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* net: rename NETDEV_BONDING_DESLAVE to NETDEV_RELEASEAmerigo Wang2011-05-221-1/+1
| | | | | | | | | s/NETDEV_BONDING_DESLAVE/NETDEV_RELEASE/ as Andy suggested. Signed-off-by: WANG Cong <amwang@redhat.com> Cc: Andy Gospodarek <andy@greyhouse.net> Cc: Neil Horman <nhorman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netpoll: disable netpoll when enslave a deviceAmerigo Wang2011-05-221-0/+1
| | | | | | | | | | | | | | | | | | | V3: rename NETDEV_ENSLAVE to NETDEV_JOIN Currently we do nothing when we enslave a net device which is running netconsole. Neil pointed out that we may get weird results in such case, so let's disable netpoll on the device being enslaved. I think it is too harsh to prevent the device being ensalved if it is running netconsole. By the way, this patch also removes the NETDEV_GOING_DOWN from netconsole netdev notifier, because netpoll will check if the device is running or not and we don't handle NETDEV_PRE_UP neither. This patch is based on net-next-2.6. Signed-off-by: WANG Cong <amwang@redhat.com> Cc: Neil Horman <nhorman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Fix common misspellingsLucas De Marchi2011-03-311-1/+1
| | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* notifiers: __rcu annotationsArnd Bergmann2010-08-191-5/+5
| | | | | | | Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
* net: Fix NETDEV_NOTIFY_PEERS to not conflict with NETDEV_BONDING_DESLAVE.David S. Miller2010-05-311-1/+1
| | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* arp_notify: allow drivers to explicitly request a notification event.Ian Campbell2010-05-311-0/+1
| | | | | | | | | | | | | | | | | | | Currently such notifications are only generated when the device comes up or the address changes. However one use case for these notifications is to enable faster network recovery after a virtual machine migration (by causing switches to relearn their MAC tables). A migration appears to the network stack as a temporary loss of carrier and therefore does not trigger either of the current conditions. Rather than adding carrier up as a trigger (which can cause issues when interfaces a flapping) simply add an interface which the driver can use to explicitly trigger the notification. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Cc: Stephen Hemminger <shemminger@linux-foundation.org> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: David S. Miller <davem@davemloft.net> Cc: netdev@vger.kernel.org Cc: stable@kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
* notifier: change notifier_from_errno(0) to return NOTIFY_OKAkinobu Mita2010-05-271-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | This changes notifier_from_errno(0) to be NOTIFY_OK instead of NOTIFY_STOP_MASK | NOTIFY_OK. Currently, the notifiers which return encapsulated errno value have to do something like this: err = do_something(); // returns -errno if (err) return notifier_from_errno(err); else return NOTIFY_OK; This change makes the above code simple: err = do_something(); // returns -errno return return notifier_from_errno(err); Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* netpoll: add generic support for bridge and bonding devicesWANG Cong2010-05-061-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: WANG Cong <amwang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: rtnetlink: ignore NETDEV_PRE_TYPE_CHANGE in rtnetlink_event()Patrick McHardy2010-03-211-1/+4
| | | | | | | | | | | Ignore the new NETDEV_PRE_TYPE_CHANGE event in rtnetlink_event() since there have been no changes userspace needs to be notified of. Also add a comment to the netdev notifier event definitions to remind people to update the exclusion list when adding new event types. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: rename notifier defines for netdev type changeJiri Pirko2010-03-181-2/+2
| | | | | | | | Since generally there could be more netdevices changing type other than bonding, making this event type name "bonding-unrelated" Signed-off-by: Jiri Pirko <jpirko@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: NETDEV_UNREGISTER_PERNET -> NETDEV_UNREGISTER_BATCHEric W. Biederman2009-12-011-1/+1
