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* workqueue: don't migrate pending works from the dead CPUOleg Nesterov2007-05-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently CPU_DEAD uses kthread_stop() to stop cwq->thread and then transfers cwq->worklist to another CPU. However, it is very unlikely that worker_thread() will notice kthread_should_stop() before flushing cwq->worklist. It is only possible if worker_thread() was preempted after run_workqueue(cwq), a new work_struct was added, and CPU_DEAD happened before cwq->thread has a chance to run. This means that take_over_work() mostly adds unneeded complications. Note also that kthread_stop() is not good per se, wake_up_process() may confuse work->func() if it sleeps waiting for some event. Remove take_over_work() and migrate_sequence complications. CPU_DEAD sets the cwq->should_stop flag (introduced by this patch) and waits for cwq->thread to flush cwq->worklist and exit. Because the dead CPU is not on cpu_online_map, no more works can be added to that cwq. cpu_populated_map was introduced to optimize for_each_possible_cpu(), it is not strictly needed, and it is more a documentation in fact. Saves 418 bytes. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com> Cc: Gautham shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* workqueue: don't clear cwq->thread until it exitsOleg Nesterov2007-05-09
| | | | | | | | | | | | | | | | | | Pointed out by Srivatsa Vaddagiri. cleanup_workqueue_thread() sets cwq->thread = NULL and does kthread_stop(). This breaks the "if (cwq->thread == current)" logic in flush_cpu_workqueue() and leads to deadlock. Kill the thead first, then clear cwq->thread. workqueue_mutex protects us from create_workqueue_thread() so we don't need cwq->lock. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com> Cc: Gautham shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* workqueue: fix flush_workqueue() vs CPU_DEAD raceOleg Nesterov2007-05-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many thanks to Srivatsa Vaddagiri for the helpful discussion and for spotting the bug in my previous attempt. work->func() (and thus flush_workqueue()) must not use workqueue_mutex, this leads to deadlock when CPU_DEAD does kthread_stop(). However without this mutex held we can't detect CPU_DEAD in progress, which can move pending works to another CPU while the dead one is not on cpu_online_map. Change flush_workqueue() to use for_each_possible_cpu(). This means that flush_cpu_workqueue() may hit CPU which is already dead. However in that case !list_empty(&cwq->worklist) || cwq->current_work != NULL means that CPU_DEAD in progress, it will do kthread_stop() + take_over_work() so we can proceed and insert a barrier. We hold cwq->lock, so we are safe. Also, add migrate_sequence incremented by take_over_work() under cwq->lock. If take_over_work() happened before we checked this CPU, we should see the new value after spin_unlock(). Further possible changes: remove CPU_DEAD handling (along with take_over_work, migrate_sequence) from workqueue.c. CPU_DEAD just sets cwq->please_exit_after_flush flag. CPU_UP_PREPARE->create_workqueue_thread() clears this flag, and creates the new thread if cwq->thread == NULL. This way the workqueue/cpu-hotplug interaction is almost zero, workqueue_mutex just protects "workqueues" list, CPU_LOCK_ACQUIRE/CPU_LOCK_RELEASE go away. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com> Cc: Gautham shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* workqueue: fix freezeable workqueues implementationOleg Nesterov2007-05-09
| | | | | | | | | | | | Currently ->freezeable is per-cpu, this is wrong. CPU_UP_PREPARE creates cwq->thread which is not freezeable. Move ->freezeable to workqueue_struct. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com> Cc: Gautham shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* slab: use CPU_LOCK_[ACQUIRE|RELEASE]Heiko Carstens2007-05-09
| | | | | | | | | | | | | Looks like this was forgotten when CPU_LOCK_[ACQUIRE|RELEASE] was introduced. Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Gautham Shenoy <ego@in.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* call cpu_chain with CPU_DOWN_FAILED if CPU_DOWN_PREPARE failedHeiko Carstens2007-05-09
| | | | | | | | | | | | | | This makes cpu hotplug symmetrical: if CPU_UP_PREPARE fails we get CPU_UP_CANCELED, so we can undo what ever happened on PREPARE. The same should happen for CPU_DOWN_PREPARE. [akpm@linux-foundation.org: fix for reduce-size-of-task_struct-on-64-bit-machines] Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Gautham Shenoy <ego@in.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Eliminate lock_cpu_hotplug in kernel/schedcGautham R Shenoy2007-05-09
| | | | | | | | | | | | | | Eliminate lock_cpu_hotplug from kernel/sched.c and use sched_hotcpu_mutex instead to postpone a hotplug event. In the migration_call hotcpu callback function, take sched_hotcpu_mutex while handling the event CPU_LOCK_ACQUIRE and release it while handling CPU_LOCK_RELEASE event. [akpm@linux-foundation.org: fix deadlock] 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>
