linux-toradex.git/lib/rwsem-spinlock.c, branch v3.0.95

rwsem generic spinlock: use IRQ save/restore spinlocks

2010-04-07T23:15:05+00:00

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

rwsem: fix rwsem_is_locked() bugs

2009-12-15T16:53:26+00:00

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

rwsem-spinlock: remove useless function exports

2009-12-15T16:53:26+00:00

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

lib: remove fastcall from lib/*

2008-02-08T17:22:31+00:00

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Harvey Harrison 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Lockdep: add lockdep_set_class_and_subclass() and lockdep_set_subclass()

2006-10-11T05:45:14+00:00

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

[PATCH] lockdep: prove rwsem locking correctness

2006-07-03T22:27:04+00:00

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

[PATCH] lockdep: clean up rwsems

2006-07-03T22:27:01+00:00

Clean up rwsems.

Signed-off-by: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] use smp_mb/wmb/rmb where possible

2005-05-01T15:58:47+00:00

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

Linux-2.6.12-rc2

2005-04-16T22:20:36+00:00

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!