- 16 6月, 2010 3 次提交
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由 Herbert Xu 提交于
As it stands, netpoll_setup and netpoll_cleanup have no locking protection whatsoever. So chaos ensures if two entities try to perform them on the same device. This patch adds RTNL to the equation. The code has been rearranged so that bits that do not need RTNL protection are now moved to the top of netpoll_setup. Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Herbert Xu 提交于
The use of RCU in netpoll is incorrect in a number of places: 1) The initial setting is lacking a write barrier. 2) The synchronize_rcu is in the wrong place. 3) Read barriers are missing. 4) Some places are even missing rcu_read_lock. 5) npinfo is zeroed after freeing. This patch fixes those issues. As most users are in BH context, this also converts the RCU usage to the BH variant. Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au> Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Herbert Xu 提交于
Since we have to NULL npinfo regardless of whether there is a ndo_netpoll_cleanup, it makes sense to do this unconditionally in netpoll_cleanup rather than having every driver do it by themselves. Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 31 5月, 2010 1 次提交
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由 Eric Dumazet 提交于
netpoll does an interesting work in zap_completion_queue(), but this was before we did skb orphaning before delivering packets to device. It now makes sense to add a test in dev_kfree_skb_irq() to not queue a skb if already orphaned, and to remove netpoll zap_completion_queue() as a bonus. Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 06 5月, 2010 1 次提交
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由 WANG Cong 提交于
This whole patchset is for adding netpoll support to bridge and bonding devices. I already tested it for bridge, bonding, bridge over bonding, and bonding over bridge. It looks fine now. To make bridge and bonding support netpoll, we need to adjust some netpoll generic code. This patch does the following things: 1) introduce two new priv_flags for struct net_device: IFF_IN_NETPOLL which identifies we are processing a netpoll; IFF_DISABLE_NETPOLL is used to disable netpoll support for a device at run-time; 2) introduce one new method for netdev_ops: ->ndo_netpoll_cleanup() is used to clean up netpoll when a device is removed. 3) introduce netpoll_poll_dev() which takes a struct net_device * parameter; export netpoll_send_skb() and netpoll_poll_dev() which will be used later; 4) hide a pointer to struct netpoll in struct netpoll_info, ditto. 5) introduce ->real_dev for struct netpoll. 6) introduce a new status NETDEV_BONDING_DESLAE, which is used to disable netconsole before releasing a slave, to avoid deadlocks. Cc: David Miller <davem@davemloft.net> Cc: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: NWANG Cong <amwang@redhat.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 30 3月, 2010 1 次提交
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由 Tejun Heo 提交于
include cleanup: Update gfp.h and slab.h includes to prepare for breaking 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: NTejun Heo <tj@kernel.org> Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
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- 23 3月, 2010 1 次提交
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由 Amerigo Wang 提交于
v2: update according to Frans' comments. Currently, if we leave spaces before dst port, netconsole will silently accept it as 0. Warn about this. Also, when spaces appear in other places, make them visible in error messages. Signed-off-by: NWANG Cong <amwang@redhat.com> Cc: David Miller <davem@davemloft.net> Acked-by: NNeil Horman <nhorman@tuxdriver.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 17 3月, 2010 1 次提交
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由 Jiri Slaby 提交于
Stanse found that one error path in netpoll_setup dereferences npinfo even though it is NULL. Avoid that by adding new label and go to that instead. Signed-off-by: NJiri Slaby <jslaby@suse.cz> Cc: Daniel Borkmann <danborkmann@googlemail.com> Cc: David S. Miller <davem@davemloft.net> Acked-by: chavey@google.com Acked-by: NMatt Mackall <mpm@selenic.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 14 1月, 2010 1 次提交
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由 Daniel Borkmann 提交于
Signed-off-by: NDaniel Borkmann <danborkmann@googlemail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 24 8月, 2009 1 次提交
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由 Dongdong Deng 提交于
WARN_ONCE for ndo_start_xmit() enable interrupts in netpoll_send_skb(), because the NETPOLL API requires that interrupts remain disabled in netpoll_send_skb(). Signed-off-by: NDongdong Deng <dongdong.deng@windriver.com> Acked-by: NMatt Mackall <mpm@selenic.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 09 7月, 2009 2 次提交
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由 Anton Vorontsov 提交于
