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Commit 198bbf81 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

rcu: Remove "cpu" argument to rcu_prepare_for_idle() 



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Again, the anticipated cross-CPU uses of these functions has been replaced
by NO_HZ_FULL.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: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: default avatarPranith Kumar <bobby.prani@gmail.com>
parent aa6da514

kernel/rcu/tree.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

kernel/rcu/tree.h

+1 −1
Original line number Diff line number Diff line
@@ -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);

kernel/rcu/tree_plugin.h

+5 −5
Original line number Diff line number Diff line
@@ -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;