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2011-12-05net: Rename dst_get_neighbour{, _raw} to dst_get_neighbour_noref{, _raw}.David Miller
To reflect the fact that a refrence is not obtained to the resulting neighbour entry. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Roland Dreier <roland@purestorage.com>
2011-12-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2011-11-30sch_teql: fix lockdep splatEric Dumazet
We need rcu_read_lock() protection before using dst_get_neighbour(), and we must cache its value (pass it to __teql_resolve()) teql_master_xmit() is called under rcu_read_lock_bh() protection, its not enough. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-29net: Add queue state xoff flag for stackTom Herbert
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>
2011-07-17net: Abstract dst->neighbour accesses behind helpers.David S. Miller
dst_{get,set}_neighbour() Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-24Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: net/sched/sch_hfsc.c net/sched/sch_htb.c net/sched/sch_tbf.c
2011-01-20net_sched: accurate bytes/packets stats/ratesEric Dumazet
In commit 44b8288308ac9d (net_sched: pfifo_head_drop problem), we fixed a problem with pfifo_head drops that incorrectly decreased sch->bstats.bytes and sch->bstats.packets Several qdiscs (CHOKe, SFQ, pfifo_head, ...) are able to drop a previously enqueued packet, and bstats cannot be changed, so bstats/rates are not accurate (over estimated) This patch changes the qdisc_bstats updates to be done at dequeue() time instead of enqueue() time. bstats counters no longer account for dropped frames, and rates are more correct, since enqueue() bursts dont have effect on dequeue() rate. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-19net_sched: cleanupsEric Dumazet
Cleanup net/sched code to current CodingStyle and practices. Reduce inline abuse Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-13net: remove dev_txq_stats_fold()Eric Dumazet
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 ab35cd4b8f42 (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>
2011-01-10net_sched: factorize qdisc stats handlingEric Dumazet
HTB takes into account skb is segmented in stats updates. Generalize this to all schedulers. They should use qdisc_bstats_update() helper instead of manipulating bstats.bytes and bstats.packets Add bstats_update() helper too for classes that use gnet_stats_basic_packed fields. Note : Right now, TCQ_F_CAN_BYPASS shortcurt can be taken only if no stab is setup on qdisc. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-28net: add netif_tx_queue_frozen_or_stoppedEric Dumazet
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>
2010-10-11neigh: Protect neigh->ha[] with a seqlockEric Dumazet
Add a seqlock in struct neighbour to protect neigh->ha[], and avoid dirtying neighbour in stress situation (many different flows / dsts) Dirtying takes place because of read_lock(&n->lock) and n->used writes. Switching to a seqlock, and writing n->used only on jiffies changes permits less dirtying. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-10net: Use NET_XMIT_SUCCESS where possible.Ben Greear
This is based on work originally done by Patric McHardy. Signed-off-by: Ben Greear <greearb@candelatech.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-16Clear IFF_XMIT_DST_RELEASE for teql interfacesTom Hughes
https://bugzilla.kernel.org/show_bug.cgi?id=16183 The sch_teql module, which can be used to load balance over a set of underlying interfaces, stopped working after 2.6.30 and has been broken in all kernels since then for any underlying interface which requires the addition of link level headers. The problem is that the transmit routine relies on being able to access the destination address in the skb in order to do address resolution once it has decided which underlying interface it is going to transmit through. In 2.6.31 the IFF_XMIT_DST_RELEASE flag was introduced, and set by default for all interfaces, which causes the destination address to be released before the transmit routine for the interface is called. The solution is to clear that flag for teql interfaces. Signed-off-by: Tom Hughes <tom@compton.nu> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2009-11-29net: Move && and || to end of previous lineJoe Perches
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>
2009-09-01netdev: convert pseudo-devices to netdev_tx_tStephen Hemminger
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-05net: use NETDEV_TX_OK instead of 0 in ndo_start_xmit() functionsPatrick McHardy
This patch is the result of an automatic spatch transformation to convert all ndo_start_xmit() return values of 0 to NETDEV_TX_OK. Some occurences are missed by the automatic conversion, those will be handled in a seperate patch. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-13net: use symbolic values for ndo_start_xmit() return codesPatrick McHardy
Convert magic values 1 and -1 to NETDEV_TX_BUSY and NETDEV_TX_LOCKED respectively. 0 (NETDEV_TX_OK) is not changed to keep the noise down, except in very few cases where its in direct proximity to one of the other values. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-03net: skb->dst accessorsEric Dumazet
Define three accessors to get/set dst attached to a skb struct dst_entry *skb_dst(const struct sk_buff *skb) void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) void skb_dst_drop(struct sk_buff *skb) This one should replace occurrences of : dst_release(skb->dst) skb->dst = NULL; Delete skb->dst field Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-25net: txq_trans_update() helperEric Dumazet
