From: "Paul E. McKenney" <paul...@linux.vnet.ibm.com>
The "cpu" argument to rcu_needs_cpu() is always the current CPU, so drop
it. This in turn allows the "cpu" argument to rcu_cpu_has_callbacks()
to be removed, which allows the uses of "cpu" in both functions to be
replaced with a this_cpu_ptr(). Again, the anticipated cross-CPU uses
of these functions has been replaced by NO_HZ_FULL.
Signed-off-by: Paul E. McKenney <paul...@linux.vnet.ibm.com>
---
include/linux/rcupdate.h | 2 +-
include/linux/rcutree.h | 2 +-
kernel/rcu/tree.c | 4 ++--
kernel/rcu/tree_plugin.h | 12 ++++++------
kernel/time/tick-sched.c | 2 +-
5 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index b4ad275d90d0..4eb810832b19 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -1103,7 +1103,7 @@ static inline notrace void
rcu_read_unlock_sched_notrace(void)
__kfree_rcu(&((ptr)->rcu_head), offsetof(typeof(*(ptr)), rcu_head))
#if defined(CONFIG_TINY_RCU) || defined(CONFIG_RCU_NOCB_CPU_ALL)
-static inline int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies)
+static inline int rcu_needs_cpu(unsigned long *delta_jiffies)
{
*delta_jiffies = ULONG_MAX;
return 0;
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index 7b5484db1857..52953790dcca 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -32,7 +32,7 @@
void rcu_note_context_switch(void);
#ifndef CONFIG_RCU_NOCB_CPU_ALL
-int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies);
+int rcu_needs_cpu(unsigned long *delta_jiffies);
#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
void rcu_cpu_stall_reset(void);
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index b591f1459240..d678a98caf1d 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3159,7 +3159,7 @@ static int rcu_pending(void)
* non-NULL, store an indication of whether all callbacks are lazy.
* (If there are no callbacks, all of them are deemed to be lazy.)
*/
-static int __maybe_unused rcu_cpu_has_callbacks(int cpu, bool *all_lazy)
+static int __maybe_unused rcu_cpu_has_callbacks(bool *all_lazy)
{
bool al = true;
bool hc = false;
@@ -3167,7 +3167,7 @@ static int __maybe_unused rcu_cpu_has_callbacks(int cpu,
bool *all_lazy)
struct rcu_state *rsp;
for_each_rcu_flavor(rsp) {
- rdp = per_cpu_ptr(rsp->rda, cpu);
+ rdp = this_cpu_ptr(rsp->rda);
if (!rdp->nxtlist)
continue;
hc = true;
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 495d4cce47a7..1797b76cb3ff 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -1512,10 +1512,10 @@ static void rcu_prepare_kthreads(int cpu)
* any flavor of RCU.
*/
#ifndef CONFIG_RCU_NOCB_CPU_ALL
-int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies)
+int rcu_needs_cpu(unsigned long *delta_jiffies)
{
*delta_jiffies = ULONG_MAX;
- return rcu_cpu_has_callbacks(cpu, NULL);
+ return rcu_cpu_has_callbacks(NULL);
}
#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
@@ -1624,15 +1624,15 @@ static bool __maybe_unused rcu_try_advance_all_cbs(void)
* The caller must have disabled interrupts.
*/
#ifndef CONFIG_RCU_NOCB_CPU_ALL
-int rcu_needs_cpu(int cpu, unsigned long *dj)
+int rcu_needs_cpu(unsigned long *dj)
{
- struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu);
+ struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
/* Snapshot to detect later posting of non-lazy callback. */
rdtp->nonlazy_posted_snap = rdtp->nonlazy_posted;
/* If no callbacks, RCU doesn't need the CPU. */
- if (!rcu_cpu_has_callbacks(cpu, &rdtp->all_lazy)) {
+ if (!rcu_cpu_has_callbacks(&rdtp->all_lazy)) {
*dj = ULONG_MAX;
return 0;
}
@@ -1679,7 +1679,7 @@ static void rcu_prepare_for_idle(int cpu)
/* Handle nohz enablement switches conservatively. */
tne = ACCESS_ONCE(tick_nohz_active);
if (tne != rdtp->tick_nohz_enabled_snap) {
- if (rcu_cpu_has_callbacks(cpu, NULL))
+ if (rcu_cpu_has_callbacks(NULL))
invoke_rcu_core(); /* force nohz to see update. */
rdtp->tick_nohz_enabled_snap = tne;
return;
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 7b5741fc4110..1f4356037a7d 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -585,7 +585,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched
*ts,
last_jiffies = jiffies;
} while (read_seqretry(&jiffies_lock, seq));
- if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) ||
+ if (rcu_needs_cpu(&rcu_delta_jiffies) ||
arch_needs_cpu() || irq_work_needs_cpu()) {
next_jiffies = last_jiffies + 1;
delta_jiffies = 1;
--
1.8.1.5
--
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