cpumask: convert RCU implementations

Impact: use new cpumask API.

rcu_ctrlblk contains a cpumask, and it's highly optimized so I don't want
a cpumask_var_t (ie. a pointer) for the CONFIG_CPUMASK_OFFSTACK case.  It
could use a dangling bitmap, and be allocated in __rcu_init to save memory,
but for the moment we use a bitmap.

(Eventually 'struct cpumask' will be undefined for CONFIG_CPUMASK_OFFSTACK,
so we use a bitmap here to show we really mean it).

We remove on-stack cpumasks, using cpumask_var_t for
rcu_torture_shuffle_tasks() and for_each_cpu_and in force_quiescent_state().

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/rcuclassic.h b/include/linux/rcuclassic.h
index 301dda829e37..f3f697df1d71 100644
--- a/include/linux/rcuclassic.h
+++ b/include/linux/rcuclassic.h
@@ -59,8 +59,8 @@ struct rcu_ctrlblk {
         int     signaled;
 
         spinlock_t      lock    ____cacheline_internodealigned_in_smp;
-        cpumask_t       cpumask; /* CPUs that need to switch in order    */
-                                 /* for current batch to proceed.        */
+        DECLARE_BITMAP(cpumask, NR_CPUS); /* CPUs that need to switch for */
+                                          /* current batch to proceed.     */
 } ____cacheline_internodealigned_in_smp;
 
 /* Is batch a before batch b ? */