tree bd3d6a8f21e576a94d1e1812c5c5317f62d1c96d
parent 84a8f446ffd70c2799a96268aaa4d47c22a83ff0
author Paul E. McKenney <paulmck@linux.vnet.ibm.com> 1407199430 -0700
committer Paul E. McKenney <paulmck@linux.vnet.ibm.com> 1410132450 -0700

rcu: Make TASKS_RCU handle nohz_full= CPUs

Currently TASKS_RCU would ignore a CPU running a task in nohz_full=
usermode execution.  There would be neither a context switch nor a
scheduling-clock interrupt to tell TASKS_RCU that the task in question
had passed through a quiescent state.  The grace period would therefore
extend indefinitely.  This commit therefore makes RCU's dyntick-idle
subsystem record the task_struct structure of the task that is running
in dyntick-idle mode on each CPU.  The TASKS_RCU grace period can
then access this information and record a quiescent state on
behalf of any CPU running in dyntick-idle usermode.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>