* Define and use new events,CPU_LOCK_ACQUIRE and CPU_LOCK_RELEASEGautham R Shenoy2007-05-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Shenoy2007-05-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* relay: use plain timer instead of delayed workTom Zanussi2007-05-09
| | | | | | | | | | | relay doesn't need to use schedule_delayed_work() for waking readers when a simple timer will do. Signed-off-by: Tom Zanussi <zanussi@comcast.net> Cc: Satyam Sharma <satyam.sharma@gmail.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* phy: use flush_work_keventd()Andrew Morton2007-05-09
| | | | | | | | | | | | (akpm: bypassed maintainers, sorry. There are other patches which depend on this) Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: David Howells <dhowells@redhat.com> Cc: Jeff Garzik <jeff@garzik.org> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* libata: use flush_work()Andrew Morton2007-05-09
| | | | | | | | | | | | | (akpm: bypassed maintainers, sorry. There are other patches which depend on this) Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: David Howells <dhowells@redhat.com> Cc: Jeff Garzik <jeff@garzik.org> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Tejun Heo <htejun@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* e1000: use flush_work_keventd()Andrew Morton2007-05-09
| | | | | | | | | | | | | | | | | Switch e1000 over to flush_work_keventd(). This probably fixes a netdev-close versus linkwatch rtnl_lock() deadlock which nobody knew about. (akpm: bypassed maintainers, sorry. There are other patches which depend on this) Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: David Howells <dhowells@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jeff Garzik <jeff@garzik.org> Acked-by: Auke Kok <auke-jan.h.kok@intel.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tg3: use flush_work_keventd()Andrew Morton2007-05-09
| | | | | | | | | | | | | | | | | Convert tg3 over to flush_work_keventd(). Remove nasty now-unneeded deadlock avoidance logic. (akpm: bypassed maintainers, sorry. There are other patches which depend on this) Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: David Howells <dhowells@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Michael Chan <mchan@broadcom.com> Cc: Jeff Garzik <jeff@garzik.org> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kblockd: use flush_workAndrew Morton2007-05-09
| | | | | | | | | | | | | | | | Switch the kblockd flushing from a global flush to a more specific flush_work(). (akpm: bypassed maintainers, sorry. There are other patches which depend on this) Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: David Howells <dhowells@redhat.com> Cc: Jens Axboe <axboe@suse.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* aio: use flush_work()Andrew Morton2007-05-09
| | | | | | | | | | | | Migrate AIO over to use flush_work(). Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: David Howells <dhowells@redhat.com> Cc: Zach Brown <zach.brown@oracle.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* flush_cpu_workqueue: don't flush an empty ->worklistOleg Nesterov2007-05-09
| | | | | | | | | | | | | | Now when we have ->current_work we can avoid adding a barrier and waiting for its completition when cwq's queue is empty. Note: this change is also useful if we change flush_workqueue() to also check the dead CPUs. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Gautham Shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* flush_workqueue(): use preempt_disable to hold off cpu hotplugAndrew Morton2007-05-09
| | | | | | | | Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Gautham Shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* implement flush_work()Oleg Nesterov2007-05-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A basic problem with flush_scheduled_work() is that it blocks behind _all_ presently-queued works, rather than just the work whcih the caller wants to flush. If the caller holds some lock, and if one of the queued work happens to want that lock as well then accidental deadlocks can occur. One example of this is the phy layer: it wants to flush work while holding rtnl_lock(). But if a linkwatch event happens to be queued, the phy code will deadlock because the linkwatch callback function takes rtnl_lock. So we implement a new function which will flush a *single* work - just the one which the caller wants to free up. Thus we avoid the accidental deadlocks which can arise from unrelated subsystems' callbacks taking shared locks. flush_work() non-blockingly dequeues the work_struct which we want to kill, then it waits for its handler to complete on all CPUs. Add ->current_work to the "struct cpu_workqueue_struct", it points to currently running "struct work_struct". When flush_work(work) detects ->current_work == work, it inserts a barrier at the _head_ of ->worklist (and thus right _after_ that work) and waits for completition. This means that the next work fired on that CPU will be this barrier, or another barrier queued by concurrent flush_work(), so the caller of flush_work() will be woken before any "regular" work has a chance to run. When wait_on_work() unlocks workqueue_mutex (or whatever we choose to protect against CPU hotplug), CPU may go away. But in that case take_over_work() will move a barrier we queued to another CPU, it will be fired sometime, and wait_on_work() will be woken. Actually, we are doing cleanup_workqueue_thread()->kthread_stop() before take_over_work(), so cwq->thread should complete its ->worklist (and thus the barrier), because currently we don't check kthread_should_stop() in run_workqueue(). But even if we did, everything should be ok. [akpm@osdl.org: cleanup] [akpm@osdl.org: add flush_work_keventd() wrapper] 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>
