I received some bug reports about userspace programs having problems
because after RTM_NEWLINK was received they could not immediate access
files under /proc/sys/net/ because they had not been registered yet.
The original problem was trivially fixed by moving the userspace
notification from rtnetlink_event() to the end of
register_netdevice().
When testing that change I discovered I was still getting RTM_NEWLINK
events before I could access proc and I was also getting RTM_NEWLINK
events after I was seeing RTM_DELLINK. Things practically guaranteed
to confuse userspace.
After a little more investigation these extra notifications proved to
be from the new notifiers NETDEV_POST_INIT and NETDEV_UNREGISTER_BATCH
hitting the default case in rtnetlink_event, and triggering
unnecessary RTM_NEWLINK messages.
rtnetlink_event now explicitly handles NETDEV_UNREGISTER_BATCH and
NETDEV_POST_INIT to avoid sending the incorrect userspace
notifications.
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric W. Biedermanauthored and David S. Millercommited 2009-12-13 19:45:22 -08:00
Fix two problems:
1. If unregister_netdevice_many() is called with both registered
and unregistered devices, rollback_registered_many() bails out
when it reaches the first unregistered device. The processing
of the prior registered devices is unfinished, and the
remaining devices are skipped, and possible registered netdev's
are leaked/unregistered.
2. System hangs or panics depending on how the devices are passed,
since when netdev_run_todo() runs, some devices were not fully
processed.
Tested by passing intermingled unregistered and registered vlan
devices to unregister_netdevice_many() as follows:
1. dev, fake_dev1, fake_dev2: hangs in run_todo
("unregister_netdevice: waiting for eth1.100 to become
free. Usage count = 1")
2. fake_dev1, dev, fake_dev2: failure during de-registration
and next registration, followed by a vlan driver Oops
during subsequent registration.
Confirmed that the patch fixes both cases.
Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Krishna Kumarauthored and David S. Millercommited 2009-12-11 15:11:45 -08:00
Provide common routine for the transition of operational state for a leaf
device during a root device transition.
Signed-off-by: Patrick Mullaney <pmullaney@novell.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Patrick Mullaneyauthored and David S. Millercommited 2009-12-03 15:59:22 -08:00
Move network device exit batching from a special case in
net_namespace.c to using common mechanisms in dev.c
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric W. Biedermanauthored and David S. Millercommited 2009-12-03 12:22:02 -08:00
- Defer dellink to net_cleanup() allowing for batching.
- Fix comment.
- Use for_each_netdev_safe again as dev_change_net_namespace touches
at most one network device (unlike veth dellink).
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric W. Biedermanauthored and David S. Millercommited 2009-12-01 16:15:52 -08:00
The motivation for an additional notifier in batched netdevice
notification (rt_do_flush) only needs to be called once per batch not
once per namespace.
For further batching improvements I need a guarantee that the
netdevices are unregistered in order allowing me to unregister an all
of the network devices in a network namespace at the same time with
the guarantee that the loopback device is really and truly
unregistered last.
Additionally it appears that we moved the route cache flush after
the final synchronize_net, which seems wrong and there was no
explanation. So I have restored the original location of the final
synchronize_net.
Cc: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric W. Biedermanauthored and David S. Millercommited 2009-12-01 16:15:50 -08:00
Not including net/atm/
Compiled tested x86 allyesconfig only
Added a > 80 column line or two, which I ignored.
Existing checkpatch plaints willfully, cheerfully ignored.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Joe Perchesauthored and David S. Millercommited 2009-11-29 16:55:45 -08:00
The veth driver contains code to forward an skb
from the start_xmit function of one network
device into the receive path of another device.
Moving that code into a common location lets us
reuse the code for direct forwarding of data
between macvlan ports, and possibly in other
drivers.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Arnd Bergmannauthored and David S. Millercommited 2009-11-26 15:52:58 -08:00
Generated with the following semantic patch
@@
struct net *n1;
struct net *n2;
@@
- n1 == n2
+ net_eq(n1, n2)
@@
struct net *n1;
struct net *n2;
@@
- n1 != n2
+ !net_eq(n1, n2)
applied over {include,net,drivers/net}.
Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Octavian Purdilaauthored and David S. Millercommited 2009-11-25 15:14:13 -08:00
Fix the following htmldocs warning:
Warning(net/core/dev.c:5378): bad line:
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Jaswinder Singh Rajputauthored and David S. Millercommited 2009-11-22 20:43:13 -08:00
This new event is called once for each unique net namespace in batched
unregister operations (with the argument set to a random device from
that namespace) and once per device in non-batched unregister
operations.
It allows us to factorize some device unregister work such as clearing the
routing cache.
Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Octavian Purdilaauthored and David S. Millercommited 2009-11-18 05:03:03 -08:00
Some drivers ndo_get_stats() method need to perform txqueue stats folding.
Move folding from dev_get_stats() to a new dev_txq_stats_fold() function
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazetauthored and David S. Millercommited 2009-11-17 23:51:52 -08:00
net: Fix the rollback test in dev_change_name()
In dev_change_name() an err variable is used for storing the original
call_netdevice_notifiers() errno (negative) and testing for a rollback
error later, but the test for non-zero is wrong, because the err might
have positive value as well - from dev_alloc_name(). It means the
rollback for a netdevice with a number > 0 will never happen. (The err
test is reordered btw. to make it more readable.)
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazetauthored and David S. Millercommited 2009-11-16 03:30:35 -08:00
Recent changes in the TX error propagation require additional checking
and masking of values returned from hard_start_xmit(), mainly to
separate cases where skb was consumed. This aim can be simplified by
changing the order of NETDEV_TX and NET_XMIT codes, because the latter
are treated similarly to negative (ERRNO) values.
After this change much simpler dev_xmit_complete() is also used in
sch_direct_xmit(), so it is moved to netdevice.h.
Additionally NET_RX definitions in netdevice.h are moved up from
between TX codes to avoid confusion while reading the TX comment.
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Jarek Poplawskiauthored and David S. Millercommited 2009-11-15 22:08:33 -08:00
Check the return value of ndo_select_queue(). If the value isn't smaller
than the real_num_tx_queues, print a warning message, and reset it to zero.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
----
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazetauthored and David S. Millercommited 2009-11-15 22:08:05 -08:00
Currently the ->ndo_hard_start_xmit() callbacks are only permitted to return
one of the NETDEV_TX codes. This prevents any kind of error propagation for
virtual devices, like queue congestion of the underlying device in case of
layered devices, or unreachability in case of tunnels.
This patches changes the NET_XMIT codes to avoid clashes with the NETDEV_TX
codes and changes the two callers of dev_hard_start_xmit() to expect either
errno codes, NET_XMIT codes or NETDEV_TX codes as return value.
In case of qdisc_restart(), all non NETDEV_TX codes are mapped to NETDEV_TX_OK
since no error propagation is possible when using qdiscs. In case of
dev_queue_xmit(), the error is propagated upwards.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Patrick McHardyauthored and David S. Millercommited 2009-11-13 14:07:32 -08:00
The full_name_hash function does not produce well distributed values in
the lower bits, so most code uses hash_32() to fold it. This is really
a bug introduced when name hashing was added, back in 2.5 when I added
name hashing.
hash_32 is all that is needed since full_name_hash returns unsigned int
which is only 32 bits on 64 bit platforms.
Also, there is no point in using hash_32 on ifindex, because the is naturally
sequential and usually well distributed.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
stephen hemmingerauthored and David S. Millercommited 2009-11-11 19:22:12 -08:00
Adds RCU management to the list of netdevices.