| | | | | | | | | | | | | | | | | | | | | The motivation for an additional notifier in batched netdevice notification (rt_do_flush) only needs to be called once per batch not once per namespace. For further batching improvements I need a guarantee that the netdevices are unregistered in order allowing me to unregister an all of the network devices in a network namespace at the same time with the guarantee that the loopback device is really and truly unregistered last. Additionally it appears that we moved the route cache flush after the final synchronize_net, which seems wrong and there was no explanation. So I have restored the original location of the final synchronize_net. Cc: Octavian Purdila <opurdila@ixiacom.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: introduce NETDEV_UNREGISTER_PERNETOctavian Purdila2009-11-181-0/+1
| | | | | | | | | | | | | This new event is called once for each unique net namespace in batched unregister operations (with the argument set to a random device from that namespace) and once per device in non-batched unregister operations. It allows us to factorize some device unregister work such as clearing the routing cache. Signed-off-by: Octavian Purdila <opurdila@ixiacom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: introduce NETDEV_POST_INIT notifierJohannes Berg2009-10-051-0/+1
| | | | | | | | | | | | For various purposes including a wireless extensions bugfix, we need to hook into the netdev creation before before netdev_register_kobject(). This will also ease doing the dev type assignment that Marcel was working on for cfg80211 drivers w/o touching them all. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* bonding: remap muticast addresses without using dev_close() and dev_open()Moni Shoua2009-09-151-0/+2
| | | | | | | | | | | | | | | | | | | | This patch fixes commit e36b9d16c6a6d0f59803b3ef04ff3c22c3844c10. The approach there is to call dev_close()/dev_open() whenever the device type is changed in order to remap the device IP multicast addresses to HW multicast addresses. This approach suffers from 2 drawbacks: *. It assumes tha the device is UP when calling dev_close(), or otherwise dev_close() has no affect. It is worth to mention that initscripts (Redhat) and sysconfig (Suse) doesn't act the same in this matter. *. dev_close() has other side affects, like deleting entries from the routing table, which might be unnecessary. The fix here is to directly remap the IP multicast addresses to HW multicast addresses for a bonding device that changes its type, and nothing else. Reported-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Signed-off-by: Moni Shoua <monis@voltaire.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: introduce pre-up netdev notifierJohannes Berg2009-06-031-0/+1
| | | | | | | | | | | | NETDEV_UP is called after the device is set UP, but sometimes it is useful to be able to veto the device UP. Introduce a new NETDEV_PRE_UP notifier that can be used for exactly this. The first use case will be cfg80211 denying interfaces to be set UP if the device is known to be rfkill'ed. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
* kernel/cpu.c: create a CPU_STARTING cpu_chain notifierManfred Spraul2008-09-081-1/+9
| | | | | | | | | | | | | | | | | Right now, there is no notifier that is called on a new cpu, before the new cpu begins processing interrupts/softirqs. Various kernel function would need that notification, e.g. kvm works around by calling smp_call_function_single(), rcu polls cpu_online_map. The patch adds a CPU_STARTING notification. It also adds a helper function that sends the message to all cpu_chain handlers. Tested on x86-64. All other archs are untested. Especially on sparc, I'm not sure if I got it right. Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* workqueues: make get_online_cpus() useable for work->func()Oleg Nesterov2008-07-251-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | workqueue_cpu_callback(CPU_DEAD) flushes cwq->thread under cpu_maps_update_begin(). This means that the multithreaded workqueues can't use get_online_cpus() due to the possible deadlock, very bad and very old problem. Introduce the new state, CPU_POST_DEAD, which is called after cpu_hotplug_done() but before cpu_maps_update_done(). Change workqueue_cpu_callback() to use CPU_POST_DEAD instead of CPU_DEAD. This means that create/destroy functions can't rely on get_online_cpus() any longer and should take cpu_add_remove_lock instead. [akpm@linux-foundation.org: fix CONFIG_SMP=n] Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Gautham R Shenoy <ego@in.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Max Krasnyansky <maxk@qualcomm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Vegard Nossum <vegard.nossum@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* net/core: add NETDEV_BONDING_FAILOVER eventOr Gerlitz2008-06-171-0/+1
