Commit graph

422 commits

Author SHA1 Message Date
Vlad Dogaru
23b41168fc netdevice: make initial group visible to userspace
INIT_NETDEV_GROUP is needed by userspace, move it outside __KERNEL__
guards.

Signed-off-by: Vlad Dogaru <ddvlad@rosedu.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-02 21:55:52 -08:00
Michał Mirosław
e83d360d9a net: introduce NETIF_F_RXCSUM
Introduce NETIF_F_RXCSUM to replace device-private flags for RX checksum
offload. Integrate it with ndo_fix_features.

ethtool_op_get_rx_csum() is removed altogether as nothing in-tree uses it.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-17 14:16:35 -08:00
Michał Mirosław
5455c6998d net: Introduce new feature setting ops
This introduces a new framework to handle device features setting.
It consists of:
  - new fields in struct net_device:
	+ hw_features - features that hw/driver supports toggling
	+ wanted_features - features that user wants enabled, when possible
  - new netdev_ops:
	+ feat = ndo_fix_features(dev, feat) - API checking constraints for
		enabling features or their combinations
	+ ndo_set_features(dev) - API updating hardware state to match
		changed dev->features
  - new ethtool commands:
	+ ETHTOOL_GFEATURES/ETHTOOL_SFEATURES: get/set dev->wanted_features
		and trigger device reconfiguration if resulting dev->features
		changed
	+ ETHTOOL_GSTRINGS(ETH_SS_FEATURES): get feature bits names (meaning)

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-17 14:16:33 -08:00
Michał Mirosław
0a41770477 ethtool: factorize get/set_one_feature
This allows to enable GRO even if RX csum is disabled. GRO will not
be used for packets without hardware checksum anyway.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-17 14:16:33 -08:00
Michał Mirosław
212b573f55 ethtool: enable GSO and GRO by default
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-17 14:16:32 -08:00
Jiri Pirko
fbaec0ea54 rtnetlink: implement setting of master device
This patch allows userspace to enslave/release slave devices via netlink
interface using IFLA_MASTER. This introduces generic way to add/remove
underling devices.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-13 16:58:39 -08:00
Jiri Pirko
1765a57533 net: make dev->master general
dev->master is now tightly connected to bonding driver. This patch makes
this pointer more general and ready to be used by others.

 - netdev_set_master() - bond specifics moved to new function
   netdev_set_bond_master()
 - introduced netif_is_bond_slave() to check if device is a bonding slave

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-13 10:42:07 -08:00
Jiri Pirko
d59cfde2fb net: remove the unnecessary dance around skb_bond_should_drop
No need to check (master) twice and to drive in and out the header file.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Reviewed-by: Nicolas de Pesloüan <nicolas.2p.debian@free.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-13 10:42:06 -08:00
Eric Dumazet
ccf434380d net: fix dev_seq_next()
Commit c6d14c8456 (net: Introduce for_each_netdev_rcu() iterator)
added a race in dev_seq_next().

The rcu_dereference() call should be done _before_ testing the end of
list, or we might return a wrong net_device if a concurrent thread
changes net_device list under us.

Note : discovered thanks to a sparse warning :

net/core/dev.c:3919:9: error: incompatible types in comparison expression
(different address spaces)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-27 15:02:56 -08:00
Michał Mirosław
acd1130e87 net: reduce and unify printk level in netdev_fix_features()
Reduce printk() levels to KERN_INFO in netdev_fix_features() as this will
be used by ethtool and might spam dmesg unnecessarily.

This converts the function to use netdev_info() instead of plain printk().

As a side effect, bonding and bridge devices will now log dropped features
on every slave device change.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-24 15:45:15 -08:00
Michał Mirosław
04ed3e741d net: change netdev->features to u32
Quoting Ben Hutchings: we presumably won't be defining features that
can only be enabled on 64-bit architectures.

