08 Apr, 2010
1 commit
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rwsems can be used with IRQs disabled, particularily in early boot
before IRQs are enabled. Currently the spin_unlock_irq() usage in the
slow-patch will unconditionally enable interrupts and cause problems
since interrupts are not yet initialized or enabled.This patch uses save/restore versions of IRQ spinlocks in the slowpath
to ensure interrupts are not unintentionally disabled.Signed-off-by: Kevin Hilman
Signed-off-by: Linus Torvalds
16 Dec, 2009
2 commits
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rwsem_is_locked() tests ->activity without locks, so we should always keep
->activity consistent. However, the code in __rwsem_do_wake() breaks this
rule, it updates ->activity after _all_ readers waken up, this may give
some reader a wrong ->activity value, thus cause rwsem_is_locked() behaves
wrong.Quote from Andrew:
"
- we have one or more processes sleeping in down_read(), waiting for access.- we wake one or more processes up without altering ->activity
- they start to run and they do rwsem_is_locked(). This incorrectly
returns "false", because the waker process is still crunching away in
__rwsem_do_wake().- the waker now alters ->activity, but it was too late.
"So we need get a spinlock to protect this. And rwsem_is_locked() should
not block, thus we use spin_trylock_irqsave().[akpm@linux-foundation.org: simplify code]
Reported-by: Brian Behlendorf
Cc: Ben Woodard
Cc: David Howells
Signed-off-by: WANG Cong
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
These functions need not to be exported, since no drivers should use them.
__init_rwsem() is an exception, because init_rwsem(), which is a macro,
is used.Signed-off-by: WANG Cong
Cc: David Howells
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Feb, 2008
1 commit
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[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Harvey Harrison
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Oct, 2006
1 commit
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This annotation makes it possible to assign a subclass on lock init. This
annotation is meant to reduce the _nested() annotations by assigning a
default subclass.One could do without this annotation and rely on lockdep_set_class()
exclusively, but that would require a manual stack of struct lock_class_key
objects.Signed-off-by: Peter Zijlstra
Signed-off-by: Dmitry Torokhov
04 Jul, 2006
2 commits
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Use the lock validator framework to prove rwsem locking correctness.
Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Clean up rwsems.
Signed-off-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 May, 2005
1 commit
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Replace a number of memory barriers with smp_ variants. This means we won't
take the unnecessary hit on UP machines.Signed-off-by: Anton Blanchard
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Apr, 2005
1 commit
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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!