We would like to get rid of netdev->trans_start = jiffies; that about all net drivers have to use in their start_xmit() function, and use txq->trans_start instead. This can be done generically in core network, as suggested by David. Some devices, (particularly loopback) dont need trans_start update, because they dont have transmit watchdog. We could add a new device flag, or rely on fact that txq->tran_start can be updated is txq->xmit_lock_owner is different than -1. Use a helper function to hide our choice. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-19sch_teql: Use net_device internal statsEric Dumazet
We can slightly reduce size of teqlN structure, not duplicating stats structure in teql_master but using stats field from net_device.stats for tx_errors and from netdev_queue for tx_bytes/tx_packets/tx_dropped values. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-18sch_teql: should not dereference skb after ndo_start_xmit()Eric Dumazet
It is illegal to dereference a skb after a successful ndo_start_xmit() call. We must store skb length in a local variable instead. Bug was introduced in 2.6.27 by commit 0abf77e55a2459aa9905be4b226e4729d5b4f0cb (net_sched: Add accessor function for packet length for qdiscs) Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-06sch_teql: convert to net_device_opsStephen Hemminger
Convert this driver to net_device_ops. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-13pkt_sched: Remove qdisc->ops->requeue() etc.Jarek Poplawski
After implementing qdisc->ops->peek() and changing sch_netem into classless qdisc there are no more qdisc->ops->requeue() users. This patch removes this method with its wrappers (qdisc_requeue()), and also unused qdisc->requeue structure. There are a few minor fixes of warnings (htb_enqueue()) and comments btw. The idea to kill ->requeue() and a similar patch were first developed by David S. Miller. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-31pkt_sched: Add qdisc->ops->peek() implementation.Jarek Poplawski
Add qdisc->ops->peek() implementation for work-conserving qdiscs. With feedback from Patrick McHardy. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-29pkt_sched: Fix locking of qdisc_root with qdisc_root_sleeping_lock()Jarek Poplawski
Use qdisc_root_sleeping_lock() instead of qdisc_root_lock() where appropriate. The only difference is while dev is deactivated, when currently we can use a sleeping qdisc with the lock of noop_qdisc. This shouldn't be dangerous since after deactivation root lock could be used only by gen_estimator code, but looks wrong anyway. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-31netdev: Fix lockdep warnings in multiqueue configurations.David S. Miller
When support for multiple TX queues were added, the netif_tx_lock() routines we converted to iterate over all TX queues and grab each queue's spinlock. This causes heartburn for lockdep and it's not a healthy thing to do with lots of TX queues anyways. So modify this to use a top-level lock and a "frozen" state for the individual TX queues. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-20net_sched: Add accessor function for packet length for qdiscsJussi Kivilinna
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-17pkt_sched: Kill netdev_queue lock.David S. Miller
We can simply use the qdisc->q.lock for all of the qdisc tree synchronization. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-17net: Use queue aware tests throughout.David S. Miller
This effectively "flips the switch" by making the core networking and multiqueue-aware drivers use the new TX multiqueue structures. Non-multiqueue drivers need no changes. The interfaces they use such as netif_stop_queue() degenerate into an operation on TX queue zero. So everything "just works" for them. Code that really wants to do "X" to all TX queues now invokes a routine that does so, such as netif_tx_wake_all_queues(), netif_tx_stop_all_queues(), etc. pktgen and netpoll required a little bit more surgery than the others. In particular the pktgen changes, whilst functional, could be largely improved. The initial check in pktgen_xmit() will sometimes check the wrong queue, which is mostly harmless. The thing to do is probably to invoke fill_packet() earlier. The bulk of the netpoll changes is to make the code operate solely on the TX queue indicated by by the SKB queue mapping. Setting of the SKB queue mapping is entirely confined inside of net/core/dev.c:dev_pick_tx(). If we end up needing any kind of special semantics (drops, for example) it will be implemented here. Finally, we now have a "real_num_tx_queues" which is where the driver indicates how many TX queues are actually active. With IGB changes from Jeff Kirsher. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-17netdev: Allocate multiple queues for TX.David S. Miller
alloc_netdev_mq() now allocates an array of netdev_queue structures for TX, based upon the queue_count argument. Furthermore, all accesses to the TX queues are now vectored through the netdev_get_tx_queue() and netdev_for_each_tx_queue() interfaces. This makes it easy to grep the tree for all things that want to get to a TX queue of a net device. Problem spots which are not really multiqueue aware yet, and only work with one queue, can easily be spotted by grepping for all netdev_get_tx_queue() calls that pass in a zero index. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-08netdev: Move rest of qdisc state into struct netdev_queueDavid S. Miller
Now qdisc, qdisc_sleeping, and qdisc_list also live there. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-08netdev: Move queue_lock into struct netdev_queue.David S. Miller
The lock is now an attribute of the device queue. One thing to notice is that "suspicious" places emerge which will need specific training about multiple queue handling. They are so marked with explicit "netdev->rx_queue" and "netdev->tx_queue" references. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-08pkt_sched: Remove 'dev' member of struct Qdisc.David S. Miller
It can be obtained via the netdev_queue. So create a helper routine, qdisc_dev(), to make the transformations nicer looking. Now, qdisc_alloc() now no longer needs a net_device pointer argument. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-31[PKT_SCHED] sch_teql.c: Duplicate IFF_BROADCAST in FMASK, remove 2nd.Roel Kluin
