linux-stable.git/drivers/net/tun.c, branch v3.1

net: Audit drivers to identify those needing IFF_TX_SKB_SHARING cleared

2011-07-28T05:39:30+00:00

After the last patch, We are left in a state in which only drivers calling
ether_setup have IFF_TX_SKB_SHARING set (we assume that drivers touching real
hardware call ether_setup for their net_devices and don't hold any state in
their skbs.  There are a handful of drivers that violate this assumption of
course, and need to be fixed up.  This patch identifies those drivers, and marks
them as not being able to support the safe transmission of skbs by clearning the
IFF_TX_SKB_SHARING flag in priv_flags

Signed-off-by: Neil Horman 
CC: Karsten Keil 
CC: "David S. Miller" 
CC: Jay Vosburgh 
CC: Andy Gospodarek 
CC: Patrick McHardy 
CC: Krzysztof Halasa 
CC: "John W. Linville" 
CC: Greg Kroah-Hartman 
CC: Marcel Holtmann 
CC: Johannes Berg 
Signed-off-by: David S. Miller

Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6

2011-06-21T05:29:08+00:00

Conflicts:
	drivers/net/wireless/iwlwifi/iwl-agn-rxon.c
	drivers/net/wireless/rtlwifi/pci.c
	net/netfilter/ipvs/ip_vs_core.c

tun: teach the tun/tap driver to support netpoll

2011-06-17T03:53:10+00:00

Commit 8d8fc29d02a33e4bd5f4fa47823c1fd386346093 changed the behavior of slave
devices in regards to netpoll.  Specifically it created a mutually exclusive
relationship between being a slave and a netpoll-capable device.  This creates
problems for KVM because guests relied on needing netconsole active on a slave
device to a bridge.  Ideally libvirtd could just attach netconsole to the bridge
device instead, but thats currently infeasible, because while the bridge device
supports netpoll, it requires that all slave interface also support it, but the
tun/tap driver currently does not.  The most direct solution is to teach tun/tap
to support netpoll, which is implemented by the patch below.

I've not tested this yet, but its pretty straightforward.

Signed-off-by: Neil Horman 
Reported-by: Rik van Riel 
CC: Rik van Riel 
CC: Maxim Krasnyansky 
CC: Cong Wang 
CC: "David S. Miller" 
Reviewed-by: Rik van Riel 
Tested-by: Rik van Riel 
Reviewed-by: WANG Cong 
Signed-off-by: David S. Miller

virtio_net: introduce VIRTIO_NET_HDR_F_DATA_VALID

2011-06-11T22:57:47+00:00

There's no need for the guest to validate the checksum if it have been
validated by host nics. So this patch introduces a new flag -
VIRTIO_NET_HDR_F_DATA_VALID which is used to bypass the checksum
examing in guest. The backend (tap/macvtap) may set this flag when
met skbs with CHECKSUM_UNNECESSARY to save cpu utilization.

No feature negotiation is needed as old driver just ignore this flag.

Iperf shows 12%-30% performance improvement for UDP traffic. For TCP,
when gro is on no difference as it produces skb with partial
checksum. But when gro is disabled, 20% or even higher improvement
could be measured by netperf.

Signed-off-by: Jason Wang 
Acked-by: Michael S. Tsirkin 
Signed-off-by: David S. Miller

tun: do not put self in waitq if doing a nonblock read

2011-06-09T07:27:10+00:00

Perf shows a relatively high rate (about 8%) race in
spin_lock_irqsave() when doing netperf between external host and
guest. It's mainly becuase the lock contention between the
tun_do_read() and tun_xmit_skb(), so this patch do not put self into
waitqueue to reduce this kind of race. After this patch, it drops to
4%.

Signed-off-by: Jason Wang 
Signed-off-by: Amos Kong 
Signed-off-by: David S. Miller

tun: dont force inline of functions

2011-06-09T07:08:39+00:00

Current standard practice is to not mark most functions as inline
and  let compiler decide instead.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

tun: reserves space for network in skb

2011-06-09T07:08:38+00:00

The tun driver allocates skb's to hold data from user and then passes
the data into the network stack as received data. Most network devices
allocate the receive skb with routines like dev_alloc_skb() that reserves
additional space for use by network protocol stack but tun does not.

Because of the lack of padding, when the packet is passed through bridge
netfilter a new skb has to be allocated.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

drivers/net: Remove unnecessary semicolons

2011-06-05T21:33:40+00:00

Semicolons are not necessary after switch/while/for/if braces
so remove them.

Signed-off-by: Joe Perches 
Signed-off-by: David S. Miller

net: call dev_alloc_name from register_netdevice

2011-05-05T17:57:45+00:00

Force dev_alloc_name() to be called from register_netdevice() by
dev_get_valid_name(). That allows to remove multiple explicit
dev_alloc_name() calls.

The possibility to call dev_alloc_name in advance remains.

This also fixes veth creation regresion caused by
84c49d8c3e4abefb0a41a77b25aa37ebe8d6b743

Signed-off-by: Jiri Pirko 
Signed-off-by: David S. Miller

ethtool: cosmetic: Use ethtool ethtool_cmd_speed API

2011-04-29T21:03:01+00:00

This updates the network drivers so that they don't access the
ethtool_cmd::speed field directly, but use ethtool_cmd_speed()
instead.

For most of the drivers, these changes are purely cosmetic and don't
fix any problem, such as for those 1GbE/10GbE drivers that indirectly
call their own ethtool get_settings()/mii_ethtool_gset(). The changes
are meant to enforce code consistency and provide robustness with
future larger throughputs, at the expense of a few CPU cycles for each
ethtool operation.

All drivers compiled with make allyesconfig ion x86_64 have been
updated.

Tested: make allyesconfig on x86_64 + e1000e/bnx2x work
Signed-off-by: David Decotigny 
Signed-off-by: David S. Miller