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path: root/drivers/net/loopback.c
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2009-05-18net: release dst entry in dev_hard_start_xmit()Eric Dumazet
One point of contention in high network loads is the dst_release() performed when a transmited skb is freed. This is because NIC tx completion calls dev_kree_skb() long after original call to dev_queue_xmit(skb). CPU cache is cold and the atomic op in dst_release() stalls. On SMP, this is quite visible if one CPU is 100% handling softirqs for a network device, since dst_clone() is done by other cpus, involving cache line ping pongs. It seems right place to release dst is in dev_hard_start_xmit(), for most devices but ones that are virtual, and some exceptions. David Miller suggested to define a new device flag, set in alloc_netdev_mq() (so that most devices set it at init time), and carefuly unset in devices which dont want a NULL skb->dst in their ndo_start_xmit(). List of devices that must clear this flag is : - loopback device, because it calls netif_rx() and quoting Patrick : "ip_route_input() doesn't accept loopback addresses, so loopback packets already need to have a dst_entry attached." - appletalk/ipddp.c : needs skb->dst in its xmit function - And all devices that call again dev_queue_xmit() from their xmit function (as some classifiers need skb->dst) : bonding, vlan, macvlan, eql, ifb, hdlc_fr Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-20loopback: packet drops accountingEric Dumazet
We can in some situations drop packets in netif_rx() loopback driver does not report these (unlikely) drops to its stats, and incorrectly change packets/bytes counts. After this patch applied, "ifconfig lo" can reports these drops as in : # ifconfig lo lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:692562900 errors:3228 dropped:3228 overruns:0 frame:0 TX packets:692562900 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:2865674174 (2.6 GiB) TX bytes:2865674174 (2.6 GiB) I initialy chose to reflect those errors only in tx_dropped/tx_errors, but David convinced me that it was really RX errors, as loopback_xmit() really starts a RX process. (calling eth_type_trans() for example, that itself pulls the ethernet header) These errors are accounted in rx_dropped/rx_errors. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-20netdev: add more functions to netdevice opsStephen Hemminger
This patch moves neigh_setup and hard_start_xmit into the network device ops structure. For bisection, fix all the previously converted drivers as well. Bonding driver took the biggest hit on this. Added a prefetch of the hard_start_xmit in the fast path to try and reduce any impact this would have. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-19netdev: convert loopback to net_device_opsStephen Hemminger
First device to convert over is the loopback device. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-07net: Guaranetee the proper ordering of the loopback device. v2Eric W. Biederman
I was recently hunting a bug that occurred in network namespace cleanup. In looking at the code it became apparrent that we have and will continue to have cases where if we have anything going on in a network namespace there will be assumptions that the loopback device is present. Things like sending igmp unsubscribe messages when we bring down network devices invokes the routing code which assumes that at least the loopback driver is present. Therefore to avoid magic initcall ordering hackery that is hard to follow and hard to get right insert a call to register the loopback device directly from net_dev_init(). This guarantes that the loopback device is the first device registered and the last network device to go away. But do it carefully so we register the loopback device after we clear dev_boot_phase. Signed-off-by: Eric W. Biederman <ebiederm@maxwell.aristanetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-07Revert "net: Guaranetee the proper ordering of the loopback device."David S. Miller
This reverts commit ae33bc40c0d96d02f51a996482ea7e41c5152695.
