...
bool need_rcu_nocb_mask = false;
//#if defined(CONFIG_NO_HZ_FULL)
if (tick_nohz_full_running && !cpumask_empty(tick_nohz_full_mask))
need_rcu_nocb_mask = true; <---- //Move it here
//#endif |
|
if (need_rcu_nocb_mask) { | //Can only be true above
... -----
}
The local variable 'need_rcu_nocb_mask' is true only if CONFIG_NO_HZ_FULL
is defined. So branch "if (need_rcu_nocb_mask)" can be moved within the
scope of "#if defined(CONFIG_NO_HZ_FULL)". At this point, using variable
'need_rcu_nocb_mask' is not necessary, so delete it.
No functional changes, but the code looks a little more concise.
The kernel built with CONFIG_NO_HZ_FULL=n and CONFIG_RCU_NOCB_CPU=y ran
continuously for a whole day, no errors were reported.
Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
---
kernel/rcu/tree_nocb.h | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
v1 --> v2:
Update commit message.
diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h
index 46694e13398a3ee..e7fe99eb58972a6 100644
--- a/kernel/rcu/tree_nocb.h
+++ b/kernel/rcu/tree_nocb.h
@@ -1154,15 +1154,10 @@ EXPORT_SYMBOL_GPL(rcu_nocb_cpu_offload);
void __init rcu_init_nohz(void)
{
int cpu;
- bool need_rcu_nocb_mask = false;
struct rcu_data *rdp;
#if defined(CONFIG_NO_HZ_FULL)
- if (tick_nohz_full_running && !cpumask_empty(tick_nohz_full_mask))
- need_rcu_nocb_mask = true;
-#endif /* #if defined(CONFIG_NO_HZ_FULL) */
-
- if (need_rcu_nocb_mask) {
+ if (tick_nohz_full_running && !cpumask_empty(tick_nohz_full_mask)) {
if (!cpumask_available(rcu_nocb_mask)) {
if (!zalloc_cpumask_var(&rcu_nocb_mask, GFP_KERNEL)) {
pr_info("rcu_nocb_mask allocation failed, callback offloading disabled.\n");
@@ -1171,6 +1166,7 @@ void __init rcu_init_nohz(void)
}
rcu_state.nocb_is_setup = true;
}
+#endif /* #if defined(CONFIG_NO_HZ_FULL) */
if (!rcu_state.nocb_is_setup)
return;
--
2.25.1
