diff options
| author | Yury Norov | 2022-01-23 10:38:53 -0800 |
|---|---|---|
| committer | Paul E. McKenney | 2022-02-14 10:36:58 -0800 |
| commit | 6a2c1d450a6a328027280a854019c55de989e14e (patch) | |
| tree | 1925663bebf81e6f9681cf7e7be9730dc6f3cc98 | |
| parent | e6339d3b443c436c3b8f45eefec2212a8c07065d (diff) | |
rcu: Replace cpumask_weight with cpumask_empty where appropriate
In some places, RCU code calls cpumask_weight() to check if any bit of a
given cpumask is set. We can do it more efficiently with cpumask_empty()
because cpumask_empty() stops traversing the cpumask as soon as it finds
first set bit, while cpumask_weight() counts all bits unconditionally.
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| -rw-r--r-- | kernel/rcu/tree_nocb.h | 4 | ||||
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 2 |
2 files changed, 3 insertions, 3 deletions
diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h index eeafb546a7a0..f83c7b1d6110 100644 --- a/kernel/rcu/tree_nocb.h +++ b/kernel/rcu/tree_nocb.h @@ -1169,7 +1169,7 @@ void __init rcu_init_nohz(void) struct rcu_data *rdp; #if defined(CONFIG_NO_HZ_FULL) - if (tick_nohz_full_running && cpumask_weight(tick_nohz_full_mask)) + if (tick_nohz_full_running && !cpumask_empty(tick_nohz_full_mask)) need_rcu_nocb_mask = true; #endif /* #if defined(CONFIG_NO_HZ_FULL) */ @@ -1348,7 +1348,7 @@ static void __init rcu_organize_nocb_kthreads(void) */ void rcu_bind_current_to_nocb(void) { - if (cpumask_available(rcu_nocb_mask) && cpumask_weight(rcu_nocb_mask)) + if (cpumask_available(rcu_nocb_mask) && !cpumask_empty(rcu_nocb_mask)) WARN_ON(sched_setaffinity(current->pid, rcu_nocb_mask)); } EXPORT_SYMBOL_GPL(rcu_bind_current_to_nocb); diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 07845dcd33c5..efd0c87d2ffa 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1220,7 +1220,7 @@ static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu) cpu != outgoingcpu) cpumask_set_cpu(cpu, cm); cpumask_and(cm, cm, housekeeping_cpumask(HK_FLAG_RCU)); - if (cpumask_weight(cm) == 0) + if (cpumask_empty(cm)) cpumask_copy(cm, housekeeping_cpumask(HK_FLAG_RCU)); set_cpus_allowed_ptr(t, cm); mutex_unlock(&rnp->boost_kthread_mutex); |