Occurences found by `grep -r` on net/, drivers/net, include/

[ Move features and vlan_features next to each other in
  struct netdev, as per Eric Dumazet's suggestion -DaveM ]

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-24 15:32:47 -08:00
Ben Hutchings
c445477d74 net: RPS: Enable hardware acceleration of RFS
Allow drivers for multiqueue hardware with flow filter tables to
accelerate RFS.  The driver must:

1. Set net_device::rx_cpu_rmap to a cpu_rmap of the RX completion
IRQs (in queue order).  This will provide a mapping from CPUs to the
queues for which completions are handled nearest to them.

2. Implement net_device_ops::ndo_rx_flow_steer.  This operation adds
or replaces a filter steering the given flow to the given RX queue, if
possible.

3. Periodically remove filters for which rps_may_expire_flow() returns
true.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-24 14:53:01 -08:00
John Fastabend
4f57c087de net: implement mechanism for HW based QOS
This patch provides a mechanism for lower layer devices to
steer traffic using skb->priority to tx queues. This allows
for hardware based QOS schemes to use the default qdisc without
incurring the penalties related to global state and the qdisc
lock. While reliably receiving skbs on the correct tx ring
to avoid head of line blocking resulting from shuffling in
the LLD. Finally, all the goodness from txq caching and xps/rps
can still be leveraged.

Many drivers and hardware exist with the ability to implement
QOS schemes in the hardware but currently these drivers tend
to rely on firmware to reroute specific traffic, a driver
specific select_queue or the queue_mapping action in the
qdisc.

By using select_queue for this drivers need to be updated for
each and every traffic type and we lose the goodness of much
of the upstream work. Firmware solutions are inherently
inflexible. And finally if admins are expected to build a
qdisc and filter rules to steer traffic this requires knowledge
of how the hardware is currently configured. The number of tx
queues and the queue offsets may change depending on resources.
Also this approach incurs all the overhead of a qdisc with filters.

With the mechanism in this patch users can set skb priority using
expected methods ie setsockopt() or the stack can set the priority
directly. Then the skb will be steered to the correct tx queues
aligned with hardware QOS traffic classes. In the normal case with
single traffic class and all queues in this class everything
works as is until the LLD enables multiple tcs.

To steer the skb we mask out the lower 4 bits of the priority
and allow the hardware to configure upto 15 distinct classes
of traffic. This is expected to be sufficient for most applications
at any rate it is more then the 8021Q spec designates and is
equal to the number of prio bands currently implemented in
the default qdisc.

This in conjunction with a userspace application such as
lldpad can be used to implement 8021Q transmission selection
algorithms one of these algorithms being the extended transmission
selection algorithm currently being used for DCB.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-19 23:31:10 -08:00
Vlad Dogaru
cbda10fa97 net_device: add support for network device groups
Net devices can now be grouped, enabling simpler manipulation from
userspace. This patch adds a group field to the net_device structure, as
well as rtnetlink support to query and modify it.

Signed-off-by: Vlad Dogaru <ddvlad@rosedu.org>
Acked-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-19 23:31:09 -08:00
Eric Dumazet
1ac9ad1394 net: remove dev_txq_stats_fold()
After recent changes, (percpu stats on vlan/tunnels...), we dont need
anymore per struct netdev_queue tx_bytes/tx_packets/tx_dropped counters.

Only remaining users are ixgbe, sch_teql, gianfar & macvlan :

1) ixgbe can be converted to use existing tx_ring counters.

2) macvlan incremented txq->tx_dropped, it can use the
dev->stats.tx_dropped counter.

3) sch_teql : almost revert ab35cd4b8f (Use net_device internal stats)
    Now we have ndo_get_stats64(), use it, even for "unsigned long"
fields (No need to bring back a struct net_device_stats)

4) gianfar adds a stats structure per tx queue to hold
tx_bytes/tx_packets

This removes a lockdep warning (and possible lockup) in rndis gadget,
calling dev_get_stats() from hard IRQ context.

