( CC trimmed )

Thanks David !

Here is a small patch to use one 64bit load/store on x86_64 instead of
two 32bit load/stores.

[PATCH net-next] flow_dissector: use a 64bit load/store

gcc compiler is smart enough to use a single load/store if we
memcpy(dptr, sptr, 8) on x86_64, regardless of
CONFIG_CC_OPTIMIZE_FOR_SIZE

In IP header, daddr immediately follows saddr, this wont change in the
future. We only need to make sure our flow_keys (src,dst) fields wont
break the rule.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Changes to sfc to use byte queue limits.
Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Changes to bnx2x to use byte queue limits.
Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Changes to tg3 to use byte queue limits.
Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Changes to forcedeth to use byte queue limits.
Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Changes to e1000e to use byte queue limits.
Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Networking stack support for byte queue limits, uses dynamic queue
limits library.  Byte queue limits are maintained per transmit queue,
and a dql structure has been added to netdev_queue structure for this
purpose.

Configuration of bql is in the tx-<n> sysfs directory for the queue
under the byte_queue_limits directory.  Configuration includes:
limit_min, bql minimum limit
limit_max, bql maximum limit
hold_time, bql slack hold time

Also under the directory are:
limit, current byte limit
inflight, current number of bytes on the queue
Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch moves the xps specific parts in netdev_queue_release into
its own function which netdev_queue_release can call.  This allows
netdev_queue_release to be more generic (for adding new attributes
to tx queues).
Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add interfaces for drivers to call for recording number of packets and
bytes at send time and transmit completion.  Also, added a function to
"reset" a queue.  These will be used by Byte Queue Limits.
Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Create separate queue state flags so that either the stack or drivers
can turn on XOFF.  Added a set of functions used in the stack to determine
if a queue is really stopped (either by stack or driver)
Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Implementation of dynamic queue limits (dql).  This is a libary which
allows a queue limit to be dynamically managed.  The goal of dql is
to set the queue limit, number of objects to the queue, to be minimized
without allowing the queue to be starved.

dql would be used with a queue which has these properties:

1) Objects are queued up to some limit which can be expressed as a
   count of objects.
2) Periodically a completion process executes which retires consumed
   objects.
3) Starvation occurs when limit has been reached, all queued data has
   actually been consumed but completion processing has not yet run,
   so queuing new data is blocked.
4) Minimizing the amount of queued data is desirable.

A canonical example of such a queue would be a NIC HW transmit queue.

The queue limit is dynamic, it will increase or decrease over time
depending on the workload.  The queue limit is recalculated each time
completion processing is done.  Increases occur when the queue is
starved and can exponentially increase over successive intervals.
Decreases occur when more data is being maintained in the queue than
needed to prevent starvation.  The number of extra objects, or "slack",
is measured over successive intervals, and to avoid hysteresis the
limit is only reduced by the miminum slack seen over a configurable
time period.

dql API provides routines to manage the queue:
- dql_init is called to intialize the dql structure
- dql_reset is called to reset dynamic values
- dql_queued called when objects are being enqueued
- dql_avail returns availability in the queue
- dql_completed is called when objects have be consumed in the queue

Configuration consists of:
- max_limit, maximum limit
- min_limit, minimum limit
- slack_hold_time, time to measure instances of slack before reducing
  queue limit
Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add support for the XGMAC 10Gb ethernet device in the Calxeda Highbank
SOC.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Round-up some wayward "N/A" fw_version dust bunnies as part of that
clean-up.
Signed-off-by: Rick Jones <rick.jones2@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since 2005 (c1b4a7e6)
tcp_tso_should_defer has been using tcp_max_burst() as a target limit
for deciding how large to make outgoing TSO packets when not using
sysctl_tcp_tso_win_divisor. But since 2008
(dd9e0dda) tcp_max_burst() returns the
reordering degree. We should not have tcp_tso_should_defer attempt to
build larger segments just because there is more reordering. This
commit splits the notion of deferral size used in TSO from the notion
of burst size used in cwnd moderation, and returns the TSO deferral
limit to its original value.
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>