* reimplement flush_workqueue()Oleg Nesterov2007-05-09
| | | | | | | | | | | | | | | Remove ->remove_sequence, ->insert_sequence, and ->work_done from struct cpu_workqueue_struct. To implement flush_workqueue() we can queue a barrier work on each CPU and wait for its completition. The barrier is queued under workqueue_mutex to ensure that per cpu wq->cpu_wq is alive, we drop this mutex before going to sleep. If CPU goes down while we are waiting for completition, take_over_work() will move the barrier on another CPU, and the handler will wake up us eventually. 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>
* schedule_on_each_cpu(): use preempt_disable()Andrew Morton2007-05-09
| | | | | | | | | We take workqueue_mutex in there to keep CPU hotplug away. But preempt_disable() will suffice for that. Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* atmel_spi: remove unnecessary (and wrong) #ifdefsHaavard Skinnemoen2007-05-09
| | | | | | | | | | | | | | Now that the cpu_is_xxx() macros are available both on AVR32 and AT91, we can remove a couple of #ifdefs from this driver. One of them is actually wrong -- new_1 should be set on AVR32 but isn't. This causes the bus clock to run at twice the speed it is configured to. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: David Brownell <david-b@pacbell.net> Acked-by: Andrew Victor <andrew@sanpeople.com> Cc: Nicolas Ferre <nicolas.ferre@rfo.atmel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Use common cpu_is_xxx() macros on AT91 and AVR32Haavard Skinnemoen2007-05-09
| | | | | | | | | | | | | | | | | | Several drivers shared between AT91 and AVR32 chips use cpu_is_xxx() to handle CPU-specific differences. Currently, such code needs to be inside #ifdef CONFIG_ARCH_AT91 because the macros don't exist on AVR32. By defining the same macros on both AT91 and AVR32, these #ifdefs can be eliminated. Since the macros will evaluate to a constant value for CPUs that aren't supported by the current architecture, any code that is only needed on AT91 will be optimized away on AVR32 and vice versa. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: David Brownell <david-b@pacbell.net> Acked-by: Andrew Victor <andrew@sanpeople.com> Cc: Nicolas Ferre <nicolas.ferre@rfo.atmel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* AFS: implement basic file write supportDavid Howells2007-05-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement support for writing to regular AFS files, including: (1) write (2) truncate (3) fsync, fdatasync (4) chmod, chown, chgrp, utime. AFS writeback attempts to batch writes into as chunks as large as it can manage up to the point that it writes back 65535 pages in one chunk or it meets a locked page. Furthermore, if a page has been written to using a particular key, then should another write to that page use some other key, the first write will be flushed before the second is allowed to take place. If the first write fails due to a security error, then the page will be scrapped and reread before the second write takes place. If a page is dirty and the callback on it is broken by the server, then the dirty data is not discarded (same behaviour as NFS). Shared-writable mappings are not supported by this patch. [akpm@linux-foundation.org: fix a bunch of warnings] Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* AFS: AFS fixupsDavid Howells2007-05-09
| | | | | | | | | | | | | | | | | | | | | Make some miscellaneous changes to the AFS filesystem: (1) Assert RCU barriers on module exit to make sure RCU has finished with callbacks in this module. (2) Correctly handle the AFS server returning a zero-length read. (3) Split out data zapping calls into one function (afs_zap_data). (4) Rename some afs_file_*() functions to afs_*() where they apply to non-regular files too. (5) Be consistent about the presentation of volume ID:vnode ID in debugging output. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* AFS: export a couple of core functions for AFS write supportDavid Howells2007-05-09
| | | | | | | | | | | Export a couple of core functions for AFS write support to use: find_get_pages_contig() find_get_pages_tag() Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix printk format warnings in timer_list.cDavid Miller2007-05-09
| | | | | | | | | | | | | u64 and s64 are not necessarily 'long long' on some 64-bit platforms, so explicit the type to kill the compiler warnings. Also consistently use '%Lu' which is unsigned. Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel-doc: small kernel-doc optimizationBorislav Petkov2007-05-09
| | | | | | | | | | Get the kernel version string only once from the environment, thus slightly speeding up kernel-doc. Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* doc: what a patch series isRandy Dunlap2007-05-09