Ref: http://www.spinics.net/lists/netdev/msg149202.html

Reported-by: Neil Jones <neiljay@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Jarek Poplawski <jarkao2@gmail.com>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
CC: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
CC: Sandeep Gopalpet <sandeep.kumar@freescale.com>
CC: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-13 21:44:34 -08:00
Tom Herbert
36909ea438 net: Add alloc_netdev_mqs function
Added alloc_netdev_mqs function which allows the number of transmit and
receive queues to be specified independenty.  alloc_netdev_mq was
changed to a macro to call the new function.  Also added
alloc_etherdev_mqs with same purpose.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-10 16:05:30 -08:00
Jesse Gross
fc741216db net offloading: Pass features into netif_needs_gso().
Now that there is a single function that can compute the device
features relevant to a packet, we don't want to run it for each
offload.  This converts netif_needs_gso() to take the features
of the device, rather than computing them itself.

Signed-off-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-09 23:35:34 -08:00
Jesse Gross
f01a5236bd net offloading: Generalize netif_get_vlan_features().
netif_get_vlan_features() is currently only used by netif_needs_gso(),
so it only concerns itself with GSO features.  However, several other
places also should take into account the contents of the packet when
deciding whether to offload to hardware.  This generalizes the function
to return features about all of the various forms of offloading.  Since
offloads tend to be linked together, this avoids duplicating the logic
in each location (i.e. the scatter/gather code also needs the checksum
logic).

Suggested-by: Michał Mirosław <mirqus@gmail.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-09 23:35:33 -08:00
Michal Simek
68763c890e trivial: Fix typo fault in netdevice.h
Signed-off-by: Michal Simek <monstr@monstr.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-03 12:06:21 -08:00
Changli Gao
b236da6931 net: use NUMA_NO_NODE instead of the magic number -1
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-16 13:16:06 -08:00
Vladislav Zolotarov
a3d22a68d7 bnx2x: Take the distribution range definition out of skb_tx_hash()
Move the calcualation of the Tx hash for a given hash range into a separate
function and define the skb_tx_hash(), which calculates a Tx hash for a
[0; dev->real_num_tx_queues - 1] hash values range, using this
function (__skb_tx_hash()).

Signed-off-by: Vladislav Zolotarov <vladz@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-16 13:15:53 -08:00
Eric Dumazet
941666c2e3 net: RCU conversion of dev_getbyhwaddr() and arp_ioctl()
Le dimanche 05 décembre 2010 à 09:19 +0100, Eric Dumazet a écrit :

> Hmm..
>
> If somebody can explain why RTNL is held in arp_ioctl() (and therefore
> in arp_req_delete()), we might first remove RTNL use in arp_ioctl() so
> that your patch can be applied.
>
> Right now it is not good, because RTNL wont be necessarly held when you
> are going to call arp_invalidate() ?

While doing this analysis, I found a refcount bug in llc, I'll send a
patch for net-2.6

Meanwhile, here is the patch for net-next-2.6

Your patch then can be applied after mine.

Thanks

[PATCH] net: RCU conversion of dev_getbyhwaddr() and arp_ioctl()

dev_getbyhwaddr() was called under RTNL.

Rename it to dev_getbyhwaddr_rcu() and change all its caller to now use
RCU locking instead of RTNL.

Change arp_ioctl() to use RCU instead of RTNL locking.

Note: this fix a dev refcount bug in llc

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08 10:07:24 -08:00
Eric Dumazet
f2cd2d3e9b net sched: use xps information for qdisc NUMA affinity
Allocate qdisc memory according to NUMA properties of cpus included in
xps map.

To be effective, qdisc should be (re)setup after changes
of /sys/class/net/eth<n>/queues/tx-<n>/xps_cpus

