include/linux/rcupdate.h

2  * Read-Copy Update mechanism for mutual exclusion
28  * For detailed explanation of Read-Copy Update mechanism see -
86  * period elapses, in other words after all pre-existing RCU read-side
88  * might well execute concurrently with RCU read-side critical sections
89  * that started after call_rcu() was invoked.  RCU read-side critical
110  * read-side critical sections have completed. call_rcu_bh() assumes
111  * that the read-side critical sections end on completion of a softirq
112  * handler. This means that read-side critical sections in process
114  * used when most of the read-side critical sections are in softirq context.
115  * RCU read-side critical sections are delimited by :
131  * read-side critical sections have completed. call_rcu_sched() assumes
132  * that the read-side critical sections end on enabling of preemption
134  * RCU read-side critical sections are delimited by :
258  * rcu_read_lock_held() - might we be in RCU read-side critical section?
261  * read-side critical section.  In absence of CONFIG_DEBUG_LOCK_ALLOC,
262  * this assumes we are in an RCU read-side critical section unless it can
264  * require that they be called within an RCU read-side critical section.
290  * rcu_read_lock_sched_held() - might we be in RCU-sched read-side critical section?
293  * RCU-sched read-side critical section.  In absence of
294  * CONFIG_DEBUG_LOCK_ALLOC, this assumes we are in an RCU-sched read-side
297  * read-side critical section.  This is useful for debug checks in functions
298  * that required that they be called within an RCU-sched read-side
309  * state, so such a CPU is effectively never in an RCU read-side critical
388 				   " read-side critical section");	\
391 				   " read-side critical section");	\
464  * @p: The pointer to read
478  * @p: The pointer to read, prior to dereferencing
485  * An implicit check for being in an RCU read-side critical section
514  * @p: The pointer to read, prior to dereferencing
524  * @p: The pointer to read, prior to dereferencing
537  * @p: The index to read
551  * @p: The pointer to read, prior to dereferencing
562  * Note that this function does not implicitly check for RCU read-side
572  * @p: The pointer to read, prior to dereferencing
593  * @p: The pointer to read, prior to dereferencing
601  * @p: The pointer to read, prior to dereferencing
609  * @p: The pointer to read, prior to dereferencing
616  * rcu_read_lock() - mark the beginning of an RCU read-side critical section
619  * are within RCU read-side critical sections, then the
622  * on one CPU while other CPUs are within RCU read-side critical
627  * with new RCU read-side critical sections.  One way that this can happen
629  * read-side critical section, (2) CPU 1 invokes call_rcu() to register
630  * an RCU callback, (3) CPU 0 exits the RCU read-side critical section,
631  * (4) CPU 2 enters a RCU read-side critical section, (5) the RCU
632  * callback is invoked.  This is legal, because the RCU read-side critical
638  * RCU read-side critical sections may be nested.  Any deferred actions
639  * will be deferred until the outermost RCU read-side critical section
644  * read-side critical section that would block in a !PREEMPT kernel.
645  * But if you want the full story, read on!
648  * is illegal to block while in an RCU read-side critical section.  In
650  * in CONFIG_PREEMPT kernel builds, RCU read-side critical sections may
653  * RCU read-side critical sections may be preempted and they may also
675  * rcu_read_unlock() - marks the end of an RCU read-side critical section.
692  * softirq handler to be a quiescent state, a process in RCU read-side
693  * critical section must be protected by disabling softirqs. Read-side
727  * Read-side critical sections can also be introduced by anything that
781  * will be dereferenced by RCU read-side code.