doc: Improve rcu_dynticks::dynticks documentation
authorJoel Fernandes (Google) <joel@joelfernandes.org>
Sun, 24 Jun 2018 19:34:51 +0000 (12:34 -0700)
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Wed, 29 Aug 2018 15:54:30 +0000 (08:54 -0700)
commitea24c125fe79fd966a4f59768d3d70142a9eb18d
tree4f0b51423d81013796d0ef18a5afdedce5e09d3e
parenta5a2889544997d3909480d6d27e2559875226532
doc: Improve rcu_dynticks::dynticks documentation

The very useful RCU Data-Structures describes that the dynticks counter
of the rcu_dynticks data structure is incremented when we transitions to
or from dynticks-idle mode. However it doesn't mention that it is also
incremented due to transitions to and from user mode which for dynticks
purposes is an extended quiescent state.

I found this with tracing calls to rcu_dynticks_eqs_enter which can also
happen from rcu_user_enter. Lets add this information to the
Data-Structures document.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Documentation/RCU/Design/Data-Structures/Data-Structures.html