I added a numa_node field in struct netdev_queue, containing NUMA node
if all cpus included in xps_cpus share same node, else -1.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-01 12:47:42 -08:00
Eric Dumazet
a417786948 xps: add __rcu annotations
Avoid sparse warnings : add __rcu annotations and use
rcu_dereference_protected() where necessary.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-29 09:43:13 -08:00
Tom Herbert
bf26414510 xps: Add CONFIG_XPS
This patch adds XPS_CONFIG option to enable and disable XPS.  This is
done in the same manner as RPS_CONFIG.  This is also fixes build
failure in XPS code when SMP is not enabled.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-28 18:24:14 -08:00
Eric Dumazet
5a0d2268d2 net: add netif_tx_queue_frozen_or_stopped
When testing struct netdev_queue state against FROZEN bit, we also test
XOFF bit. We can test both bits at once and save some cycles.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-28 10:47:18 -08:00
Tom Herbert
1d24eb4815 xps: Transmit Packet Steering
This patch implements transmit packet steering (XPS) for multiqueue
devices.  XPS selects a transmit queue during packet transmission based
on configuration.  This is done by mapping the CPU transmitting the
packet to a queue.  This is the transmit side analogue to RPS-- where
RPS is selecting a CPU based on receive queue, XPS selects a queue
based on the CPU (previously there was an XPS patch from Eric
Dumazet, but that might more appropriately be called transmit completion
steering).

Each transmit queue can be associated with a number of CPUs which will
use the queue to send packets.  This is configured as a CPU mask on a
per queue basis in:

/sys/class/net/eth<n>/queues/tx-<n>/xps_cpus

The mappings are stored per device in an inverted data structure that
maps CPUs to queues.  In the netdevice structure this is an array of
num_possible_cpu structures where each structure holds and array of
queue_indexes for queues which that CPU can use.

The benefits of XPS are improved locality in the per queue data
structures.  Also, transmit completions are more likely to be done
nearer to the sending thread, so this should promote locality back
to the socket on free (e.g. UDP).  The benefits of XPS are dependent on
cache hierarchy, application load, and other factors.  XPS would
nominally be configured so that a queue would only be shared by CPUs
which are sharing a cache, the degenerative configuration woud be that
each CPU has it's own queue.

Below are some benchmark results which show the potential benfit of
this patch.  The netperf test has 500 instances of netperf TCP_RR test
with 1 byte req. and resp.

bnx2x on 16 core AMD
   XPS (16 queues, 1 TX queue per CPU)  1234K at 100% CPU
   No XPS (16 queues)                   996K at 100% CPU

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-24 11:44:20 -08:00
stephen hemminger
61391cde9e netdev: add rcu annotations to receive handler hook
Suggested by Eric's bridge RCU changes.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-15 11:13:17 -08:00
Tom Herbert
fe8222406c net: Simplify RX queue allocation
This patch move RX queue allocation to alloc_netdev_mq and freeing of
the queues to free_netdev (symmetric to TX queue allocation).  Each
kobject RX queue takes a reference to the queue's device so that the
device can't be freed before all the kobjects have been released-- this
obviates the need for reference counts specific to RX queues.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-15 10:57:28 -08:00
Jesse Gross
58e998c6d2 offloading: Force software GSO for multiple vlan tags.
We currently use vlan_features to check for TSO support if there is
a vlan tag.  However, it's quite likely that the NIC is not able to
do TSO when there is an arbitrary number of tags.  Therefore if there
is more than one tag (in-band or out-of-band), fall back to software
emulation.

Signed-off-by: Jesse Gross <jesse@nicira.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-15 09:22:53 -08:00
Eric Dumazet
fc766e4c49 decnet: RCU conversion and get rid of dev_base_lock
While tracking dev_base_lock users, I found decnet used it in
dnet_select_source(), but for a wrong purpose:

Writers only hold RTNL, not dev_base_lock, so readers must use RCU if
they cannot use RTNL.

Adds an rcu_head in struct dn_ifaddr and handle proper RCU management.

Adds __rcu annotation in dn_route as well.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-08 13:50:08 -08:00
Guillaume Chazarain
18543a643f net: Detect and ignore netif_stop_queue() calls before register_netdev()
After e6484930d7: net: allocate tx queues in register_netdevice
These calls make net drivers oops at load time, so let's avoid people
git-bisect'ing known problems.