2008-11-05net: Guaranetee the proper ordering of the loopback device.Eric W. Biederman
I was recently hunting a bug that occurred in network namespace cleanup. In looking at the code it became apparrent that we have and will continue to have cases where if we have anything going on in a network namespace there will be assumptions that the loopback device is present. Things like sending igmp unsubscribe messages when we bring down network devices invokes the routing code which assumes that at least the loopback driver is present. Therefore to avoid magic initcall ordering hackery that is hard to follow and hard to get right insert a call to register the loopback device directly from net_dev_init(). This guarantes that the loopback device is the first device registered and the last network device to go away. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-03drivers/net: Kill now superfluous ->last_rx stores.David S. Miller
The generic packet receive code takes care of setting netdev->last_rx when necessary, for the sake of the bonding ARP monitor. Drivers need not do it any more. Some cases had to be skipped over because the drivers were making use of the ->last_rx value themselves. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-31net: Really remove all of LOOPBACK_TSO code.David S. Miller
As noticed by Saikiran Madugula, commit 7447ef63cf2dfdc444f4c72ae13f604350b2e25f ("loopback: Remove rest of LOOPBACK_TSO code.") got rid of emulate_large_send_offload() but didn't get rid of the call site as well. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-15loopback: Drop obsolete ip_summed settingHerbert Xu
Now that the network stack can handle inbound packets with partial checksums, we should no longer clobber the ip_summed field in the loopback driver. This is because CHECKSUM_UNNECESSARY implies that the checksum field is actually valid which is not true for loopback packets since it's only partial (and thus complemented). This allows packets from lo to then be SNATed to an external source while still preserving the checksum's validity. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-15loopback: Remove rest of LOOPBACK_TSO code.David S. Miller
It hasn't been enabled for a long time and the generic GSO engine is better documentation of what is expected of a device implementing TSO. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-15loopback: Enable TSOHerbert Xu
This patch enables TSO since the loopback device is naturally capable of handling packets of any size. This also means that we won't enable GSO on lo which is good until GSO is fixed to preserve netfilter state as netfilter treats loopback packets in a special way. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-17netdev: netdev_priv() can now be sane again.David S. Miller
The private area of a netdev is now at a fixed offset once more. Unfortunately, some assumptions that netdev_priv() == netdev->priv crept back into the tree. In particular this happened in the loopback driver. Make it use netdev->ml_priv. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-26[NET] NETNS: Omit net_device->nd_net without CONFIG_NET_NS.YOSHIFUJI Hideaki
Introduce per-net_device inlines: dev_net(), dev_net_set(). Without CONFIG_NET_NS, no namespace other than &init_net exists. Let's explicitly define them to help compiler optimizations. Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
2008-01-28[NET]: Remove unused define from loopback driver.Pavel Emelyanov
The LOOPBACK_OVERHEAD is not used in this file at all. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-12Fixed a small typo in the loopback driverEmil Medve
This is probably a result of the changes from commit 854d836 - [NET]: Dynamically allocate the loopback device, part 2 Signed-off-by: Emil Medve <Emilian.Medve@Freescale.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-11-13[NET]: Move unneeded data to initdata section.Denis V. Lunev
This patch reverts Eric's commit 2b008b0a8e96b726c603c5e1a5a7a509b5f61e35 It diets .text & .data section of the kernel if CONFIG_NET_NS is not set. This is safe after list operations cleanup. Signed-of-by: Denis V. Lunev <den@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-26[NET]: Marking struct pernet_operations __net_initdata was inappropriateEric W. Biederman
It is not safe to to place struct pernet_operations in a special section. We need struct pernet_operations to last until we call unregister_pernet_subsys. Which doesn't happen until module unload. So marking struct pernet_operations is a disaster for modules in two ways. - We discard it before we call the exit method it points to. - Because I keep struct pernet_operations on a linked list discarding it for compiled in code removes elements in the middle of a linked list and does horrible things for linked insert. So this looks safe assuming __exit_refok is not discarded for modules. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-15[NETNS]: Don't panic on creating the namespace's loopbackPavel Emelyanov
When the loopback device is failed to initialize inside the new namespaces, panic() is called. Do not do it when the namespace in question is not the init_net. Plus cleanup the error path a bit. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[NETNS]: Move some code into __init section when CONFIG_NET_NS=nPavel Emelyanov
With the net namespaces many code leaved the __init section, thus making the kernel occupy more memory than it did before. Since we have a config option that prohibits the namespace creation, the functions that initialize/finalize some netns stuff are simply not needed and can be freed after the boot. Currently, this is almost not noticeable, since few calls are no longer in __init, but when the namespaces will be merged it will be possible to free more code. I propose to use the __net_init, __net_exit and __net_initdata "attributes" for functions/variables that are not used if the CONFIG_NET_NS is not set to save more space in memory. The exiting functions cannot just reside in the __exit section, as noticed by David, since the init section will have references on it and the compilation will fail due to modpost checks. These references can exist, since the init namespace never dies and the exit callbacks are never called. So I introduce the __exit_refok attribute just like it is already done with the __init_refok. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[NET]: Bring comments in loopback.c uptodate.Eric W. Biederman
