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/rcupreempt.c b/kernel/rcupreempt.c
index 0498265..f9dc8f3 100644
--- a/kernel/rcupreempt.c
+++ b/kernel/rcupreempt.c
@@ -164,7 +164,8 @@
{ "idle", "waitack", "waitzero", "waitmb" };
#endif /* #ifdef CONFIG_RCU_TRACE */
-static cpumask_t rcu_cpu_online_map __read_mostly = CPU_MASK_NONE;
+static DECLARE_BITMAP(rcu_cpu_online_map, NR_CPUS) __read_mostly
+ = CPU_BITS_NONE;
/*
* Enum and per-CPU flag to determine when each CPU has seen
@@ -758,7 +759,7 @@
/* Now ask each CPU for acknowledgement of the flip. */
- for_each_cpu_mask_nr(cpu, rcu_cpu_online_map) {
+ for_each_cpu(cpu, to_cpumask(rcu_cpu_online_map)) {
per_cpu(rcu_flip_flag, cpu) = rcu_flipped;
dyntick_save_progress_counter(cpu);
}
@@ -776,7 +777,7 @@
int cpu;
RCU_TRACE_ME(rcupreempt_trace_try_flip_a1);
- for_each_cpu_mask_nr(cpu, rcu_cpu_online_map)
+ for_each_cpu(cpu, to_cpumask(rcu_cpu_online_map))
if (rcu_try_flip_waitack_needed(cpu) &&
per_cpu(rcu_flip_flag, cpu) != rcu_flip_seen) {
RCU_TRACE_ME(rcupreempt_trace_try_flip_ae1);
@@ -808,7 +809,7 @@
/* Check to see if the sum of the "last" counters is zero. */
RCU_TRACE_ME(rcupreempt_trace_try_flip_z1);
- for_each_cpu_mask_nr(cpu, rcu_cpu_online_map)
+ for_each_cpu(cpu, to_cpumask(rcu_cpu_online_map))
sum += RCU_DATA_CPU(cpu)->rcu_flipctr[lastidx];
if (sum != 0) {
RCU_TRACE_ME(rcupreempt_trace_try_flip_ze1);
@@ -823,7 +824,7 @@
smp_mb(); /* ^^^^^^^^^^^^ */
/* Call for a memory barrier from each CPU. */
- for_each_cpu_mask_nr(cpu, rcu_cpu_online_map) {
+ for_each_cpu(cpu, to_cpumask(rcu_cpu_online_map)) {
per_cpu(rcu_mb_flag, cpu) = rcu_mb_needed;
dyntick_save_progress_counter(cpu);
}
@@ -843,7 +844,7 @@
int cpu;
RCU_TRACE_ME(rcupreempt_trace_try_flip_m1);
- for_each_cpu_mask_nr(cpu, rcu_cpu_online_map)
+ for_each_cpu(cpu, to_cpumask(rcu_cpu_online_map))
if (rcu_try_flip_waitmb_needed(cpu) &&
per_cpu(rcu_mb_flag, cpu) != rcu_mb_done) {
RCU_TRACE_ME(rcupreempt_trace_try_flip_me1);
@@ -1032,7 +1033,7 @@
RCU_DATA_CPU(cpu)->rcu_flipctr[0] = 0;
RCU_DATA_CPU(cpu)->rcu_flipctr[1] = 0;
- cpu_clear(cpu, rcu_cpu_online_map);
+ cpumask_clear_cpu(cpu, to_cpumask(rcu_cpu_online_map));
spin_unlock_irqrestore(&rcu_ctrlblk.fliplock, flags);
@@ -1072,7 +1073,7 @@
struct rcu_data *rdp;
spin_lock_irqsave(&rcu_ctrlblk.fliplock, flags);
- cpu_set(cpu, rcu_cpu_online_map);
+ cpumask_set_cpu(cpu, to_cpumask(rcu_cpu_online_map));
spin_unlock_irqrestore(&rcu_ctrlblk.fliplock, flags);
/*
@@ -1430,7 +1431,7 @@
* We don't need protection against CPU-Hotplug here
* since
* a) If a CPU comes online while we are iterating over the
- * cpu_online_map below, we would only end up making a
+ * cpu_online_mask below, we would only end up making a
* duplicate call to rcu_online_cpu() which sets the corresponding
* CPU's mask in the rcu_cpu_online_map.
*