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Subject[PATCH tip/core/rcu 08/10] rcu: Remove "cpu" argument to rcu_prepare_for_idle()
Date
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

The "cpu" argument to rcu_prepare_for_idle() is always the current
CPU, so drop it. This in turn allows two of the uses of "cpu" in
this function to be replaced with a this_cpu_ptr() and the third by
smp_processor_id(), replacing that of the call to rcu_prepare_for_idle().
Again, the anticipated cross-CPU uses of these functions has been replaced
by NO_HZ_FULL.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
kernel/rcu/tree.c | 2 +-
kernel/rcu/tree.h | 2 +-
kernel/rcu/tree_plugin.h | 10 +++++-----
3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index d678a98caf1d..8251938fb4ae 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -531,7 +531,7 @@ static void rcu_eqs_enter_common(long long oldval, bool user)
rdp = this_cpu_ptr(rsp->rda);
do_nocb_deferred_wakeup(rdp);
}
- rcu_prepare_for_idle(smp_processor_id());
+ rcu_prepare_for_idle();
/* CPUs seeing atomic_inc() must see prior RCU read-side crit sects */
smp_mb__before_atomic(); /* See above. */
atomic_inc(&rdtp->dynticks);
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 238ac39053fc..8bc3cacbe14a 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -580,7 +580,7 @@ static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
static void __init rcu_spawn_boost_kthreads(void);
static void rcu_prepare_kthreads(int cpu);
static void rcu_cleanup_after_idle(int cpu);
-static void rcu_prepare_for_idle(int cpu);
+static void rcu_prepare_for_idle(void);
static void rcu_idle_count_callbacks_posted(void);
static void print_cpu_stall_info_begin(void);
static void print_cpu_stall_info(struct rcu_state *rsp, int cpu);
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 1797b76cb3ff..5e68ab5fe317 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -1531,7 +1531,7 @@ static void rcu_cleanup_after_idle(int cpu)
* Do the idle-entry grace-period work, which, because CONFIG_RCU_FAST_NO_HZ=n,
* is nothing.
*/
-static void rcu_prepare_for_idle(int cpu)
+static void rcu_prepare_for_idle(void)
{
}

@@ -1666,12 +1666,12 @@ int rcu_needs_cpu(unsigned long *dj)
*
* The caller must have disabled interrupts.
*/
-static void rcu_prepare_for_idle(int cpu)
+static void rcu_prepare_for_idle(void)
{
#ifndef CONFIG_RCU_NOCB_CPU_ALL
bool needwake;
struct rcu_data *rdp;
- struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu);
+ struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
struct rcu_node *rnp;
struct rcu_state *rsp;
int tne;
@@ -1688,7 +1688,7 @@ static void rcu_prepare_for_idle(int cpu)
return;

/* If this is a no-CBs CPU, no callbacks, just return. */
- if (rcu_is_nocb_cpu(cpu))
+ if (rcu_is_nocb_cpu(smp_processor_id()))
return;

/*
@@ -1712,7 +1712,7 @@ static void rcu_prepare_for_idle(int cpu)
return;
rdtp->last_accelerate = jiffies;
for_each_rcu_flavor(rsp) {
- rdp = per_cpu_ptr(rsp->rda, cpu);
+ rdp = this_cpu_ptr(rsp->rda);
if (!*rdp->nxttail[RCU_DONE_TAIL])
continue;
rnp = rdp->mynode;
--
1.8.1.5


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