A hint as to why it is safe to use per cpu variables, and note that we actually can have multiple instances of the loopback device now. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[NET]: Proper comment for loopback initialization order.Denis V. Lunev
Loopback device is special. It should be initialized at the very beginning. Initialization order has been changed by Eric W. Biederman <ebiederm@xmission.com> and this change is non-obvious and important enough to add proper comment. Signed-off-by: Denis V. Lunev <den@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[NET]: Move hardware header operations out of netdevice.Stephen Hemminger
Since hardware header operations are part of the protocol class not the device instance, make them into a separate object and save memory. Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[NET]: Remove no longer relevant comment in loopback driver.David S. Miller
It talks about __get_cpu_var() which the driver no longer does. Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[NET]: Make the loopback device per network namespace.Eric W. Biederman
This patch makes loopback_dev per network namespace. Adding code to create a different loopback device for each network namespace and adding the code to free a loopback device when a network namespace exits. This patch modifies all users the loopback_dev so they access it as init_net.loopback_dev, keeping all of the code compiling and working. A later pass will be needed to update the users to use something other than the initial network namespace. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[NET]: Dynamically allocate the per cpu counters for the loopback device.Eric W. Biederman
This patch add support for dynamically allocating the statistics counters for the loopback device and adds appropriate device methods for allocating and freeing the loopback device. This completes support for creating multiple instances of the loopback device, in preparation for creating per network namespace instances. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[NET]: Dynamically allocate the loopback device, part 2.Daniel Lezcano
Doing this makes loopback.c a better example of how to do a simple network device, and it removes the special case single static allocation of a struct net_device, hopefully making maintenance easier. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com> Acked-By: Kirill Korotaev <dev@sw.ru> Acked-by: Benjamin Thery <benjamin.thery@bull.net>
2007-10-10[NET]: Dynamically allocate the loopback device, part 1.Daniel Lezcano
This patch replaces all occurences to the static variable loopback_dev to a pointer loopback_dev. That provides the mindless, trivial, uninteressting change part for the dynamic allocation for the loopback. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com> Acked-By: Kirill Korotaev <dev@sw.ru> Acked-by: Benjamin Thery <benjamin.thery@bull.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[ETHTOOL] Provide default behaviors for a few ethtool sub-ioctlsJeff Garzik
For the operations get-tx-csum get-sg get-tso get-ufo the default ethtool_op_xxx behavior is fine for all drivers, so we permit op==NULL to imply the default behavior. This provides a more uniform behavior across all drivers, eliminating ethtool(8) "ioctl not supported" errors on older drivers that had not been updated for the latest sub-ioctls. The ethtool_op_xxx() functions are left exported, in case anyone wishes to call them directly from a driver-private implementation -- a not-uncommon case. Should an ethtool_op_xxx() helper remain unused for a while, except by net/core/ethtool.c, we can un-export it at a later date. [ Resolved conflicts with set/get value ethtool patch... -DaveM ] Signed-off-by: Jeff Garzik <jeff@garzik.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[NETNS]: Fix loopback network namespace initialization.Daniel Lezcano
The core patchset of the network namespace sent by Eric Biederman does not do dynamic loopback creation. So there is no call to alloc_netdev_mq which fills the network namespace field of the netdevice. This patch assign the loopback to the init network namespace. Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[NET]: Implement network device movement between namespacesEric W. Biederman
This patch introduces NETIF_F_NETNS_LOCAL a flag to indicate a network device is local to a single network namespace and should never be moved. Useful for pseudo devices that we need an instance in each network namespace (like the loopback device) and for any device we find that cannot handle multiple network namespaces so we may trap them in the initial network namespace. This patch introduces the function dev_change_net_namespace a function used to move a network device from one network namespace to another. To the network device nothing special appears to happen, to the components of the network stack it appears as if the network device was unregistered in the network namespace it is in, and a new device was registered in the network namespace the device was moved to. This patch sets up a namespace device destructor that upon the exit of a network namespace moves all of the movable network devices to the initial network namespace so they are not lost. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-31[NET] loopback: Panic if registration failsHerbert Xu