Convert some for_each_netdev() users to RCU version, if
it can avoid read_lock-ing dev_base_lock
Ie:
read_lock(&dev_base_loack);
for_each_netdev(net, dev)
some_action();
read_unlock(&dev_base_lock);
becomes :
rcu_read_lock();
for_each_netdev_rcu(net, dev)
some_action();
rcu_read_unlock();
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazetauthored and David S. Millercommited 2009-11-04 05:43:23 -08:00
All ioctls() implemented by dev_ifsioc_locked() :
SIOCGIFFLAGS, SIOCGIFMETRIC, SIOCGIFMTU, SIOCGIFHWADDR,
SIOCGIFSLAVE, SIOCGIFMAP, SIOCGIFINDEX & SIOCGIFTXQLEN
can use RCU lock instead of dev_base_lock rwlock
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazetauthored and David S. Millercommited 2009-11-01 23:55:11 -08:00
I tested the recent unregister many changes and got a weird,
nasty and seemingly unrelasted kernel oops. Changing
unregister_netdevice_queue to use list_move_tail fixes
the problem for me.
ip link add type veth
rmmod veth
ls /sys/class/net/
showed one of the veth devices still present.
A subsequent ip link oopsed the box.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric W. Biedermanauthored and David S. Millercommited 2009-11-01 23:55:09 -08:00
Some workloads hit dev_base_lock rwlock pretty hard.
We can use RCU lookups to avoid touching this rwlock
(and avoid touching netdevice refcount)
netdevices are already freed after a RCU grace period, so this patch
adds no penalty at device dismantle time.
However, it adds a synchronize_rcu() call in dev_change_name()
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazetauthored and David S. Millercommited 2009-11-01 23:55:08 -08:00
Small cleanup of __dev_get_by_name() and __dev_get_by_index()
to use hlist_for_each_entry() : They'll look like their _rcu variant.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazetauthored and David S. Millercommited 2009-10-30 01:40:11 -07:00
This will allow drivers to adjust their receive path dynamically
based on whether GRO is being applied successfully.
Currently all in-tree callers ignore the return values of these
functions and do not need to be changed.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Ben Hutchingsauthored and David S. Millercommited 2009-10-29 21:36:53 -07:00
This clarifies which return and parameter types are GRO result codes
and not RX result codes.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Ben Hutchingsauthored and David S. Millercommited 2009-10-29 21:33:55 -07:00
Some workloads hit dev_base_lock rwlock pretty hard.
We can use RCU lookups to avoid touching this rwlock.
netdevices are already freed after a RCU grace period, so this patch
adds no penalty at device dismantle time.
dev_ifname() converted to dev_get_by_index_rcu()
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazetauthored and David S. Millercommited 2009-10-29 01:42:55 -07:00
Use unregister_netdevice_many() to speedup master device unregister.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazetauthored and David S. Millercommited 2009-10-28 02:22:08 -07:00
Adding a list_head parameter to rtnl_link_ops->dellink() methods
allow us to queue devices on a list, in order to dismantle
them all at once.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazetauthored and David S. Millercommited 2009-10-28 02:22:07 -07:00
Introduce rollback_registered_many() and unregister_netdevice_many()
rollback_registered_many() is able to perform necessary steps at device dismantle
time, factorizing two expensive synchronize_net() calls.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazetauthored and David S. Millercommited 2009-10-28 02:22:06 -07:00
This patchs adds an unreg_list anchor to struct net_device, and
introduces an unregister_netdevice_queue() function, able to queue
a net_device to a list instead of immediately unregister it.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazetauthored and David S. Millercommited 2009-10-28 02:22:06 -07:00
We currently use a 16 bit field (vlan_tci) to store VLAN ID/PRIO on a skb.
Null value is used as a special value, meaning vlan tagging not enabled.
This forbids use of null vlan ID.
As pointed by David, some drivers use the 3 high order bits (PRIO)
As VLAN ID is 12 bits, we can use the remaining bit (CFI) as a flag, and
allow null VLAN ID.
In case future code really wants to use VLAN_CFI_MASK, we'll have to use
a bit outside of vlan_tci.
#define VLAN_PRIO_MASK 0xe000 /* Priority Code Point */
#define VLAN_PRIO_SHIFT 13
#define VLAN_CFI_MASK 0x1000 /* Canonical Format Indicator */
#define VLAN_TAG_PRESENT VLAN_CFI_MASK
#define VLAN_VID_MASK 0x0fff /* VLAN Identifier */
Reported-by: Gertjan Hofman <gertjan_hofman@yahoo.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazetauthored and David S. Millercommited 2009-10-27 01:02:33 -07:00
When handling large number of netdevice, rtnl_dump_ifinfo()
is very slow because it has O(N^2) complexity.
