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2011-12-21lockdep/waitqueues: Add better annotationPeter Zijlstra
-> #2 (&tty->write_wait){-.-...}: is a lot more informative than: -> #2 (key#19){-.....}: Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-8zpopbny51023rdb0qq67eye@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-10-31kernel: Map most files to use export.h instead of module.hPaul Gortmaker
The changed files were only including linux/module.h for the EXPORT_SYMBOL infrastructure, and nothing else. Revector them onto the isolated export header for faster compile times. Nothing to see here but a whole lot of instances of: -#include <linux/module.h> +#include <linux/export.h> This commit is only changing the kernel dir; next targets will probably be mm, fs, the arch dirs, etc. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2010-10-26docbook: add more wait/wake/completion to device-drivers docbookRandy Dunlap
Add more wait, wake, and completion interfaces to the device-drivers docbook. Fix kernel-doc notation in the added files. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-10locking, sched: Give waitqueue spinlocks their own lockdep classesPeter Zijlstra
Give waitqueue spinlocks their own lockdep classes when they are initialised from init_waitqueue_head(). This means that struct wait_queue::func functions can operate other waitqueues. This is used by CacheFiles to catch the page from a backing fs being unlocked and to wake up another thread to take a copy of it. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Takashi Iwai <tiwai@suse.de> Cc: linux-cachefs@redhat.com Cc: torvalds@osdl.org Cc: akpm@linux-foundation.org LKML-Reference: <20090810113305.17284.81508.stgit@warthog.procyon.org.uk> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14wait: don't use __wake_up_common()Johannes Weiner
'777c6c5 wait: prevent exclusive waiter starvation' made __wake_up_common() global to be used from abort_exclusive_wait(). It was needed to do a wake-up with the waitqueue lock held while passing down a key to the wake-up function. Since '4ede816 epoll keyed wakeups: add __wake_up_locked_key() and __wake_up_sync_key()' there is an appropriate wrapper for this case: __wake_up_locked_key(). Use it here and make __wake_up_common() private to the scheduler again. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1239720785-19661-1-git-send-email-hannes@cmpxchg.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-05wait: prevent exclusive waiter starvationJohannes Weiner
With exclusive waiters, every process woken up through the wait queue must ensure that the next waiter down the line is woken when it has finished. Interruptible waiters don't do that when aborting due to a signal. And if an aborting waiter is concurrently woken up through the waitqueue, noone will ever wake up the next waiter. This has been observed with __wait_on_bit_lock() used by lock_page_killable(): the first contender on the queue was aborting when the actual lock holder woke it up concurrently. The aborted contender didn't acquire the lock and therefor never did an unlock followed by waking up the next waiter. Add abort_exclusive_wait() which removes the process' wait descriptor from the waitqueue, iff still queued, or wakes up the next waiter otherwise. It does so under the waitqueue lock. Racing with a wake up means the aborting process is either already woken (removed from the queue) and will wake up the next waiter, or it will remove itself from the queue and the concurrent wake up will apply to the next waiter after it. Use abort_exclusive_wait() in __wait_event_interruptible_exclusive() and __wait_on_bit_lock() when they were interrupted by other means than a wake up through the queue. [akpm@linux-foundation.org: coding-style fixes] Reported-by: Chris Mason <chris.mason@oracle.com> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Mentored-by: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Chuck Lever <cel@citi.umich.edu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: <stable@kernel.org> ["after some testing"] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16wait: kill is_sync_wait()Tejun Heo
is_sync_wait() is used to distinguish between sync and async waits. Basically sync waits are the ones initialized with init_waitqueue_entry() and async ones with init_waitqueue_func_entry(). The sync/async distinction is used only in prepare_to_wait[_exclusive]() and its only function is to skip setting the current task state if the wait is async. This has a few problems. * No one uses it. None of func_entry users use prepare_to_wait() functions, so the code path never gets executed. * The distinction is bogus. Maybe back when func_entry is used only by aio but it's now also used by epoll and in future possibly by 9p and poll/select. * Taking @state as argument and ignoring it silenly depending on how @wait is initialized is just a bad error-prone API. * It prevents func_entry waits from using wait->private for no good reason. This patch kills is_sync_wait() and the associated code paths from prepare_to_wait[_exclusive](). As there was no user of these code paths, this patch doesn't cause any behavior difference. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08kernel: remove fastcall in kernel/*Harvey Harrison