Because IPv4 and IPv6 both depend on the presence of the loopback device to function, failure in registration the loopback device should be fatal. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[NET]: loopback driver can use loopback_dev integrated net_device_statsEric Dumazet
Rusty added a new 'stats' field to struct net_device. loopback driver can use it instead of declaring another struct net_device_stats This saves some memory. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF]: Introduce skb_copy_to_linear_data{_offset}Arnaldo Carvalho de Melo
To clearly state the intent of copying to linear sk_buffs, _offset being a overly long variant but interesting for the sake of saving some bytes. Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
2007-04-25[SK_BUFF]: Introduce ip_hdr(), remove skb->nh.iphArnaldo Carvalho de Melo
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF]: Introduce skb_network_header()Arnaldo Carvalho de Melo
For the places where we need a pointer to the network header, it is still legal to touch skb->nh.raw directly if just adding to, subtracting from or setting it to another layer header. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF]: Introduce skb_reset_network_header(skb)Arnaldo Carvalho de Melo
For the common, open coded 'skb->nh.raw = skb->data' operation, so that we can later turn skb->nh.raw into a offset, reducing the size of struct sk_buff in 64bit land while possibly keeping it as a pointer on 32bit. This one touches just the most simple case, next will handle the slightly more "complex" cases. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF]: Introduce skb_set_mac_header()Arnaldo Carvalho de Melo
For the cases where we want to set skb->mac.raw to an offset from skb->data. Simple cases first, the memmove ones and specially pktgen will be left for later. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[ETH]: Make eth_type_trans set skb->dev like the other *_type_transArnaldo Carvalho de Melo
One less thing for drivers writers to worry about. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-01-03[NET] drivers/net/loopback.c: convert to module_init()Adrian Bunk
This patch converts drivers/net/loopback.c to using module_init(). Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-10-20[NET]: Can use __get_cpu_var() instead of per_cpu() in loopback driver.Eric Dumazet
As BHs are off in loopback_xmit(), preemption cannot occurs, so we can use __get_cpu_var() instead of per_cpu() (and avoid a preempt_enable()/preempt_disable() pair) Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-10-18[NET]: reduce per cpu ram used for loopback statsEric Dumazet
We dont need a full struct net_device_stats (currently 23 long : 184 bytes on x86_64) per possible CPU, but only two counters : bytes and packets We save few CPU cycles too in loopback_xmit() not updating 4 fields, but 2. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-28[NET] loopback: minor statistics optimizationStephen Hemminger
The loopback device status structure is a singleton and doesn't need to be allocated. Add ethtool_ops hooks to show checksum always on, and make ethtool_ops const. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-13drivers/net: const-ify ethtool_ops declarationsJeff Garzik
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-13drivers/net: Trim trailing whitespaceJeff Garzik
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-07-08[NET] gso: Add skb_is_gsoHerbert Xu
This patch adds the wrapper function skb_is_gso which can be used instead of directly testing skb_shinfo(skb)->gso_size. This makes things a little nicer and allows us to change the primary key for indicating whether an skb is GSO (if we ever want to do that). Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-23[NET]: Merge TSO/UFO fields in sk_buffHerbert Xu
Having separate fields in sk_buff for TSO/UFO (tso_size/ufo_size) is not going to scale if we add any more segmentation methods (e.g., DCCP). So let's merge them. They were used to tell the protocol of a packet. This function has been subsumed by the new gso_type field. This is essentially a set of netdev feature bits (shifted by 16 bits) that are required to process a specific skb. As such it's easy to tell whether a given device can process a GSO skb: you just have to and the gso_type field and the netdev's features field. I've made gso_type a conjunction. The idea is that you have a base type (e.g., SKB_GSO_TCPV4) that can be modified further to support new features. For example, if we add a hardware TSO type that supports ECN, they would declare NETIF_F_TSO | NETIF_F_TSO_ECN. All TSO packets with CWR set would have a gso_type of SKB_GSO_TCPV4 | SKB_GSO_TCPV4_ECN while all other TSO packets would be SKB_GSO_TCPV4. This means that only the CWR packets need to be emulated in software. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-28[PATCH] for_each_possible_cpu: loopback device.KAMEZAWA Hiroyuki
This patch replaces for_each_cpu with for_each_possible_cpu. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] more for_each_cpu() conversionsAndrew Morton
When we stop allocating percpu memory for not-possible CPUs we must not touch the percpu data for not-possible CPUs at all. The correct way of doing this is to test cpu_possible() or to use for_each_cpu(). This patch is a kernel-wide sweep of all instances of NR_CPUS. I found very few instances of this bug, if any. But the patch converts lots of open-coded test to use the preferred helper macros. Cc: Mikael Starvik <starvik@axis.com> Cc: David Howells <dhowells@redhat.com> Acked-by: Kyle McMartin <kyle@parisc-linux.org> Cc: Anton Blanchard <anton@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: Andi Kleen <ak@muc.de> Cc: Christian Zankel <chris@zankel.net> Cc: Philippe Elie <phil.el@wanadoo.fr> Cc: Nathan Scott <nathans@sgi.com> Cc: Jens Axboe <axboe@suse.de> Cc: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-18Merge /spare/repo/linux-2.6/Jeff Garzik