Commit 4580b054 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

rcu: Remove rsp parameter from no-CBs CPU functions 



There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to
RCU's functions.  This commit therefore removes the rsp parameter
from rcu_nocb_cpu_needs_barrier(), rcu_spawn_one_nocb_kthread(),
rcu_organize_nocb_kthreads(), rcu_nocb_cpu_needs_barrier(), and
rcu_nohz_full_cpu().

Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
parent b21ebed9

kernel/rcu/tree.c

+2 −2
Original line number Diff line number Diff line
@@ -3095,7 +3095,7 @@ static int rcu_pending(void) 
	check_cpu_stall(rdp);



	/* Is this CPU a NO_HZ_FULL CPU that should ignore RCU? */

	if (rcu_nohz_full_cpu(&rcu_state))

	if (rcu_nohz_full_cpu())

		return 0;



	/* Is the RCU core waiting for a quiescent state from this CPU? */
@@ -3246,7 +3246,7 @@ static void _rcu_barrier(void) 
			continue;

		rdp = per_cpu_ptr(&rcu_data, cpu);

		if (rcu_is_nocb_cpu(cpu)) {

			if (!rcu_nocb_cpu_needs_barrier(rsp, cpu)) {

			if (!rcu_nocb_cpu_needs_barrier(cpu)) {

				_rcu_barrier_trace(TPS("OfflineNoCB"), cpu,

						   rsp->barrier_sequence);

			} else {

kernel/rcu/tree.h

+3 −3
Original line number Diff line number Diff line
@@ -476,7 +476,7 @@ static void print_cpu_stall_info(int cpu); 
static void print_cpu_stall_info_end(void);

static void zero_cpu_stall_ticks(struct rcu_data *rdp);

static void increment_cpu_stall_ticks(void);

static bool rcu_nocb_cpu_needs_barrier(struct rcu_state *rsp, int cpu);

static bool rcu_nocb_cpu_needs_barrier(int cpu);

static struct swait_queue_head *rcu_nocb_gp_get(struct rcu_node *rnp);

static void rcu_nocb_gp_cleanup(struct swait_queue_head *sq);

static void rcu_init_one_nocb(struct rcu_node *rnp);
@@ -491,11 +491,11 @@ static void rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp); 
static void rcu_spawn_all_nocb_kthreads(int cpu);

static void __init rcu_spawn_nocb_kthreads(void);

#ifdef CONFIG_RCU_NOCB_CPU

static void __init rcu_organize_nocb_kthreads(struct rcu_state *rsp);

static void __init rcu_organize_nocb_kthreads(void);

#endif /* #ifdef CONFIG_RCU_NOCB_CPU */

static bool init_nocb_callback_list(struct rcu_data *rdp);

static void rcu_bind_gp_kthread(void);

static bool rcu_nohz_full_cpu(struct rcu_state *rsp);

static bool rcu_nohz_full_cpu(void);

static void rcu_dynticks_task_enter(void);

static void rcu_dynticks_task_exit(void);

kernel/rcu/tree_plugin.h

+9 −9
Original line number Diff line number Diff line
@@ -1960,7 +1960,7 @@ static void wake_nocb_leader_defer(struct rcu_data *rdp, int waketype, 
 * Does the specified CPU need an RCU callback for the specified flavor

 * of rcu_barrier()?

 */

static bool rcu_nocb_cpu_needs_barrier(struct rcu_state *rsp, int cpu)

static bool rcu_nocb_cpu_needs_barrier(int cpu)

{

	struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);

	unsigned long ret;
@@ -2424,7 +2424,7 @@ void __init rcu_init_nohz(void) 
	for_each_rcu_flavor(rsp) {

		for_each_cpu(cpu, rcu_nocb_mask)

			init_nocb_callback_list(per_cpu_ptr(&rcu_data, cpu));

		rcu_organize_nocb_kthreads(rsp);

		rcu_organize_nocb_kthreads();

	}

}
@@ -2444,7 +2444,7 @@ static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp) 
 * brought online out of order, this can require re-organizing the

 * leader-follower relationships.

 */

static void rcu_spawn_one_nocb_kthread(struct rcu_state *rsp, int cpu)

static void rcu_spawn_one_nocb_kthread(int cpu)

{

	struct rcu_data *rdp;

	struct rcu_data *rdp_last;
@@ -2481,7 +2481,7 @@ static void rcu_spawn_one_nocb_kthread(struct rcu_state *rsp, int cpu) 


	/* Spawn the kthread for this CPU and RCU flavor. */

	t = kthread_run(rcu_nocb_kthread, rdp_spawn,

			"rcuo%c/%d", rsp->abbr, cpu);

			"rcuo%c/%d", rcu_state.abbr, cpu);

	BUG_ON(IS_ERR(t));

	WRITE_ONCE(rdp_spawn->nocb_kthread, t);

}
@@ -2496,7 +2496,7 @@ static void rcu_spawn_all_nocb_kthreads(int cpu) 


	if (rcu_scheduler_fully_active)

		for_each_rcu_flavor(rsp)

			rcu_spawn_one_nocb_kthread(rsp, cpu);

			rcu_spawn_one_nocb_kthread(cpu);

}



/*
@@ -2520,7 +2520,7 @@ module_param(rcu_nocb_leader_stride, int, 0444); 
/*

 * Initialize leader-follower relationships for all no-CBs CPU.

 */

static void __init rcu_organize_nocb_kthreads(struct rcu_state *rsp)

static void __init rcu_organize_nocb_kthreads(void)

{

	int cpu;

	int ls = rcu_nocb_leader_stride;
@@ -2579,7 +2579,7 @@ static bool init_nocb_callback_list(struct rcu_data *rdp) 


#else /* #ifdef CONFIG_RCU_NOCB_CPU */



static bool rcu_nocb_cpu_needs_barrier(struct rcu_state *rsp, int cpu)

static bool rcu_nocb_cpu_needs_barrier(int cpu)

{

	WARN_ON_ONCE(1); /* Should be dead code. */

	return false;
@@ -2648,12 +2648,12 @@ static bool init_nocb_callback_list(struct rcu_data *rdp) 
 * This code relies on the fact that all NO_HZ_FULL CPUs are also

 * CONFIG_RCU_NOCB_CPU CPUs.

 */

static bool rcu_nohz_full_cpu(struct rcu_state *rsp)

static bool rcu_nohz_full_cpu(void)

{

#ifdef CONFIG_NO_HZ_FULL

	if (tick_nohz_full_cpu(smp_processor_id()) &&

	    (!rcu_gp_in_progress() ||

	     ULONG_CMP_LT(jiffies, READ_ONCE(rsp->gp_start) + HZ)))

	     ULONG_CMP_LT(jiffies, READ_ONCE(rcu_state.gp_start) + HZ)))

		return true;

#endif /* #ifdef CONFIG_NO_HZ_FULL */

	return false;

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