Since there is now a single consolidated RCU flavor, rcutorture
needs to test extending of RCU readers via rcu_read_lock_bh() and
rcu_read_lock_sched().  This commit adds this support, with added checks
(just like for local_bh_enable()) to ensure that rcu_read_unlock_bh()
will not be invoked while interrupts are disabled.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit saves a few lines by consolidating the RCU-sched function
definitions at the end of include/linux/rcupdate.h.  This consolidation
also makes it easier to remove them all when the time comes.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit saves a few lines by consolidating the RCU-bh function
definitions at the end of include/linux/rcupdate.h.  This consolidation
also makes it easier to remove them all when the time comes.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

The rcu_gp_kthread() function is long and deeply indented, so this
commit pulls the loop that repeatedly invokes rcu_gp_fqs() into a new
rcu_gp_fqs_loop() function.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Consolidation of the RCU flavors into one makes increment_cpu_stall_ticks()
a trivial one-line function with only one caller.  This commit therefore
inlines it.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Pointers to rcu_data structures should be named rdp, not rsp.  This
commit therefore makes this change.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Now that there is only one rcu_state structure, there is less point in
maintaining a pointer to it.  This commit therefore replaces rsp with
&rcu_state in rcu_cpu_starting() and rcu_init_one().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Now that there is only one rcu_state structure, there is less point
in maintaining a pointer to it.  This commit therefore replaces rsp
with &rcu_state in rcu_barrier_callback(), rcu_barrier_func(), and
_rcu_barrier().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Now that there is only one rcu_state structure, there is less point in
maintaining a pointer to it.  This commit therefore replaces rsp with
&rcu_state in rcu_report_qs_rnp(), force_quiescent_state(), and
rcu_check_gp_start_stall().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Now that there is only one rcu_state structure, there is less point in
maintaining a pointer to it.  This commit therefore replaces rsp with
&rcu_state in rcu_do_batch(), invoke_rcu_callbacks(), and __call_rcu().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Now that there is only one rcu_state structure, there is less point
in maintaining a pointer to it.  This commit therefore replaces
rsp with &rcu_state in rcu_start_this_gp(), rcu_accelerate_cbs(),
__note_gp_changes(), rcu_gp_init(), rcu_gp_fqs(), rcu_gp_cleanup(),
rcu_gp_kthread(), and rcu_report_qs_rsp().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Now that there is only one rcu_state structure, there is less point
in maintaining a pointer to it.  This commit therefore replaces rsp
with &rcu_state in print_other_cpu_stall(), print_cpu_stall(), and
check_cpu_stall().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit removes the rsp and gpa local variables, repurposes the j
local variable and adds a gpk (GP kthread) local to improve readability.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit restructures rcutorture_get_gp_data() to take advantage of
the fact that there is only one flavor of RCU.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Now that there is only ever a single flavor of RCU in a given kernel
build, there isn't a whole lot of point in having a flavor-traversal
macro.  This commit therefore removes it and converts calls to it to
straightline code, inlining trivial functions as appropriate.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit removes the last non-flavor-traversal rsp local variable from
kernel/rcu/tree_plugin.h in favor of &rcu_state.  The flavor-traversal
locals will be removed with the removal of flavor traversal.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Now that there is only one rcu_state structure, there is no need for the
rcu_data structure to indicate which it corresponds to.  This commit
therefore removes the rcu_data structure's ->rsp field, replacing all
remaining uses of it with &rcu_state.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the Linux
kernel, so there is no need to pass it as a parameter to RCU's rcu_node
tree's accessor macros.  This commit therefore removes the rsp parameter
from those macros in kernel/rcu/rcu.h, and removes some now-unused rsp
local variables while in the area.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to
RCU's functions.  This commit therefore removes the rsp parameter
from the code in kernel/rcu/tree_exp.h, and removes all of the
rsp local variables while in the area.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to
RCU's functions.  This commit therefore removes the rsp parameter
from rcu_nocb_cpu_needs_barrier(), rcu_spawn_one_nocb_kthread(),
rcu_organize_nocb_kthreads(), rcu_nocb_cpu_needs_barrier(), and
rcu_nohz_full_cpu().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
print_cpu_stall_info().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
rcu_spawn_one_boost_kthread().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
dump_blkd_tasks() and rcu_preempt_blocked_readers_cgp().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
rcu_print_detail_task_stall().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
rcu_init_one() and rcu_dump_rcu_node_tree().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of
the Linux kernel, so there is no need to pass it as a parameter
to RCU's functions.  This commit therefore removes the rsp
parameter from rcu_boot_init_percpu_data(), rcu_init_percpu_data(),
rcu_cleanup_dying_idle_cpu(), and rcu_migrate_callbacks().  While in
the neighborhood, line the last three into rcutree_prepare_cpu(),
rcu_report_dead() and rcutree_migrate_callbacks(), respectively.
This also gets rid of the for_each_rcu_flavor() calls that were in
those tree functions.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
_rcu_barrier_trace() and _rcu_barrier().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the Linux
kernel, so there is no need to pass it as a parameter to RCU's functions.
This commit therefore removes the rsp parameter from __rcu_pending(),
and also inlines it into rcu_pending(), removing the for_each_rcu_flavor()
while in the neighborhood..
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
__call_rcu_core() and __call_rcu().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
__rcu_process_callbacks(), and also inlines it into rcu_process_callbacks(),
removing the for_each_rcu_flavor() while in the neighborhood.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
rcu_check_gp_start_stall().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
force_qs_rnp() and force_quiescent_state().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
rcu_do_batch().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
rcu_cleanup_dying_cpu() and rcu_cleanup_dead_cpu().  And, as long as
we are in the neighborhood, inlines them into rcutree_dying_cpu() and
rcutree_dead_cpu(), respectively.  This also eliminates a pair of
for_each_rcu_flavor() loops.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
rcu_check_quiescent_state().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
rcu_gp_init(), rcu_gp_fqs_check_wake(), rcu_gp_fqs(), rcu_gp_cleanup(),
and rcu_gp_kthread().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
rcu_gp_slow().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
note_gp_changes().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
__note_gp_changes().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
rcu_advance_cbs().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>