Using early netconsole and gianfar driver this error pops up: netconsole: timeout waiting for carrier It appears that net/core/netpoll.c:netpoll_setup() is using cond_resched() in a loop waiting for a carrier. The thing is that cond_resched() is a no-op when system_state != SYSTEM_RUNNING, and so drivers/net/phy/phy.c's state_queue is never scheduled, therefore link detection doesn't work. I belive that the main problem is in cond_resched()[1], but despite how the cond_resched() story ends, it might be a good idea to call msleep(1) instead of cond_resched(), as suggested by Andrew Morton. [1] http://lkml.org/lkml/2009/7/7/463Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Anton Vorontsov 提交于
Some PHYs require longer timeouts for carrier detection, and auto-negotiation process may take indefinite amount of time. It may be inconvenient to force longer timeouts for sane PHYs, so let's introduce a kernel command line option. Since we're using module_param(), the option also can be changed in runtime. Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 26 5月, 2009 1 次提交
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由 Eric Dumazet 提交于
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: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 22 5月, 2009 2 次提交
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由 David S. Miller 提交于
Reproted by Stephen Rothwell. Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Neil Horman 提交于
Patch to add the ability to detect drops in hardware interfaces via dropwatch. Adds a tracepoint to net_rx_action to signal everytime a napi instance is polled. The dropmon code then periodically checks to see if the rx_frames counter has changed, and if so, adds a drop notification to the netlink protocol, using the reserved all-0's vector to indicate the drop location was in hardware, rather than somewhere in the code. Signed-off-by: NNeil Horman <nhorman@tuxdriver.com> include/linux/net_dropmon.h | 8 ++ include/trace/napi.h | 11 +++ net/core/dev.c | 5 + net/core/drop_monitor.c | 124 ++++++++++++++++++++++++++++++++++++++++++-- net/core/net-traces.c | 4 + net/core/netpoll.c | 2 6 files changed, 149 insertions(+), 5 deletions(-) Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 18 5月, 2009 1 次提交
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由 Pavel Emelyanov 提交于
It looks like the dev in netpoll_poll can be NULL - at lease it's checked at the function beginning. Thus the dev->netde_ops dereference looks dangerous. Signed-off-by: NPavel Emelyanov <xemul@openvz.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 29 3月, 2009 1 次提交
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由 Harvey Harrison 提交于
Allows for the removal of byteswapping in some places and the removal of HIPQUAD (replaced by %pI4). Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 10 12月, 2008 1 次提交
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由 Neil Horman 提交于
A few months back a race was discused between the netpoll napi service path, and the fast path through net_rx_action: http://kerneltrap.org/mailarchive/linux-netdev/2007/10/16/345470 A patch was submitted for that bug, but I think we missed a case. Consider the following scenario: INITIAL STATE CPU0 has one napi_struct A on its poll_list CPU1 is calling netpoll_send_skb and needs to call poll_napi on the same napi_struct A that CPU0 has on its list CPU0 CPU1 net_rx_action poll_napi !list_empty (returns true) locks poll_lock for A poll_one_napi napi->poll netif_rx_complete __napi_complete (removes A from poll_list) list_entry(list->next) In the above scenario, net_rx_action assumes that the per-cpu poll_list is exclusive to that cpu. netpoll of course violates that, and because the netpoll path can dequeue from the poll list, its possible for CPU0 to detect a non-empty list at the top of the while loop in net_rx_action, but have it become empty by the time it calls list_entry. Since the poll_list isn't surrounded by any other structure, the returned data from that list_entry call in this situation is garbage, and any number of crashes can result based on what exactly that garbage is. Given that its not fasible for performance reasons to place exclusive locks arround each cpus poll list to provide that mutal exclusion, I think the best solution is modify the netpoll path in such a way that we continue to guarantee that the poll_list for a cpu is in fact exclusive to that cpu. To do this I've implemented the patch below. It adds an additional bit to the state field in the napi_struct. When executing napi->poll from the netpoll_path, this bit will be set. When a driver calls netif_rx_complete, if that bit is set, it will not remove the napi_struct from the poll_list. That work will be saved for the next iteration of net_rx_action. I've tested this and it seems to work well. About the biggest drawback I can see to it is the fact that it might result in an extra loop through net_rx_action in the event that the device is actually contended for (i.e. the netpoll path actually preforms all the needed work no the device, and the call to net_rx_action winds up doing nothing, except removing the napi_struct from the poll_list. However I think this is probably a small price to pay, given that the alternative is a crash. Signed-off-by: NNeil Horman <nhorman@tuxdriver.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 21 11月, 2008 1 次提交
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由 Stephen Hemminger 提交于
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: NStephen Hemminger <shemminger@vyatta.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 20 11月, 2008 2 次提交
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由 Stephen Hemminger 提交于
