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2009-11-18linkwatch: linkwatch_forget_dev() to speedup device dismantleEric Dumazet
Herbert Xu a écrit : > On Tue, Nov 17, 2009 at 04:26:04AM -0800, David Miller wrote: >> Really, the link watch stuff is just due for a redesign. I don't >> think a simple hack is going to cut it this time, sorry Eric :-) > > I have no objections against any redesigns, but since the only > caller of linkwatch_forget_dev runs in process context with the > RTNL, it could also legally emit those events. Thanks guys, here an updated version then, before linkwatch surgery ? In this version, I force the event to be sent synchronously. [PATCH net-next-2.6] linkwatch: linkwatch_forget_dev() to speedup device dismantle time ip link del eth3.103 ; time ip link del eth3.104 ; time ip link del eth3.105 real 0m0.266s user 0m0.000s sys 0m0.001s real 0m0.770s user 0m0.000s sys 0m0.000s real 0m1.022s user 0m0.000s sys 0m0.000s One problem of current schem in vlan dismantle phase is the holding of device done by following chain : vlan_dev_stop() -> netif_carrier_off(dev) -> linkwatch_fire_event(dev) -> dev_hold() ... And __linkwatch_run_queue() runs up to one second later... A generic fix to this problem is to add a linkwatch_forget_dev() method to unlink the device from the list of watched devices. dev->link_watch_next becomes dev->link_watch_list (and use a bit more memory), to be able to unlink device in O(1). After patch : time ip link del eth3.103 ; time ip link del eth3.104 ; time ip link del eth3.105 real 0m0.024s user 0m0.000s sys 0m0.000s real 0m0.032s user 0m0.000s sys 0m0.001s real 0m0.033s user 0m0.000s sys 0m0.000s Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-08net: Clean up explicit ->tx_queue references in link watch.David S. Miller
First, we add a qdisc_tx_changing() helper which returns true if the qdisc attachment is in transition. Second, we remove an assertion warning which is of limited value and is hard to express precisely in a multiqueue environment. 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>
2007-05-10[NET] link_watch: Always schedule urgent eventsHerbert Xu
Urgent events may be delayed if we already have a non-urgent event queued for that device. This patch changes this by making sure that an urgent event is always looked at immediately. I've replaced the LW_RUNNING flag by LW_URGENT since whether work is scheduled is already kept track by the work queue system. The only complication is that we have to provide some exclusion for the setting linkwatch_nextevent which is available in the actual work function. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-05-10[NET] link_watch: Eliminate potential delay on wrap-aroundHerbert Xu
When the jiffies wrap around or when the system boots up for the first time, down events can be delayed indefinitely since we no longer update linkwatch_nextevent when only urgent events are processed. This patch fixes this by setting linkwatch_nextevent when a wrap-around occurs. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-05-10[NET]: Remove link_watch delay for up even when we're downHerbert Xu
Currently all link carrier events are delayed by up to a second before they're processed to prevent link storms. This causes unnecessary packet loss during that interval. In fact, we can achieve the same effect in preventing storms by only delaying down events and unnecssary up events. The latter is defined as up events when we're already up. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-05-10[NET] link_watch: Move link watch list into net_deviceHerbert Xu
These days the link watch mechanism is an integral part of the network subsystem as it manages the carrier status. So it now makes sense to allocate some memory for it in net_device rather than allocating it on demand. In fact, this is necessary because we can't tolerate a memory allocation failure since that means we'd have to potentially throw a link up event away. It also simplifies the code greatly. In doing so I discovered a subtle race condition in the use of singleevent. This race condition still exists (and is somewhat magnified) without singleevent but it's now plugged thanks to an smp_mb__before_clear_bit. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[NET]: cleanup extra semicolonsStephen Hemminger
Spring cleaning time... There seems to be a lot of places in the network code that have extra bogus semicolons after conditionals. Most commonly is a bogus semicolon after: switch() { } Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-10[NET] CORE: Fix whitespace errors.YOSHIFUJI Hideaki
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-11-22WorkStruct: Pass the work_struct pointer instead of context dataDavid Howells
Pass the work_struct pointer to the work function rather than context data. The work function can use container_of() to work out the data. For the cases where the container of the work_struct may go away the moment the pending bit is cleared, it is made possible to defer the release of the structure by deferring the clearing of the pending bit. To make this work, an extra flag is introduced into the management side of the work_struct. This governs auto-release of the structure upon execution. Ordinarily, the work queue executor would release the work_struct for further scheduling or deallocation by clearing the pending bit prior to jumping to the work function. This means that, unless the driver makes some guarantee itself that the work_struct won't go away, the work function may not access anything else in the work_struct or its container lest they be deallocated.. This is a problem if the auxiliary data is taken away (as done by the last patch). However, if the pending bit is *not* cleared before jumping to the work function, then the work function *may* access the work_struct and its container with no problems. But then the work function must itself release the work_struct by calling work_release(). In most cases, automatic release is fine, so this is the default. Special initiators exist for the non-auto-release case (ending in _NAR). Signed-Off-By: David Howells <dhowells@redhat.com>
2006-11-22WorkStruct: Separate delayable and non-delayable events.David Howells
Separate delayable work items from non-delayable work items be splitting them into a separate structure (delayed_work), which incorporates a work_struct and the timer_list removed from work_struct. The work_struct struct is huge, and this limits it's usefulness. On a 64-bit architecture it's nearly 100 bytes in size. This reduces that by half for the non-delayable type of event. Signed-Off-By: David Howells <dhowells@redhat.com>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-23[PATCH] list: use list_replace_init() instead of list_splice_init()Oleg Nesterov
list_splice_init(list, head) does unneeded job if it is known that list_empty(head) == 1. We can use list_replace_init() instead. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-09[NET] linkwatch: Handle jiffies wrap-aroundHerbert Xu
The test used in the linkwatch does not handle wrap-arounds correctly. Since the intention of the code is to eliminate bursts of messages we can afford to delay things up to a second. Using that fact we can easily handle wrap-arounds by making sure that we don't delay things by more than one second. This is based on diagnosis and a patch by Stefan Rompf. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Stefan Rompf <stefan@loplof.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[NET]: Convert RTNL to mutex.Stephen Hemminger
This patch turns the RTNL from a semaphore to a new 2.6.16 mutex and gets rid of some of the leftover legacy. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[NET] core: add RFC2863 operstateStefan Rompf
this patch adds a dormant flag to network devices, RFC2863 operstate derived from these flags and possibility for userspace interaction. It allows drivers to signal that a device is unusable for user traffic without disabling queueing (and therefore the possibility for protocol establishment traffic to flow) and a userspace supplicant (WPA, 802.1X) to mark a device unusable without changes to the driver. It is the result of our long discussion. However I must admit that it represents what Jamal and I agreed on with compromises towards Krzysztof, but Thomas and Krzysztof still disagree with some parts. Anyway I think it should be applied. Signed-off-by: Stefan Rompf <stefan@loplof.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-03[NET]: Disable queueing when carrier is lost.Tommy S. Christensen
Some network drivers call netif_stop_queue() when detecting loss of carrier. This leads to packets being queued up at the qdisc level for an unbound period of time. In order to prevent this effect, the core networking stack will now cease to queue packets for any device, that is operationally down (i.e. the queue is flushed and disabled). Signed-off-by: Tommy S. Christensen <tommy.christensen@tpack.net> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-04-16Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!