| | | | | | | | | | | | | | Add NETDEV_BONDING_FAILOVER event to be used in a successive patch by bonding to announce fail-over for the active-backup mode through the netdev events notifier chain mechanism. Such an event can be of use for the RDMA CM (communication manager) to let native RDMA ULPs (eg NFS-RDMA, iSER) always be aligned with the IP stack, in the sense that they use the same ports/links as the stack does. More usages can be done to allow monitoring tools based on netlink events being aware to bonding fail-over. Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com> Signed-off-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* ipc: re-enable msgmni automatic recomputing msgmni if set to negativeNadia Derbey2008-04-291-0/+4
| | | | | | | | | | | | | | | | | | The enhancement as asked for by Yasunori: if msgmni is set to a negative value, register it back into the ipcns notifier chain. A new interface has been added to the notification mechanism: notifier_chain_cond_register() registers a notifier block only if not already registered. With that new interface we avoid taking care of the states changes in procfs. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Mingming Cao <cmm@us.ibm.com> Cc: Pierre Peiffer <pierre.peiffer@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* VT notifier extension for accessibilityKarl Dahlke2008-04-281-0/+1
| | | | | | | | | | Some accessibility modules need to be able to catch the output on the console before the VT interpretation, and possibly swallow it. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Hibernation: Add PM_RESTORE_PREPARE and PM_POST_RESTORE notifiers (rev. 2)Alan Stern2008-02-011-0/+2
| | | | | | | | | | | Add PM_RESTORE_PREPARE and PM_POST_RESTORE notifiers to the PM core, to be used in analogy with the existing PM_HIBERNATION_PREPARE and PM_POST_HIBERNATION notifiers. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com>
* cpu-hotplug: replace per-subsystem mutexes with get_online_cpus()Gautham R Shenoy2008-01-251-3/+1
| | | | | | | | | This patch converts the known per-subsystem mutexes to get_online_cpus put_online_cpus. It also eliminates the CPU_LOCK_ACQUIRE and CPU_LOCK_RELEASE hotplug notification events. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Console events and accessibilitySamuel Thibault2007-10-191-0/+6
| | | | | | | | | | | | | Some external modules like Speakup need to monitor console output. This adds a VT notifier that such modules can use to get console output events: allocation, deallocation, writes, other updates (cursor position, switch, etc.) [akpm@linux-foundation.org: fix headers_check] Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Cc: Dmitry Torokhov <dtor@mail.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add kernel/notifier.cAlexey Dobriyan2007-10-191-0/+2
| | | | | | | | | | | | There is separate notifier header, but no separate notifier .c file. Extract notifier code out of kernel/sys.c which will remain for misc syscalls I hope. Merge kernel/die_notifier.c into kernel/notifier.c. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Console keyboard events and accessibilitySamuel Thibault2007-10-191-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some blind people use a kernel engine called Speakup which uses hardware synthesis to speak what gets displayed on the screen. They use the PC keyboard to control this engine (start/stop, accelerate, ...) and also need to get keyboard feedback (to make sure to know what they are typing, the caps lock status, etc.) Up to now, the way it was done was very ugly. Below is a patch to add a notifier list for permitting a far better implementation, see ChangeLog above for details. You may wonder why this can't be done at the input layer. The problem is that what people want to monitor is the console keyboard, i.e. all input keyboards that got attached to the console, and with the currently active keymap (i.e. keysyms, not only keycodes). This adds a keyboard notifier that such modules can use to get the keyboard events and possibly eat them, at several stages: - keycodes: even before translation into keysym. - unbound keycodes: when no keysym is bound. - unicode: when the keycode would get translated into a unicode character. - keysym: when the keycode would get translated into a keysym. - post_keysym: after the keysym got interpreted, so as to see the result (caps lock, etc.) This also provides access to k_handler so as to permit simulation of keypresses. [akpm@linux-foundation.org: various fixes] Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Dmitry Torokhov <dtor@mail.