This patch changes the network device internal API to move adminstrative operations out of the network device structure and into a separate structure. This patch involves some hackery to maintain compatablity between the new and old model, so all 300+ drivers don't have to be changed at once. For drivers that aren't converted yet, the netdevice_ops virt function list still resides in the net_device structure. For old protocols, the new net_device_ops are copied out to the old net_device pointers. After the transistion is completed the nag message can be changed to an WARN_ON, and the compatiablity code can be made configurable. Some function pointers aren't moved: * destructor can't be in net_device_ops because it may need to be referenced after the module is unloaded. * neighbor setup is manipulated in a couple of places that need special consideration * hard_start_xmit is in the fast path for transmit. Signed-off-by: NStephen Hemminger <shemminger@vyatta.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Joe Perches 提交于
The first argument to csum_partial is const void * casts to char/u8 * are not necessary Signed-off-by: NJoe Perches <joe@perches.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 28 10月, 2008 1 次提交
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由 Johannes Berg 提交于
This converts pretty much everything to print_mac. There were a few things that had conflicts which I have just dropped for now, no harm done. I've built an allyesconfig with this and looked at the files that weren't built very carefully, but it's a huge patch. Signed-off-by: NJohannes Berg <johannes@sipsolutions.net> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 01 8月, 2008 1 次提交
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由 David S. Miller 提交于
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: NDavid S. Miller <davem@davemloft.net>
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- 18 7月, 2008 1 次提交
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由 David S. Miller 提交于
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: NDavid S. Miller <davem@davemloft.net>
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- 13 5月, 2008 1 次提交
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由 Johannes Berg 提交于
This patch adds needed_headroom/needed_tailroom members to struct net_device and updates many places that allocate sbks to use them. Not all of them can be converted though, and I'm sure I missed some (I mostly grepped for LL_RESERVED_SPACE) Signed-off-by: NJohannes Berg <johannes@sipsolutions.net> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 21 3月, 2008 1 次提交
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由 Jarek Poplawski 提交于
zap_completion_queue() retrieves skbs from completion_queue where they have zero skb->users counter. Before dev_kfree_skb_any() it should be non-zero yet, so it's increased now. Reported-and-tested-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NJarek Poplawski <jarkao2@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 05 3月, 2008 1 次提交
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由 David S. Miller 提交于
Based upon a report by Andrew Morton and code analysis done by Jarek Poplawski. This reverts 33f807ba ("[NETPOLL]: Kill NETPOLL_RX_DROP, set but never tested.") and c7b6ea24 ("[NETPOLL]: Don't need rx_flags."). The rx_flags did get tested for zero vs. non-zero and therefore we do need those tests and that code which sets NETPOLL_RX_DROP et al. Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 04 3月, 2008 1 次提交
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由 Pavel Emelyanov 提交于
There are some place, that calculate the ARP header length. These calculations are correct, but a) some operate with "magic" constants, b) enlarge the code length (sometimes at the cost of coding style), c) are not informative from the first glance. The proposal is to introduce a helper, that includes all the good sides of these calculations. Signed-off-by: NPavel Emelyanov <xemul@openvz.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 29 1月, 2008 6 次提交
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由 Joe Perches 提交于
Signed-off-by: NJoe Perches <joe@perches.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Stephen Hemminger 提交于
The rx_flags variable is redundant. Turning rx on/off is done via setting the rx_np pointer. Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Stephen Hemminger 提交于
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Stephen Hemminger 提交于
The local_mac is managed by the network device, no need to keep a spare copy and all the management problems that could cause. Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Stephen Hemminger 提交于
Restructure code slightly to improve readability: * dereference device once * change obvious while() loop * let poll_napi() handle null list itself Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Stephen Hemminger 提交于
Use standard routine for flushing queue. Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 30 10月, 2007 1 次提交
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由 David S. Miller 提交于