Signed-off-by: Guillaume Chazarain <guichaz@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-08 12:17:07 -08:00
Eric Dumazet
6e3f7faf3e rps: add __rcu annotations
Add __rcu annotations to :
	(struct netdev_rx_queue)->rps_map
	(struct netdev_rx_queue)->rps_flow_table
	struct rps_sock_flow_table *rps_sock_flow_table;

And use appropriate rcu primitives.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-25 14:18:27 -07:00
Eric Dumazet
3cc77ec74e net/802: add __rcu annotations
(struct net_device)->garp_port is rcu protected :
(struct garp_port)->applicants is rcu protected :

add __rcu annotation and proper rcu primitives.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-25 13:09:44 -07:00
Eric Dumazet
198caeca3e ipv6: ip6_ptr rcu annotations
(struct net_device)->ip6_ptr is rcu protected :

add __rcu annotation and proper rcu primitives.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-25 13:09:43 -07:00
Eric Dumazet
b616b09afa vlan: rcu annotations
(struct net_device)->vlgrp is rcu protected :

add __rcu annotation and proper rcu primitives.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-25 13:09:43 -07:00
stephen hemminger
d0c2b0d265 napi: unexport napi_reuse_skb
The function napi_reuse_skb is only used inside core.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21 04:26:38 -07:00
Jesse Gross
3701e51382 vlan: Centralize handling of hardware acceleration.
Currently each driver that is capable of vlan hardware acceleration
must be aware of the vlan groups that are configured and then pass
the stripped tag to a specialized receive function.  This is

different from other types of hardware offload in that it places a
significant amount of knowledge in the driver itself rather keeping
it in the networking core.

This makes vlan offloading function more similarly to other forms
of offloading (such as checksum offloading or TSO) by doing the
following:
* On receive, stripped vlans are passed directly to the network
core, without attempting to check for vlan groups or reconstructing
the header if no group
* vlans are made less special by folding the logic into the main
receive routines
* On transmit, the device layer will add the vlan header in software
if the hardware doesn't support it, instead of spreading that logic
out in upper layers, such as bonding.

There are a number of advantages to this:
* Fixes all bugs with drivers incorrectly dropping vlan headers at once.
* Avoids having to disable VLAN acceleration when in promiscuous mode
(good for bridging since it always puts devices in promiscuous mode).
* Keeps VLAN tag separate until given to ultimate consumer, which
avoids needing to do header reconstruction as in tg3 unless absolutely
necessary.
* Consolidates common code in core networking.

Signed-off-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21 01:26:53 -07:00
Jesse Gross
65ac6a5fa6 vlan: Avoid hash table lookup to find group.
A struct net_device always maps to zero or one vlan groups and we
always know the device when we are looking up a group.  We currently
do a hash table lookup on the device to find the group but it is
much simpler to just store a pointer.

Signed-off-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21 01:26:53 -07:00
Jesse Gross
7b9c609037 vlan: Enable software emulation for vlan accleration.
Currently users of hardware vlan accleration need to know whether
the device supports it before generating packets.  However, vlan
acceleration will soon be available in a more flexible manner so
knowing ahead of time becomes much more difficult.  This adds
a software fallback path for vlan packets on devices without the
necessary offloading support, similar to other types of hardware
accleration.

Signed-off-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21 01:26:52 -07:00
Tom Herbert
e6484930d7 net: allocate tx queues in register_netdevice
This patch introduces netif_alloc_netdev_queues which is called from
register_device instead of alloc_netdev_mq.  This makes TX queue
allocation symmetric with RX allocation.  Also, queue locks allocation
is done in netdev_init_one_queue.  Change set_real_num_tx_queues to
fail if requested number < 1 or greater than number of allocated
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>
2010-10-20 02:27:59 -07:00
Eric Dumazet
29b4433d99 net: percpu net_device refcount
We tried very hard to remove all possible dev_hold()/dev_put() pairs in
network stack, using RCU conversions.

There is still an unavoidable device refcount change for every dst we
create/destroy, and this can slow down some workloads (routers or some
app servers, mmap af_packet)

We can switch to a percpu refcount implementation, now dynamic per_cpu
infrastructure is mature. On a 64 cpus machine, this consumes 256 bytes
per device.