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [NET]: Allow netdev REGISTER/CHANGENAME events to failHerbert Xu2007-07-311-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds code to allow errors to be passed up from event handlers of NETDEV_REGISTER and NETDEV_CHANGENAME. It also adds the notifier_from_errno/notifier_to_errnor helpers to pass the errno value up to the notifier caller. If an error is detected when a device is registered, it causes that operation to fail. A NETDEV_UNREGISTER will be sent to all event handlers. Similarly if NETDEV_CHANGENAME fails the original name is restored and a new NETDEV_CHANGENAME event is sent. As such all event handlers must be idempotent with respect to these events. When an event handler is registered NETDEV_REGISTER events are sent for all devices currently registered. Should any of them fail, we will send NETDEV_GOING_DOWN/NETDEV_DOWN/NETDEV_UNREGISTER events to that handler for the devices which have already been registered with it. The handler registration itself will fail. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
* PM: introduce hibernation and suspend notifiersRafael J. Wysocki2007-07-191-0/+6
| | | | | | | | | | | | | | | Make it possible to register hibernation and suspend notifiers, so that subsystems can perform hibernation-related or suspend-related operations that should not be carried out by device drivers' .suspend() and .resume() routines. [akpm@linux-foundation.org: build fixes] [akpm@linux-foundation.org: cleanups] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Nigel Cunningham <nigel@nigel.suspend2.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* HOTPLUG: Add CPU_DYING notifierAvi Kivity2007-07-161-0/+3
| | | | | | | | | | | | KVM wants a notification when a cpu is about to die, so it can disable hardware extensions, but at a time when user processes cannot be scheduled on the cpu, so it doesn't try to use virtualization extensions after they have been disabled. This adds a CPU_DYING notification. The notification is called in atomic context on the doomed cpu. Signed-off-by: Avi Kivity <avi@qumranet.com>
* Add suspend-related notifications for CPU hotplugRafael J. Wysocki2007-05-091-0/+12
| | | | | | | | | | | | | | | | | | | | | Since nonboot CPUs are now disabled after tasks and devices have been frozen and the CPU hotplug infrastructure is used for this purpose, we need special CPU hotplug notifications that will help the CPU-hotplug-aware subsystems distinguish normal CPU hotplug events from CPU hotplug events related to a system-wide suspend or resume operation in progress. This patch introduces such notifications and causes them to be used during suspend and resume transitions. It also changes all of the CPU-hotplug-aware subsystems to take these notifications into consideration (for now they are handled in the same way as the corresponding "normal" ones). [oleg@tv-sign.ru: cleanups] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Define and use new events,CPU_LOCK_ACQUIRE and CPU_LOCK_RELEASEGautham R Shenoy2007-05-091-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is an attempt to provide an alternate mechanism for postponing a hotplug event instead of using a global mechanism like lock_cpu_hotplug. The proposal is to add two new events namely CPU_LOCK_ACQUIRE and CPU_LOCK_RELEASE. The notification for these two events would be sent out before and after a cpu_hotplug event respectively. During the CPU_LOCK_ACQUIRE event, a cpu-hotplug-aware subsystem is supposed to acquire any per-subsystem hotcpu mutex ( Eg. workqueue_mutex in kernel/workqueue.c ). During the CPU_LOCK_RELEASE release event the cpu-hotplug-aware subsystem is supposed to release the per-subsystem hotcpu mutex. The reasons for defining new events as opposed to reusing the existing events like CPU_UP_PREPARE/CPU_UP_FAILED/CPU_ONLINE for locking/unlocking of per-subsystem hotcpu mutexes are as follow: - CPU_LOCK_ACQUIRE: All hotcpu mutexes are taken before subsystems start handling pre-hotplug events like CPU_UP_PREPARE/CPU_DOWN_PREPARE etc, thus ensuring a clean handling of these events. - CPU_LOCK_RELEASE: The hotcpu mutexes will be released only after all subsystems have handled post-hotplug events like CPU_DOWN_FAILED, CPU_DEAD,CPU_ONLINE etc thereby ensuring that there are no subsequent clashes amongst the interdependent subsystems after a cpu hotplugs. This patch also uses __raw_notifier_call chain in _cpu_up to take care of the dependency between the two consequetive calls to raw_notifier_call_chain. [akpm@linux-foundation.org: fix a bug] Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Extend notifier_call_chain to count nr_calls madeGautham R Shenoy2007-05-091-22/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since 2.6.18-something, the community has been bugged