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>
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index b310655..3245b40 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -868,49 +868,52 @@
*/
static void rcu_torture_shuffle_tasks(void)
{
- cpumask_t tmp_mask;
+ cpumask_var_t tmp_mask;
int i;
- cpus_setall(tmp_mask);
+ if (!alloc_cpumask_var(&tmp_mask, GFP_KERNEL))
+ BUG();
+
+ cpumask_setall(tmp_mask);
get_online_cpus();
/* No point in shuffling if there is only one online CPU (ex: UP) */
- if (num_online_cpus() == 1) {
- put_online_cpus();
- return;
- }
+ if (num_online_cpus() == 1)
+ goto out;
if (rcu_idle_cpu != -1)
- cpu_clear(rcu_idle_cpu, tmp_mask);
+ cpumask_clear_cpu(rcu_idle_cpu, tmp_mask);
- set_cpus_allowed_ptr(current, &tmp_mask);
+ set_cpus_allowed_ptr(current, tmp_mask);
if (reader_tasks) {
for (i = 0; i < nrealreaders; i++)
if (reader_tasks[i])
set_cpus_allowed_ptr(reader_tasks[i],
- &tmp_mask);
+ tmp_mask);
}
if (fakewriter_tasks) {
for (i = 0; i < nfakewriters; i++)
if (fakewriter_tasks[i])
set_cpus_allowed_ptr(fakewriter_tasks[i],
- &tmp_mask);
+ tmp_mask);
}
if (writer_task)
- set_cpus_allowed_ptr(writer_task, &tmp_mask);
+ set_cpus_allowed_ptr(writer_task, tmp_mask);
if (stats_task)
- set_cpus_allowed_ptr(stats_task, &tmp_mask);
+ set_cpus_allowed_ptr(stats_task, tmp_mask);
if (rcu_idle_cpu == -1)
rcu_idle_cpu = num_online_cpus() - 1;
else
rcu_idle_cpu--;
+out:
put_online_cpus();
+ free_cpumask_var(tmp_mask);
}
/* Shuffle tasks across CPUs, with the intent of allowing each CPU in the