On x86, dev_hold(dev) code :

before
        lock    incl 0x280(%ebx)
after:
        movl    0x260(%ebx),%eax
        incl    fs:(%eax)

Stress bench :

(Sending 160.000.000 UDP frames,
IP route cache disabled, dual E5540 @2.53GHz,
32bit kernel, FIB_TRIE)

Before:

real    1m1.662s
user    0m14.373s
sys     12m55.960s

After:

real    0m51.179s
user    0m15.329s
sys     10m15.942s

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-12 12:35:25 -07:00
Eric Dumazet
34d101dd62 neigh: speedup neigh_hh_init()
When a new dst is used to send a frame, neigh_resolve_output() tries to
associate an struct hh_cache to this dst, calling neigh_hh_init() with
the neigh rwlock write locked.

Most of the time, hh_cache is already known and linked into neighbour,
so we find it and increment its refcount.

This patch changes the logic so that we call neigh_hh_init() with
neighbour lock read locked only, so that fast path can be run in
parallel by concurrent cpus.

This brings part of the speedup we got with commit c7d4426a98
(introduce DST_NOCACHE flag) for non cached dsts, even for cached ones,
removing one of the contention point that routers hit on multiqueue
enabled machines.

Further improvements would need to use a seqlock instead of an rwlock to
protect neigh->ha[], to not dirty neigh too often and remove two atomic
ops.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-11 09:16:57 -07:00
Eric Dumazet
caf586e5f2 net: add a core netdev->rx_dropped counter
In various situations, a device provides a packet to our stack and we
drop it before it enters protocol stack :
- softnet backlog full (accounted in /proc/net/softnet_stat)
- bad vlan tag (not accounted)
- unknown/unregistered protocol (not accounted)

We can handle a per-device counter of such dropped frames at core level,
and automatically adds it to the device provided stats (rx_dropped), so
that standard tools can be used (ifconfig, ip link, cat /proc/net/dev)

This is a generalization of commit 8990f468a (net: rx_dropped
accounting), thus reverting it.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-05 14:47:55 -07:00
Eric Dumazet
24824a09e3 net: dynamic ingress_queue allocation
ingress being not used very much, and net_device->ingress_queue being
quite a big object (128 or 256 bytes), use a dynamic allocation if
needed (tc qdisc add dev eth0 ingress ...)

dev_ingress_queue(dev) helper should be used only with RTNL taken.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-05 00:23:44 -07:00
Eric Dumazet
bfa5ae63b8 net: rename netdev rx_queue to ingress_queue
There is some confusion with rx_queue name after RPS, and net drivers
private rx_queue fields.

I suggest to rename "struct net_device"->rx_queue to ingress_queue.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-29 13:25:53 -07:00
Eric Dumazet
6d81f41c58 dummy: percpu stats and lockless xmit
Converts dummy network device driver to :

- percpu stats

- 64bit stats

- lockless xmit (NETIF_F_LLTX)

- performance features added (NETIF_F_SG | NETIF_F_FRAGLIST |
NETIF_F_TSO | NETIF_F_NO_CSUM | NETIF_F_HIGHDMA)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-29 13:23:30 -07:00
Ben Hutchings
3171d02629 net: Add netif_copy_real_num_queues() for use by virtual net drivers
This sets the active numbers of queues on a net device to match another.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-27 22:09:50 -07:00
Ben Hutchings
62fe0b40ab net: Allow changing number of RX queues after device allocation
For RPS, we create a kobject for each RX queue based on the number of
queues passed to alloc_netdev_mq().  However, drivers generally do not
determine the numbers of hardware queues to use until much later, so
this usually represents the maximum number the driver may use and not
the actual number in use.

For TX queues, drivers can update the actual number using
netif_set_real_num_tx_queues().  Add a corresponding function for RX
queues, netif_set_real_num_rx_queues().

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-27 22:09:49 -07:00
Eric Dumazet
290b895e0b tunnels: prepare percpu accounting
Tunnels are going to use percpu for their accounting.

They are going to use a new tstats field in net_device.

skb_tunnel_rx() is changed to be a wrapper around __skb_tunnel_rx()

IPTUNNEL_XMIT() is changed to be a wrapper around __IPTUNNEL_XMIT()

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-27 21:30:42 -07:00