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-06wait: Use TASK_NORMALMatthew Wilcox
Also move wake_up_locked() to be with the related functions Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-05-09Fix occurrences of "the the "Michael Opdenacker
Signed-off-by: Michael Opdenacker <michael@free-electrons.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-07-10[PATCH] uninline init_waitqueue_head()Ingo Molnar
allyesconfig vmlinux size delta: text data bss dec filename 20736884 6073834 3075176 29885894 vmlinux.before 20721009 6073966 3075176 29870151 vmlinux.after ~18 bytes per callsite, 15K of text size (~0.1%) saved. (as an added bonus this also removes a lockdep annotation.) Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03[PATCH] lockdep: annotate waitqueuesIngo Molnar
Create one lock class for all waitqueue locks in the kernel. Has no effect on non-lockdep kernels. 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>
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>
2004-10-18[PATCH] document wake_up_bit()'s requirement for preceding memory barriersWilliam Lee Irwin III
Document the requirement to use a memory barrier prior to wake_up_bit(). Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2004-10-18[PATCH] reduce number of parameters to __wait_on_bit() and __wait_on_bit_lock()William Lee Irwin III
Some of the parameters to __wait_on_bit() and __wait_on_bit_lock() are redundant, as the wait_bit_queue parameter holds the flags word and the bit number. This patch updates __wait_on_bit() and __wait_on_bit_lock() to fetch that information from the wait_bit_queue passed to them and so reduce the number of parameters so that -mregparm may be more effective. Incremental atop the complete out-of-lining of the contention cases and the fastcall and wait_on_bit_lock()/test_and_set_bit() fixes. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2004-10-18[PATCH] move wait ops' contention case completely out of lineWilliam Lee Irwin III
Move the slow paths of wait_on_bit() and wait_on_bit_lock() out of line. Also uninline wake_up_bit() to reduce the number of callsites generated, and adjust loop startup in __wait_on_bit_lock() to properly reflect its usage in the contention case. Incremental atop the fastcall and wait_on_bit_lock()/test_and_set_bit() fixes. Successfully tested on x86-64. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2004-10-18[PATCH] eliminate inode waitqueue hashtableWilliam Lee Irwin III
Eliminate the inode waitqueue hashtable using bit_waitqueue() via wait_on_bit() and wake_up_bit() to locate the waitqueue head associated with a bit. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2004-10-18[PATCH] eliminate bh waitqueue hashtableWilliam Lee Irwin III
Eliminate the bh waitqueue hashtable using bit_waitqueue() via wait_on_bit() and wake_up_bit() to locate the waitqueue head associated with a bit. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2004-10-18[PATCH] consolidate bit waiting code patternsWilliam Lee Irwin III
Consolidate bit waiting code patterns for page waitqueues using __wait_on_bit() and __wait_on_bit_lock(). Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2004-10-18[PATCH] standardize bit waiting data typeWilliam Lee Irwin III
Eliminate specialized page and bh waitqueue hashing structures in favor of a standardized structure, using wake_up_bit() to wake waiters using the standardized wait_bit_key structure. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2004-10-18[PATCH] move waitqueue functions to kernel/wait.cWilliam Lee Irwin III
The following patch series consolidates the various instances of waitqueue hashing to use a uniform structure and share the per-zone hashtable among all waitqueue hashers. This is expected to increase the number of hashtable buckets available for waiting on bh's and inodes and eliminate statically allocated kernel data structures for greater node locality and reduced kernel image size. Some attempt was made to look similar to Oleg Nesterov's suggested API in order to provide some kind of credit for independent invention of something very similar (the original versions of these patches predated my public postings on the subject of filtered waitqueues). These patches have the further benefit and intention of enabling aio to use filtered wakeups by standardizing the data structure passed to wake functions so that embedded waitqueue elements in aio structures may be succesfully passed to the filtered wakeup wake functions, though this patch series doesn't implement that particular functionality. Successfully stress-tested on x86-64, and ia64 in recent prior versions. This patch: Move waitqueue -related functions not needing static functions in sched.c to kernel/wait.c Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>