| 8292c9e15c3b069459794a04f5e2cf0d5665ddc4 |
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24-Feb-2010 |
Thomas Gleixner <tglx@linutronix.de> |
locking, semaphores: Annotate inner lock as raw
There is no reason to have the spin_lock protecting the semaphore
preemptible on -rt. Annotate it as a raw_spinlock.
In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.
( On rt this also solves lockdep complaining about the
rt_mutex.wait_lock being not initialized. )
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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| 4882720b267b7b1d1b0ce08334b205f0329d4615 |
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07-Sep-2010 |
Thomas Gleixner <tglx@linutronix.de> |
semaphore: Remove mutex emulation
Semaphores used as mutexes have been deprecated for years. Now that
all users are either converted to real semaphores or to mutexes remove
the cruft.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
LKML-Reference: <20100907125057.562399240@linutronix.de>
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| febc88c5948f81114f64c3412011d695aecae233 |
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07-Sep-2010 |
Thomas Gleixner <tglx@linutronix.de> |
semaphore: Add DEFINE_SEMAPHORE
The full cleanup of init_MUTEX[_LOCKED] and DECLARE_MUTEX has not been
done. Some of the users are real semaphores and we should name them as
such instead of confusing everyone with "MUTEX".
Provide the infrastructure to get finally rid of init_MUTEX[_LOCKED]
and DECLARE_MUTEX.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
LKML-Reference: <20100907125054.795929962@linutronix.de>
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| b552068999b0b05087c454e525b30b785c79dc9b |
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23-Apr-2008 |
Matthew Wilcox <matthew@wil.cx> |
Remove __DECLARE_SEMAPHORE_GENERIC
There are no users of __DECLARE_SEMAPHORE_GENERIC in the kernel
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
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| 714493cd5468f42ca3c4f730a9c17c203abd5059 |
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11-Apr-2008 |
Matthew Wilcox <matthew@wil.cx> |
Improve semaphore documentation
Move documentation from semaphore.h to semaphore.c as requested by
Andrew Morton. Also reformat to kernel-doc style and add some more
notes about the implementation.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
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| b17170b2fac96705db3188f093f89e8e838418e4 |
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14-Mar-2008 |
Matthew Wilcox <matthew@wil.cx> |
Simplify semaphore implementation
By removing the negative values of 'count' and relying on the wait_list to
indicate whether we have any waiters, we can simplify the implementation
by removing the protection against an unlikely race condition. Thanks to
David Howells for his suggestions.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
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| f1241c87a16c4fe9f4f51d6ed3589f031c505e8d |
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14-Mar-2008 |
Matthew Wilcox <matthew@wil.cx> |
Add down_timeout and change ACPI to use it
ACPI currently emulates a timeout for semaphores with calls to
down_trylock and sleep. This produces horrible behaviour in terms of
fairness and excessive wakeups. Now that we have a unified semaphore
implementation, adding a real down_trylock is almost trivial.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
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| f06d96865861c3dd01520f47e2e61c899db1631f |
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14-Mar-2008 |
Matthew Wilcox <matthew@wil.cx> |
Introduce down_killable()
down_killable() is the functional counterpart of mutex_lock_killable.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
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| 64ac24e738823161693bf791f87adc802cf529ff |
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08-Mar-2008 |
Matthew Wilcox <matthew@wil.cx> |
Generic semaphore implementation
Semaphores are no longer performance-critical, so a generic C
implementation is better for maintainability, debuggability and
extensibility. Thanks to Peter Zijlstra for fixing the lockdep
warning. Thanks to Harvey Harrison for pointing out that the
unlikely() was unnecessary.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
|