Documentation/RCU/rcu.rst

3 RCU Concepts
6 The basic idea behind RCU (read-copy update) is to split destructive
11 since dropped their references.  For example, an RCU-protected deletion
14 information on using RCU with linked lists.
19 - Why would anyone want to use RCU?
21   The advantage of RCU's two-part approach is that RCU readers need
25   on modern CPUs is what gives RCU its performance advantages
26   in read-mostly situations.  The fact that RCU readers need not
30   if the RCU readers give no indication when they are done?
32   Just as with spinlocks, RCU readers are not permitted to
35   three states, we know that that CPU has exited any previous RCU
41   Preemptible variants of RCU (CONFIG_PREEMPT_RCU) get the
44   RCU read-side critical sections.  SRCU also uses CPU-local
45   counters, and permits general blocking within RCU read-side
46   critical sections.  These variants of RCU detect grace periods
54 - How can I see where RCU is currently used in the Linux kernel?
59   "synchronize_srcu", and the other RCU primitives.  Or grab one
62   (http://www.rdrop.com/users/paulmck/RCU/linuxusage/rculocktab.html).
64 - What guidelines should I follow when writing code that uses RCU?
68 - Why the name "RCU"?
70   "RCU" stands for "read-copy update".
74 - I hear that RCU is patented?  What is with that?
76   Yes, it is.  There are several known patents related to RCU,
77   search for the string "Patent" in Documentation/RCU/RTFP.txt to find them.
81   There are now also LGPL implementations of user-level RCU
84 - I hear that RCU needs work in order to support realtime kernels?
86   Realtime-friendly RCU are enabled via the CONFIG_PREEMPTION
89 - Where can I find more information on RCU?
91   See the Documentation/RCU/RTFP.txt file.