by the problem to provide a clean and a stable mechanism to postpone a cpu-hotplug event as lock_cpu_hotplug was badly broken. This is another proposal towards solving that problem. This one is along the lines of the solution provided in kernel/workqueue.c Instead of having a global mechanism like lock_cpu_hotplug, we allow the subsytems to define their own per-subsystem hot cpu mutexes. These would be taken(released) where ever we are currently calling lock_cpu_hotplug(unlock_cpu_hotplug). Also, in the per-subsystem hotcpu callback function,we take this mutex before we handle any pre-cpu-hotplug events and release it once we finish handling the post-cpu-hotplug events. A standard means for doing this has been provided in [PATCH 2/4] and demonstrated in [PATCH 3/4]. The ordering of these per-subsystem mutexes might still prove to be a problem, but hopefully lockdep should help us get out of that muddle. The patch set to be applied against linux-2.6.19-rc5 is as follows: [PATCH 1/4] : Extend notifier_call_chain with an option to specify the number of notifications to be sent and also count the number of notifications actually sent. [PATCH 2/4] : Define events CPU_LOCK_ACQUIRE and CPU_LOCK_RELEASE and send out notifications for these in _cpu_up and _cpu_down. This would help us standardise the acquire and release of the subsystem locks in the hotcpu callback functions of these subsystems. [PATCH 3/4] : Eliminate lock_cpu_hotplug from kernel/sched.c. [PATCH 4/4] : In workqueue_cpu_callback function, acquire(release) the workqueue_mutex while handling CPU_LOCK_ACQUIRE(CPU_LOCK_RELEASE). If the per-subsystem-locking approach survives the test of time, we can expect a slow phasing out of lock_cpu_hotplug, which has not yet been eliminated in these patches :) This patch: Provide notifier_call_chain with an option to call only a specified number of notifiers and also record the number of call to notifiers made. The need for this enhancement was identified in the post entitled "Slab - Eliminate lock_cpu_hotplug from slab" (http://lkml.org/lkml/2006/10/28/92) by Ravikiran G Thirumalai and Andrew Morton. This patch adds two additional parameters to notifier_call_chain API namely - int nr_to_calls : Number of notifier_functions to be called. The don't care value is -1. - unsigned int *nr_calls : Records the total number of notifier_funtions called by notifier_call_chain. The don't care value is NULL. [michal.k.k.piotrowski@gmail.com: build fix] Credit: Andrew Morton <akpm@osdl.org> Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] Add SRCU-based notifier chainsAlan Stern2006-10-041-5/+38
| | | | | | | | | | | | | | | | | | | | | | | This patch (as751) adds a new type of notifier chain, based on the SRCU (Sleepable Read-Copy Update) primitives recently added to the kernel. An SRCU notifier chain is much like a blocking notifier chain, in that it must be called in process context and its callout routines are allowed to sleep. The difference is that the chain's links are protected by the SRCU mechanism rather than by an rw-semaphore, so calling the chain has extremely low overhead: no memory barriers and no cache-line bouncing. On the other hand, unregistering from the chain is expensive and the chain head requires special runtime initialization (plus cleanup if it is to be deallocated). SRCU notifiers are appropriate for notifiers that will be called very frequently and for which unregistration occurs very seldom. The proposed "task notifier" scheme qualifies, as may some of the network notifiers. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Paul E. McKenney <paulmck@us.ibm.com> Acked-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] lockdep: locking init debugging improvementIngo Molnar2006-07-031-1/+1
| | | | | | | | | | | | Locking init improvement: - introduce and use __SPIN_LOCK_UNLOCKED for array initializations, to pass in the name string of locks, used by debugging Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Notifier chain update: API changesAlan Stern2006-03-271-7/+89