Instead of scanning one single list, we can use the 256 sub lists
of the dev_index hash table.
This considerably speedups "ip link" operations
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazetauthored and David S. Millercommited 2009-10-24 06:13:17 -07:00
For connected sockets, the first run of dev_pick_tx saves the
calculated txq in sk_tx_queue_mapping. This is not saved if
either the device has a queue select or the socket is not
connected. Next iterations of dev_pick_tx uses the cached value
of sk_tx_queue_mapping.
Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Krishna Kumarauthored and David S. Millercommited 2009-10-20 18:55:47 -07:00
Now that software UFO is supported, UFO can be enabled on master
devices like bridge, bond even though the attached device doesn't
support this feature in hardware.
This allows UFO to be used between KVM host and guest even when a
physical interface attached to the bridge doesn't support UFO.
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Sridhar Samudralaauthored and David S. Millercommited 2009-10-07 22:00:23 -07:00
For various purposes including a wireless extensions
bugfix, we need to hook into the netdev creation before
before netdev_register_kobject(). This will also ease
doing the dev type assignment that Marcel was working
on for cfg80211 drivers w/o touching them all.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Johannes Bergauthored and David S. Millercommited 2009-10-05 00:43:34 -07:00
Since commit 9b22ea5609
( net: fix packet socket delivery in rx irq handler )
We lost rx timestamping of packets received on accelerated vlans.
Effect is that tcpdump on real dev can show strange timings, since it gets rx timestamps
too late (ie at skb dequeueing time, not at skb queueing time)
14:47:26.986871 IP 192.168.20.110 > 192.168.20.141: icmp 64: echo request seq 1
14:47:26.986786 IP 192.168.20.141 > 192.168.20.110: icmp 64: echo reply seq 1
14:47:27.986888 IP 192.168.20.110 > 192.168.20.141: icmp 64: echo request seq 2
14:47:27.986781 IP 192.168.20.141 > 192.168.20.110: icmp 64: echo reply seq 2
14:47:28.986896 IP 192.168.20.110 > 192.168.20.141: icmp 64: echo request seq 3
14:47:28.986780 IP 192.168.20.141 > 192.168.20.110: icmp 64: echo reply seq 3
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazetauthored and David S. Millercommited 2009-09-30 16:42:42 -07:00
This patch fixes commit e36b9d16c6. The approach
there is to call dev_close()/dev_open() whenever the device type is changed in
order to remap the device IP multicast addresses to HW multicast addresses.
This approach suffers from 2 drawbacks:
*. It assumes tha the device is UP when calling dev_close(), or otherwise
dev_close() has no affect. It is worth to mention that initscripts (Redhat)
and sysconfig (Suse) doesn't act the same in this matter.
*. dev_close() has other side affects, like deleting entries from the routing
table, which might be unnecessary.
The fix here is to directly remap the IP multicast addresses to HW multicast
addresses for a bonding device that changes its type, and nothing else.
Reported-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Moni Shoua <monis@voltaire.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Moni Shouaauthored and David S. Millercommited 2009-09-15 02:37:40 -07:00
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1623 commits)
netxen: update copyright
netxen: fix tx timeout recovery
netxen: fix file firmware leak
netxen: improve pci memory access
netxen: change firmware write size
tg3: Fix return ring size breakage
netxen: build fix for INET=n
cdc-phonet: autoconfigure Phonet address
Phonet: back-end for autoconfigured addresses
Phonet: fix netlink address dump error handling
ipv6: Add IFA_F_DADFAILED flag
net: Add DEVTYPE support for Ethernet based devices
mv643xx_eth.c: remove unused txq_set_wrr()
ucc_geth: Fix hangs after switching from full to half duplex
ucc_geth: Rearrange some code to avoid forward declarations
phy/marvell: Make non-aneg speed/duplex forcing work for 88E1111 PHYs
drivers/net/phy: introduce missing kfree
drivers/net/wan: introduce missing kfree
net: force bridge module(s) to be GPL
Subject: [PATCH] appletalk: Fix skb leak when ipddp interface is not loaded
...
