Commit 94dea151 authored by Marta Rybczynska's avatar Marta Rybczynska Committed by Jonathan Corbet
Browse files

Documentation/locking/locktypes: fix local_locks documentation 



Fix issues with local_locks documentation:
- fix function names, local_lock.h has local_unlock_irqrestore(),
not local_lock_irqrestore()
- fix mapping table, local_unlock_irqrestore() maps to local_irq_restore(),
not _save()

Signed-off-by: default avatarMarta Rybczynska <rybczynska@gmail.com>
Acked-by: default avatarWill Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/CAApg2=SKxQ3Sqwj6TZnV-0x0cKLXFKDaPvXT4N15MPDMKq724g@mail.gmail.com


Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
parent 9123e3a7

Documentation/locking/locktypes.rst

+12 −12
Original line number Diff line number Diff line
@@ -164,14 +164,14 @@ by disabling preemption or interrupts. 
On non-PREEMPT_RT kernels local_lock operations map to the preemption and

interrupt disabling and enabling primitives:



 =========================== ======================

 ===============================  ======================

 local_lock(&llock)               preempt_disable()

 local_unlock(&llock)             preempt_enable()

 local_lock_irq(&llock)           local_irq_disable()

 local_unlock_irq(&llock)         local_irq_enable()

 local_lock_save(&llock)     local_irq_save()

 local_lock_restore(&llock)  local_irq_save()

 =========================== ======================

 local_lock_irqsave(&llock)       local_irq_save()

 local_unlock_irqrestore(&llock)  local_irq_restore()

 ===============================  ======================



The named scope of local_lock has two advantages over the regular

primitives:
@@ -353,14 +353,14 @@ protection scope. So the following substitution is wrong:: 
  {

    local_irq_save(flags);    -> local_lock_irqsave(&local_lock_1, flags);

    func3();

    local_irq_restore(flags); -> local_lock_irqrestore(&local_lock_1, flags);

    local_irq_restore(flags); -> local_unlock_irqrestore(&local_lock_1, flags);

  }



  func2()

  {

    local_irq_save(flags);    -> local_lock_irqsave(&local_lock_2, flags);

    func3();

    local_irq_restore(flags); -> local_lock_irqrestore(&local_lock_2, flags);

    local_irq_restore(flags); -> local_unlock_irqrestore(&local_lock_2, flags);

  }



  func3()
@@ -379,14 +379,14 @@ PREEMPT_RT-specific semantics of spinlock_t. The correct substitution is:: 
  {

    local_irq_save(flags);    -> local_lock_irqsave(&local_lock, flags);

    func3();

    local_irq_restore(flags); -> local_lock_irqrestore(&local_lock, flags);

    local_irq_restore(flags); -> local_unlock_irqrestore(&local_lock, flags);

  }



  func2()

  {

    local_irq_save(flags);    -> local_lock_irqsave(&local_lock, flags);

    func3();

    local_irq_restore(flags); -> local_lock_irqrestore(&local_lock, flags);

    local_irq_restore(flags); -> local_unlock_irqrestore(&local_lock, flags);

  }



  func3()

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