| | | | | | | | | | It seems that we need to clarify that a patch series is a series of related patches rather than "here are some of my patches as multiple (numbered) emails." Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: use path_walk in do_path_lookupJosef 'Jeff' Sipek2007-05-09
| | | | | | | | | | Since path_walk sets the total_link_count to 0 and calls link_path_walk, we can just call path_walk directly. Signed-off-by: Josef 'Jeff' Sipek <jsipek@cs.sunysb.edu> Acked-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: fix indentation in do_path_lookupJosef 'Jeff' Sipek2007-05-09
| | | | | | | Signed-off-by: Josef 'Jeff' Sipek <jsipek@cs.sunysb.edu> Acked-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* clocksource: spelling error in watchdog codeDaniel Walker2007-05-09
| | | | | | | | There's more that need fixing, and fix my own subject spelling error too. Signed-off-by: Daniel Walker <dwalker@mvista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mutex_lock_interruptible(): add __must_checkAndrew Morton2007-05-09
| | | | | | | | | | It's not sane to use mutex_lock_interruptible() and to then ignore the result. Ditto down_interruptible(), but I'm lazy. Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty_set_ldisc() receive_room fixPaul Fulghum2007-05-09
| | | | | | | | | | | | | | | | | | | | | | | | | | Fix tty_set_ldisc in tty_io.c so that tty->receive_room is only cleared if actually changing line disciplines. Without this fix a problem occurs when requesting the line discipline to change to the same line discipline. In this case tty->receive_room is cleared but ldisc->open() is not called to set tty->receive_room back to a sane value. The result is that tty->receive_room is stuck at 0 preventing the tty flip buffer from passing receive data to the line discipline. For example: a switch from N_TTY to N_TTY followed by a select() call for read input results in data never being received because tty->receive_room is stuck at zero. A switch from N_TTY to N_TTY followed by a read() call works because the read() call itself sets tty->receive_room correctly (but select does not). Previously (< 2.6.18) this was not a problem because the tty flip buffer pushed data to the line discipline without regard for tty->receive room. Signed-off-by: Paul Fulghum <paulkf@microgate.com> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Move sig_kernel_* et al macros to linux/signal.hRoland McGrath2007-05-09
| | | | | | | | | | | This patch moves the sig_kernel_* and related macros from kernel/signal.c to linux/signal.h, and cleans them up slightly. I need the sig_kernel_* macros for default signal behavior in the utrace code, and want to avoid duplication or overhead to share the knowledge. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* nbd: check the return value of sysfs_create_fileWANG Cong2007-05-09
| | | | | | | | [akpm@linux-foundation.org: fix it] Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Cc: Paul Clements <paul.clements@steeleye.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pasemi: hardware rng driverOlof Johansson2007-05-09
| | | | | | | | | | | | | Driver for the on-chip hardware random number generator on PA Semi PA6T-1682M. Signed-off-by: Egor Martovetsky <egor@pasemi.com> Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Michael Buesch <mb@bu3sch.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Kumar Gala <galak@gate.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add info about whitespace to SubmitChecklistRoland Dreier2007-05-09
| | | | | | Signed-off-by: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pretend cpuset has some form of hugetlb page reservationKen Chen2007-05-09
| | | | | | | | | | | | | | | | | | | | | | | When cpuset is configured, it breaks the strict hugetlb page reservation as the accounting is done on a global variable. Such reservation is completely rubbish in the presence of cpuset because the reservation is not checked against page availability for the current cpuset. Application can still potentially OOM'ed by kernel with lack of free htlb page in cpuset that the task is in. Attempt to enforce strict accounting with cpuset is almost impossible (or too ugly) because cpuset is too fluid that task or memory node can be dynamically moved between cpusets. The change of semantics for shared hugetlb mapping with cpuset is undesirable. However, in order to preserve some of the semantics, we fall back to check against current free page availability as a best attempt and hopefully to minimize the impact of changing semantics that cpuset has on hugetlb. Signed-off-by: Ken Chen <kenchen@google.com> Cc: Paul Jackson <pj@sgi.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* use simple_read_from_buffer in kernel/Akinobu Mita2007-05-09
| | | | | | | | | | | Cleanup using simple_read_from_buffer() for /dev/cpuset/tasks and /proc/config.gz. Cc: Paul Jackson <pj@sgi.com> Cc: Randy Dunlap <rdunlap@xenotime.net> 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>
* use simple_read_from_buffer() in fs/Akinobu Mita2007-05-09
| | | | | | | | | | Cleanup using simple_read_from_buffer() in binfmt_misc, configfs, and sysfs. Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Joel Becker <joel.becker@oracle.com> 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>
