rcu/nocb: Move rcu_nocb_is_setup to rcu_state

This commit moves the RCU nocb initialization witness within rcu_state
to consolidate RCU's global state.

Reported-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 926673ebe355f123c1b0a76d6aaed4c211f9dcd6..f6a3d54585c94491f1e50bf231e99d5001299b12 100644 (file)
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -364,6 +364,7 @@ struct rcu_state {
        arch_spinlock_t ofl_lock ____cacheline_internodealigned_in_smp;
                                                /* Synchronize offline with */
                                                /*  GP pre-initialization. */
+       int nocb_is_setup;                      /* nocb is setup from boot */
 };
 
 /* Values for rcu_state structure's gp_flags field. */

diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h
index 02e1d05a11fc71ca27040f7c33c0b3c53daa9efa..3c00240833d62554df34022d445d0bc5d3b84f35 100644 (file)
--- a/kernel/rcu/tree_nocb.h
+++ b/kernel/rcu/tree_nocb.h
@@ -60,9 +60,6 @@ static inline bool rcu_current_is_nocb_kthread(struct rcu_data *rdp)
  * Parse the boot-time rcu_nocb_mask CPU list from the kernel parameters.
  * If the list is invalid, a warning is emitted and all CPUs are offloaded.
  */
-
-static bool rcu_nocb_is_setup;
-
 static int __init rcu_nocb_setup(char *str)
 {
        alloc_bootmem_cpumask_var(&rcu_nocb_mask);
@@ -72,7 +69,7 @@ static int __init rcu_nocb_setup(char *str)
                        cpumask_setall(rcu_nocb_mask);
                }
        }
-       rcu_nocb_is_setup = true;
+       rcu_state.nocb_is_setup = true;
        return 1;
 }
 __setup("rcu_nocbs", rcu_nocb_setup);
@@ -1172,10 +1169,10 @@ void __init rcu_init_nohz(void)
                                return;
                        }
                }
-               rcu_nocb_is_setup = true;
+               rcu_state.nocb_is_setup = true;
        }
 
-       if (!rcu_nocb_is_setup)
+       if (!rcu_state.nocb_is_setup)
                return;
 
 #if defined(CONFIG_NO_HZ_FULL)
@@ -1233,7 +1230,7 @@ static void rcu_spawn_cpu_nocb_kthread(int cpu)
        struct task_struct *t;
        struct sched_param sp;
 
-       if (!rcu_scheduler_fully_active || !rcu_nocb_is_setup)
+       if (!rcu_scheduler_fully_active || !rcu_state.nocb_is_setup)
                return;
 
        /* If there already is an rcuo kthread, then nothing to do. */
@@ -1279,7 +1276,7 @@ static void __init rcu_spawn_nocb_kthreads(void)
 {
        int cpu;
 
-       if (rcu_nocb_is_setup) {
+       if (rcu_state.nocb_is_setup) {
                for_each_online_cpu(cpu)
                        rcu_spawn_cpu_nocb_kthread(cpu);
        }