mirror of
https://github.com/followmsi/android_kernel_google_msm.git
synced 2024-09-21 04:00:29 +00:00
rcu: Document same-context read-side constraints
The intent is that a given RCU read-side critical section be confined to a single context. For example, it is illegal to invoke rcu_read_lock() in an exception handler and then invoke rcu_read_unlock() from the context of the task that received the exception. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
parent
f0e7c19db8
commit
3842a0832a
|
@ -265,6 +265,11 @@ extern int debug_lockdep_rcu_enabled(void);
|
||||||
*
|
*
|
||||||
* Checks debug_lockdep_rcu_enabled() to prevent false positives during boot
|
* Checks debug_lockdep_rcu_enabled() to prevent false positives during boot
|
||||||
* and while lockdep is disabled.
|
* and while lockdep is disabled.
|
||||||
|
*
|
||||||
|
* Note that rcu_read_lock() and the matching rcu_read_unlock() must
|
||||||
|
* occur in the same context, for example, it is illegal to invoke
|
||||||
|
* rcu_read_unlock() in process context if the matching rcu_read_lock()
|
||||||
|
* was invoked from within an irq handler.
|
||||||
*/
|
*/
|
||||||
static inline int rcu_read_lock_held(void)
|
static inline int rcu_read_lock_held(void)
|
||||||
{
|
{
|
||||||
|
@ -689,6 +694,11 @@ static inline void rcu_read_unlock(void)
|
||||||
* critical sections in interrupt context can use just rcu_read_lock(),
|
* critical sections in interrupt context can use just rcu_read_lock(),
|
||||||
* though this should at least be commented to avoid confusing people
|
* though this should at least be commented to avoid confusing people
|
||||||
* reading the code.
|
* reading the code.
|
||||||
|
*
|
||||||
|
* Note that rcu_read_lock_bh() and the matching rcu_read_unlock_bh()
|
||||||
|
* must occur in the same context, for example, it is illegal to invoke
|
||||||
|
* rcu_read_unlock_bh() from one task if the matching rcu_read_lock_bh()
|
||||||
|
* was invoked from some other task.
|
||||||
*/
|
*/
|
||||||
static inline void rcu_read_lock_bh(void)
|
static inline void rcu_read_lock_bh(void)
|
||||||
{
|
{
|
||||||
|
@ -716,6 +726,11 @@ static inline void rcu_read_unlock_bh(void)
|
||||||
* are being done using call_rcu_sched() or synchronize_rcu_sched().
|
* are being done using call_rcu_sched() or synchronize_rcu_sched().
|
||||||
* Read-side critical sections can also be introduced by anything that
|
* Read-side critical sections can also be introduced by anything that
|
||||||
* disables preemption, including local_irq_disable() and friends.
|
* disables preemption, including local_irq_disable() and friends.
|
||||||
|
*
|
||||||
|
* Note that rcu_read_lock_sched() and the matching rcu_read_unlock_sched()
|
||||||
|
* must occur in the same context, for example, it is illegal to invoke
|
||||||
|
* rcu_read_unlock_sched() from process context if the matching
|
||||||
|
* rcu_read_lock_sched() was invoked from an NMI handler.
|
||||||
*/
|
*/
|
||||||
static inline void rcu_read_lock_sched(void)
|
static inline void rcu_read_lock_sched(void)
|
||||||
{
|
{
|
||||||
|
|
|
@ -158,6 +158,11 @@ static inline int srcu_read_lock_held(struct srcu_struct *sp)
|
||||||
* one way to indirectly wait on an SRCU grace period is to acquire
|
* one way to indirectly wait on an SRCU grace period is to acquire
|
||||||
* a mutex that is held elsewhere while calling synchronize_srcu() or
|
* a mutex that is held elsewhere while calling synchronize_srcu() or
|
||||||
* synchronize_srcu_expedited().
|
* synchronize_srcu_expedited().
|
||||||
|
*
|
||||||
|
* Note that srcu_read_lock() and the matching srcu_read_unlock() must
|
||||||
|
* occur in the same context, for example, it is illegal to invoke
|
||||||
|
* srcu_read_unlock() in an irq handler if the matching srcu_read_lock()
|
||||||
|
* was invoked in process context.
|
||||||
*/
|
*/
|
||||||
static inline int srcu_read_lock(struct srcu_struct *sp) __acquires(sp)
|
static inline int srcu_read_lock(struct srcu_struct *sp) __acquires(sp)
|
||||||
{
|
{
|
||||||
|
|
Loading…
Reference in a new issue