* cm4000_cs: use bitrevAkinobu Mita2007-05-09
| | | | | | | | | | Cleanup using bitrev8 in cm4000_cs driver. Cc: Harald Welte <laforge@gnumonks.org> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cm4000_cs: fix error pathsAkinobu Mita2007-05-09
| | | | | | | | | | | This patch fixes error paths in module_init and probe functions in cm4000_cs and cm4040_cs drivers. Cc: Harald Welte <laforge@gnumonks.org> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mca: add integrated device bus matchingJames Bottomley2007-05-09
| | | | | | | | | | | | The MCA bus has a few "integrated" functions, which are effectively virtual slots on the bus. The problem is that these special functions don't have dedicated pos IDs, so we have to manufacture ids for them outside the pos space ... and these ids can't be matched by the standard matching function, so add a special registration that requests a list of pos ids or a particular integrated function. Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mca: fix bus matchingJames Bottomley2007-05-09
| | | | | | | | | | | There's a bug in the MCA bus matching algorithm in that it promotes from signed short to int before comparing with the actual id and does sign extension on anything > 0x7fff (which means that pos ids > 0x7fff never get correctly matched). Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Always ask the hardware to obtain hardware processor id - ia64Fernando Luis Vazquez Cao2007-05-09
| | | | | | | | | | | | | Always ask the hardware to determine the hardware processor id in both UP and SMP kernels. Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Andi Kleen <ak@suse.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Use the APIC to determine the hardware processor id - x86_64Fernando Luis Vazquez Cao2007-05-09
| | | | | | | | | | | | | | | | | | | | | | | hard_smp_processor_id used to be just a macro that hard-coded hard_smp_processor_id to 0 in the non SMP case. When booting non SMP kernels on hardware where the boot ioapic id is not 0 this turns out to be a problem. This is happens frequently in the case of kdump and once in a great while in the case of real hardware. Use the APIC to determine the hardware processor id in both UP and SMP kernels to fix this issue. Notice that hard_smp_processor_id is only used by SMP code or by code that works with apics so we do not need to handle the case when apics are not present and hard_smp_processor_id should never be called there. Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Cc: "Luck, Tony" <tony.luck@intel.com> Acked-by: Andi Kleen <ak@suse.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Use the APIC to determine the hardware processor id - i386Fernando Luis Vazquez Cao2007-05-09
| | | | | | | | | | | | | | | | | | | | | | | hard_smp_processor_id used to be just a macro that hard-coded hard_smp_processor_id to 0 in the non SMP case. When booting non SMP kernels on hardware where the boot ioapic id is not 0 this turns out to be a problem. This is happens frequently in the case of kdump and once in a great while in the case of real hardware. Use the APIC to determine the hardware processor id in both UP and SMP kernels to fix this issue. Notice that hard_smp_processor_id is only used by SMP code or by code that works with apics so we do not need to handle the case when apics are not present and hard_smp_processor_id should never be called there. Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Cc: "Luck, Tony" <tony.luck@intel.com> Acked-by: Andi Kleen <ak@suse.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Remove hardcoding of hard_smp_processor_id on UP systemsFernando Luis Vazquez Cao2007-05-09
| | | | | | | | | | | | | | | | | | | | With the advent of kdump, the assumption that the boot CPU when booting an UP kernel is always the CPU with a particular hardware ID (often 0) (usually referred to as BSP on some architectures) is not valid anymore. The reason being that the dump capture kernel boots on the crashed CPU (the CPU that invoked crash_kexec), which may be or may not be that particular CPU. Move definition of hard_smp_processor_id for the UP case to architecture-specific code ("asm/smp.h") where it belongs, so that each architecture can provide its own implementation. Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Cc: "Luck, Tony" <tony.luck@intel.com> Acked-by: Andi Kleen <ak@suse.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Display all possible partitions when the root filesystem failed to mountDave Gilbert2007-05-09
| | | | | | | | | | | | | | | | | | | | | | | Display all possible partitions when the root filesystem is not mounted. This helps to track spell'o's and missing drivers. Updated to work with newer kernels. Example output: VFS: Cannot open root device "foobar" or unknown-block(0,0) Please append a correct "root=" boot option; here are the available partitions: 0800 8388608 sda driver: sd 0801 192748 sda1 0802 8193150 sda2 0810 4194304 sdb driver: sd Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) [akpm@linux-foundation.org: cleanups, fix printk warnings] Signed-off-by: Jan Engelhardt <jengelh@gmx.de> Cc: Dave Gilbert <linux@treblig.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>