Fixed up trivial conflicts:
- arch/x86/include/asm/socket.h
converted to <asm-generic/socket.h> in the x86 tree. The generic
header has the same new #define's, so that works out fine.
- drivers/net/tun.c
fix conflict between 89f56d1e9 ("tun: reuse struct sock fields") that
switched over to using 'tun->socket.sk' instead of the redundantly
available (and thus removed) 'tun->sk', and 2b980dbd ("lsm: Add hooks
to the TUN driver") which added a new 'tun->sk' use.
Noted in 'next' by Stephen Rothwell.
The only valid usage for the bridge frame hooks are by a
GPL components (such as the bridge module).
The kernel should not leave a crack in the door for proprietary
networking stacks to slip in.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stephen Hemmingerauthored and David S. Millercommited 2009-09-11 12:54:26 -07:00
Remove a debugging aid I accidently left in previous 'cleanup' patch
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazetauthored and David S. Millercommited 2009-09-03 05:17:20 -07:00
Patch compiled and 32 simultaneous netperf testing ran fine.
Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Krishna Kumarauthored and David S. Millercommited 2009-08-30 22:16:57 -07:00
There are not maste devices in mac802154 anymore, so drop
ARPHRD_IEEE802154_PHY definition.
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
The networking code checks CAP_SYS_MODULE before using request_module() to
try to load a kernel module. While this seems reasonable it's actually
weakening system security since we have to allow CAP_SYS_MODULE for things
like /sbin/ip and bluetoothd which need to be able to trigger module loads.
CAP_SYS_MODULE actually grants those binaries the ability to directly load
any code into the kernel. We should instead be protecting modprobe and the
modules on disk, rather than granting random programs the ability to load code
directly into the kernel. Instead we are going to gate those networking checks
on CAP_NET_ADMIN which still limits them to root but which does not grant
those processes the ability to load arbitrary code into the kernel.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Paul Moore <paul.moore@hp.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Morris <jmorris@namei.org>
Eric Parisauthored and James Morriscommited 2009-08-14 11:18:34 +10:00
dev_queue_xmit enqueue's a skb and calls qdisc_run which
dequeue's the skb and xmits it. In most cases, the skb that
is enqueue'd is the same one that is dequeue'd (unless the
queue gets stopped or multiple cpu's write to the same queue
and ends in a race with qdisc_run). For default qdiscs, we
can remove the redundant enqueue/dequeue and simply xmit the
skb since the default qdisc is work-conserving.
The patch uses a new flag - TCQ_F_CAN_BYPASS to identify the
default fast queue. The controversial part of the patch is
incrementing qlen when a skb is requeued - this is to avoid
checks like the second line below:
+ } else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
>> !q->gso_skb &&
+ !test_and_set_bit(__QDISC_STATE_RUNNING, &q->state)) {
Results of a 2 hour testing for multiple netperf sessions (1,
2, 4, 8, 12 sessions on a 4 cpu system-X). The BW numbers are
aggregate Mb/s across iterations tested with this version on
System-X boxes with Chelsio 10gbps cards:
----------------------------------
Size | ORG BW NEW BW |
----------------------------------
128K | 156964 159381 |
256K | 158650 162042 |
----------------------------------
Changes from ver1:
1. Move sch_direct_xmit declaration from sch_generic.h to
pkt_sched.h
2. Update qdisc basic statistics for direct xmit path.
3. Set qlen to zero in qdisc_reset.
4. Changed some function names to more meaningful ones.
Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Krishna Kumarauthored and David S. Millercommited 2009-08-06 20:10:18 -07:00
Eric W. Biederman
authored and
David S. Miller
commited 
Krishna Kumar
authored and
Patrick Mullaney
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Joe Perches
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Arnd Bergmann
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Octavian Purdila
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Jarek Poplawski
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stephen hemminger
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