netpoll_poll_lock() synchronizes the ->poll() invocation code paths, but once we have the lock we have to make sure that NAPI_STATE_SCHED is still set. Otherwise we get: cpu 0 cpu 1 net_rx_action() poll_napi() netpoll_poll_lock() ... spin on ->poll_lock ->poll() netif_rx_complete netpoll_poll_unlock() acquire ->poll_lock() ->poll() netif_rx_complete() CRASH Based upon a bug report from Tina Yang. Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 22 10月, 2007 1 次提交
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由 Pavel Emelyanov 提交于
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: NPavel Emelyanov <xemul@openvz.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 11 10月, 2007 4 次提交
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由 Stephen Hemminger 提交于
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: NStephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Joe Perches 提交于
This is nicer than the MAC_FMT stuff. Signed-off-by: NJoe Perches <joe@perches.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Eric W. Biederman 提交于
This patch makes most of the generic device layer network namespace safe. This patch makes dev_base_head a network namespace variable, and then it picks up a few associated variables. The functions: dev_getbyhwaddr dev_getfirsthwbytype dev_get_by_flags dev_get_by_name __dev_get_by_name dev_get_by_index __dev_get_by_index dev_ioctl dev_ethtool dev_load wireless_process_ioctl were modified to take a network namespace argument, and deal with it. vlan_ioctl_set and brioctl_set were modified so their hooks will receive a network namespace argument. So basically anthing in the core of the network stack that was affected to by the change of dev_base was modified to handle multiple network namespaces. The rest of the network stack was simply modified to explicitly use &init_net the initial network namespace. This can be fixed when those components of the network stack are modified to handle multiple network namespaces. For now the ifindex generator is left global. Fundametally ifindex numbers are per namespace, or else we will have corner case problems with migration when we get that far. At the same time there are assumptions in the network stack that the ifindex of a network device won't change. Making the ifindex number global seems a good compromise until the network stack can cope with ifindex changes when you change namespaces, and the like. Signed-off-by: NEric W. Biederman <ebiederm@xmission.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Satyam Sharma 提交于
Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>. This patch introduces support for dynamic reconfiguration (adding, removing and/or modifying parameters of netconsole targets at runtime) using a userspace interface exported via configfs. Documentation is also updated accordingly. Issues and brief design overview: (1) Kernel-initiated creation / destruction of kernel objects is not possible with configfs -- the lifetimes of the "config items" is managed exclusively from userspace. But netconsole must support boot/module params too, and these are parsed in kernel and hence netpolls must be setup from the kernel. Joel Becker suggested to separately manage the lifetimes of the two kinds of netconsole_target objects -- those created via configfs mkdir(2) from userspace and those specified from the boot/module option string. This adds complexity and some redundancy here and also means that boot/module param-created targets are not exposed through the configfs namespace (and hence cannot be updated / destroyed dynamically). However, this saves us from locking / refcounting complexities that would need to be introduced in configfs to support kernel-initiated item creation / destroy there. (2) In configfs, item creation takes place in the call chain of the mkdir(2) syscall in the driver subsystem. If we used an ioctl(2) to create / destroy objects from userspace, the special userspace program is able to fill out the structure to be passed into the ioctl and hence specify attributes such as local interface that are required at the time we set up the netpoll. For configfs, this information is not available at the time of mkdir(2). So, we keep all newly-created targets (via configfs) disabled by default. The user is expected to set various attributes appropriately (including the local network interface if required) and then write(2) "1" to the "enabled" attribute. Thus, netpoll_setup() is then called on the set parameters in the context of _this_ write(2) on the "enabled" attribute itself. This design enables the user to reconfigure existing netconsole targets at runtime to be attached to newly-come-up interfaces that may not have existed when netconsole was loaded or when the targets were actually created. All this effectively enables us to get rid of custom ioctls. (3) Ultra-paranoid configfs attribute show() and store() operations, with sanity and input range checking, using only safe string primitives, and compliant with the recommendations in Documentation/filesystems/sysfs.txt. (4) A new function netpoll_print_options() is created in the netpoll API, that just prints out the configured parameters for a netpoll structure. netpoll_parse_options() is modified to use that and it is also exported to be used from netconsole. Signed-off-by: NSatyam Sharma <satyam@infradead.org> Acked-by: NKeiichi Kii <k-keiichi@bx.jp.nec.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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