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel's implementation of notifier chains is unsafe. There is no protection against entries being added to or removed from a chain while the chain is in use. The issues were discussed in this thread: http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2 We noticed that notifier chains in the kernel fall into two basic usage classes: "Blocking" chains are always called from a process context and the callout routines are allowed to sleep; "Atomic" chains can be called from an atomic context and the callout routines are not allowed to sleep. We decided to codify this distinction and make it part of the API. Therefore this set of patches introduces three new, parallel APIs: one for blocking notifiers, one for atomic notifiers, and one for "raw" notifiers (which is really just the old API under a new name). New kinds of data structures are used for the heads of the chains, and new routines are defined for registration, unregistration, and calling a chain. The three APIs are explained in include/linux/notifier.h and their implementation is in kernel/sys.c. With atomic and blocking chains, the implementation guarantees that the chain links will not be corrupted and that chain callers will not get messed up by entries being added or removed. For raw chains the implementation provides no guarantees at all; users of this API must provide their own protections. (The idea was that situations may come up where the assumptions of the atomic and blocking APIs are not appropriate, so it should be possible for users to handle these things in their own way.) There are some limitations, which should not be too hard to live with. For atomic/blocking chains, registration and unregistration must always be done in a process context since the chain is protected by a mutex/rwsem. Also, a callout routine for a non-raw chain must not try to register or unregister entries on its own chain. (This did happen in a couple of places and the code had to be changed to avoid it.) Since atomic chains may be called from within an NMI handler, they cannot use spinlocks for synchronization. Instead we use RCU. The overhead falls almost entirely in the unregister routine, which is okay since unregistration is much less frequent that calling a chain. Here is the list of chains that we adjusted and their classifications. None of them use the raw API, so for the moment it is only a placeholder. ATOMIC CHAINS ------------- arch/i386/kernel/traps.c: i386die_chain arch/ia64/kernel/traps.c: ia64die_chain arch/powerpc/kernel/traps.c: powerpc_die_chain arch/sparc64/kernel/traps.c: sparc64die_chain arch/x86_64/kernel/traps.c: die_chain drivers/char/ipmi/ipmi_si_intf.c: xaction_notifier_list kernel/panic.c: panic_notifier_list kernel/profile.c: task_free_notifier net/bluetooth/hci_core.c: hci_notifier net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_chain net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_expect_chain net/ipv6/addrconf.c: inet6addr_chain net/netfilter/nf_conntrack_core.c: nf_conntrack_chain net/netfilter/nf_conntrack_core.c: nf_conntrack_expect_chain net/netlink/af_netlink.c: netlink_chain BLOCKING CHAINS --------------- arch/powerpc/platforms/pseries/reconfig.c: pSeries_reconfig_chain arch/s390/kernel/process.c: idle_chain arch/x86_64/kernel/process.c idle_notifier drivers/base/memory.c: memory_chain drivers/cpufreq/cpufreq.c cpufreq_policy_notifier_list drivers/cpufreq/cpufreq.c cpufreq_transition_notifier_list drivers/macintosh/adb.c: adb_client_list drivers/macintosh/via-pmu.c sleep_notifier_list drivers/macintosh/via-pmu68k.c sleep_notifier_list drivers/macintosh/windfarm_core.c wf_client_list drivers/usb/core/notify.c usb_notifier_list drivers/video/fbmem.c fb_notifier_list kernel/cpu.c cpu_chain kernel/module.c module_notify_list kernel/profile.c munmap_notifier kernel/profile.c task_exit_notifier kernel/sys.c reboot_notifier_list net/core/dev.c netdev_chain net/decnet/dn_dev.c: dnaddr_chain net/ipv4/devinet.c: inetaddr_chain It's possible that some of these classifications are wrong. If they are, please let us know or submit a patch to fix them. Note that any chain that gets called very frequently should be atomic, because the rwsem read-locking used for blocking chains is very likely to incur cache misses on SMP systems. (However, if the chain's callout routines may sleep then the chain cannot be atomic.) The patch set was written by Alan Stern and Chandra Seetharaman, incorporating material written by Keith Owens and suggestions from Paul McKenney and Andrew Morton. [jes@sgi.com: restructure the notifier chain initialization macros] Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Jes Sorensen <jes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [BRIDGE]: features change notificationStephen Hemminger2005-05-291-0/+1
| | | | | | | | | Resend of earlier patch (no changes) from Catalin used to provide device feature change notification. Signed-off-by: Catalin BOIE <catab at umbrella.ro> Acked-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* Linux-2.6.12-rc2Linus Torvalds2005-04-161-0/+75
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!
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