Signed-off-by: Roel Kluin <12o3l@tiscali.nl> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[NET_SCHED]: Convert packet schedulers from rtnetlink to new netlink APIPatrick McHardy
Convert packet schedulers to use the netlink API. Unfortunately a gradual conversion is not possible without breaking compilation in the middle or adding lots of casts, so this patch converts them all in one step. The patch has been mostly generated automatically with some minor edits to at least allow seperate conversion of classifiers and actions. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-07[PKT_SCHED]: Fix OOPS when removing devices from a teql queuing disciplineEvgeniy Polyakov
tecl_reset() is called from deactivate and qdisc is set to noop already, but subsequent teql_xmit does not know about it and dereference private data as teql qdisc and thus oopses. not catch it first :) Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-22[NET]: Hide the queue_mapping field inside netif_subqueue_stoppedPavel Emelyanov
Many places get the queue_mapping field from skb to pass it to the netif_subqueue_stopped() which will be 0 in any case. Make the helper that works with sk_buff Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-22[NET]: Make and use skb_get_queue_mappingPavel Emelyanov
Make the helper for getting the field, symmetrical to the "set" one. Return 0 if CONFIG_NETDEVICES_MULTIQUEUE=n Signed-off-by: Pavel Emelyanov <xemul@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]: Wrap netdevice hardware header creation.Stephen Hemminger
Add inline for common usage of hardware header creation, and fix bug in IPV6 mcast where the assumption about negative return is an errno. Negative return from hard_header means not enough space was available,(ie -N bytes). Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[NET]: Nuke SET_MODULE_OWNER macro.Ralf Baechle
It's been a useless no-op for long enough in 2.6 so I figured it's time to remove it. The number of people that could object because they're maintaining unified 2.4 and 2.6 drivers is probably rather small. [ Handled drivers added by netdev tree and some missed IRDA cases... -DaveM ] Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Jeff Garzik <jeff@garzik.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-10[NET_SCHED]: Remove unnecessary includesPatrick McHardy
Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-10[CORE] Stack changes to add multiqueue hardware support APIPeter P Waskiewicz Jr
Add the multiqueue hardware device support API to the core network stack. Allow drivers to allocate multiple queues and manage them at the netdev level if they choose to do so. Added a new field to sk_buff, namely queue_mapping, for drivers to know which tx_ring to select based on OS classification of the flow. Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-05-10[NET_SCHED]: teql_enqueue can check limits before skb enqueueKrishna Kumar
Optimize teql_enqueue so that it first checks limits before enqueing. Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF]: Introduce skb_network_offset()Arnaldo Carvalho de Melo
For the quite common 'skb->nh.raw - skb->data' sequence. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-14[PATCH] remove many unneeded #includes of sched.hTim Schmielau
After Al Viro (finally) succeeded in removing the sched.h #include in module.h recently, it makes sense again to remove other superfluous sched.h includes. There are quite a lot of files which include it but don't actually need anything defined in there. Presumably these includes were once needed for macros that used to live in sched.h, but moved to other header files in the course of cleaning it up. To ease the pain, this time I did not fiddle with any header files and only removed #includes from .c-files, which tend to cause less trouble. Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha, arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig, allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all configs in arch/arm/configs on arm. I also checked that no new warnings were introduced by the patch (actually, some warnings are removed that were emitted by unnecessarily included header files). Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-10[NET] SCHED: Fix whitespace errors.YOSHIFUJI Hideaki
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17[NET]: Add netif_tx_lockHerbert Xu
Various drivers use xmit_lock internally to synchronise with their transmission routines. They do so without setting xmit_lock_owner. This is fine as long as netpoll is not in use. With netpoll it is possible for deadlocks to occur if xmit_lock_owner isn't set. This is because if a printk occurs while xmit_lock is held and xmit_lock_owner is not set can cause netpoll to attempt to take xmit_lock recursively. While it is possible to resolve this by getting netpoll to use trylock, it is suboptimal because netpoll's sole objective is to maximise the chance of getting the printk out on the wire. So delaying or dropping the message is to be avoided as much as possible. So the only alternative is to always set xmit_lock_owner. The following patch does this by introducing the netif_tx_lock family of functions that take care of setting/unsetting xmit_lock_owner. I renamed xmit_lock to _xmit_lock to indicate that it should not be used directly. I didn't provide irq versions of the netif_tx_lock functions since xmit_lock is meant to be a BH-disabling lock. This is pretty much a straight text substitution except for a small bug fix in winbond. It currently uses netif_stop_queue/spin_unlock_wait to stop transmission. This is unsafe as an IRQ can potentially wake up the queue. So it is safer to use netif_tx_disable. The hamradio bits used spin_lock_irq but it is unnecessary as xmit_lock must never be taken in an IRQ handler. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>