rcu: Remove rsp parameter from rcu_node tree accessor macros

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 rcu_node
tree's accessor macros.  This commit therefore removes the rsp parameter
from those macros in kernel/rcu/rcu.h, and removes some now-unused rsp
local variables while in the area.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index 4d04683..2bb77fd 100644 (file)
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -329,29 +329,23 @@ static inline void rcu_init_levelspread(int *levelspread, const int *levelcnt)
 }
 
 /* Returns first leaf rcu_node of the specified RCU flavor. */
-#define rcu_first_leaf_node(rsp) ((rsp)->level[rcu_num_lvls - 1])
+#define rcu_first_leaf_node() (rcu_state.level[rcu_num_lvls - 1])
 
 /* Is this rcu_node a leaf? */
 #define rcu_is_leaf_node(rnp) ((rnp)->level == rcu_num_lvls - 1)
 
 /* Is this rcu_node the last leaf? */
-#define rcu_is_last_leaf_node(rsp, rnp) ((rnp) == &(rsp)->node[rcu_num_nodes - 1])
+#define rcu_is_last_leaf_node(rnp) ((rnp) == &rcu_state.node[rcu_num_nodes - 1])
 
 /*
- * Do a full breadth-first scan of the rcu_node structures for the
+ * Do a full breadth-first scan of the {s,}rcu_node structures for the
  * specified rcu_state structure.
  */
-#define rcu_for_each_node_breadth_first(rsp, rnp) \
-       for ((rnp) = &(rsp)->node[0]; \
-            (rnp) < &(rsp)->node[rcu_num_nodes]; (rnp)++)
-
-/*
- * Do a breadth-first scan of the non-leaf rcu_node structures for the
- * specified rcu_state structure.  Note that if there is a singleton
- * rcu_node tree with but one rcu_node structure, this loop is a no-op.
- */
-#define rcu_for_each_nonleaf_node_breadth_first(rsp, rnp) \
-       for ((rnp) = &(rsp)->node[0]; !rcu_is_leaf_node(rsp, rnp); (rnp)++)
+#define srcu_for_each_node_breadth_first(sp, rnp) \
+       for ((rnp) = &(sp)->node[0]; \
+            (rnp) < &(sp)->node[rcu_num_nodes]; (rnp)++)
+#define rcu_for_each_node_breadth_first(rnp) \
+       srcu_for_each_node_breadth_first(&rcu_state, rnp)
 
 /*
  * Scan the leaves of the rcu_node hierarchy for the specified rcu_state
@@ -359,9 +353,9 @@ static inline void rcu_init_levelspread(int *levelspread, const int *levelcnt)
  * one rcu_node structure, this loop -will- visit the rcu_node structure.
  * It is still a leaf node, even if it is also the root node.
  */
-#define rcu_for_each_leaf_node(rsp, rnp) \
-       for ((rnp) = rcu_first_leaf_node(rsp); \
-            (rnp) < &(rsp)->node[rcu_num_nodes]; (rnp)++)
+#define rcu_for_each_leaf_node(rnp) \
+       for ((rnp) = rcu_first_leaf_node(); \
+            (rnp) < &rcu_state.node[rcu_num_nodes]; (rnp)++)
 
 /*
  * Iterate over all possible CPUs in a leaf RCU node.

diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index 6c9866a..2042080 100644 (file)
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -105,7 +105,7 @@ static void init_srcu_struct_nodes(struct srcu_struct *sp, bool is_static)
        rcu_init_levelspread(levelspread, num_rcu_lvl);
 
        /* Each pass through this loop initializes one srcu_node structure. */
-       rcu_for_each_node_breadth_first(sp, snp) {
+       srcu_for_each_node_breadth_first(sp, snp) {
                spin_lock_init(&ACCESS_PRIVATE(snp, lock));
                WARN_ON_ONCE(ARRAY_SIZE(snp->srcu_have_cbs) !=
                             ARRAY_SIZE(snp->srcu_data_have_cbs));
@@ -561,7 +561,7 @@ static void srcu_gp_end(struct srcu_struct *sp)
 
        /* Initiate callback invocation as needed. */
        idx = rcu_seq_ctr(gpseq) % ARRAY_SIZE(snp->srcu_have_cbs);
-       rcu_for_each_node_breadth_first(sp, snp) {
+       srcu_for_each_node_breadth_first(sp, snp) {
                spin_lock_irq_rcu_node(snp);
                cbs = false;
                last_lvl = snp >= sp->level[rcu_num_lvls - 1];

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index e33bf2a..0465a85 100644 (file)
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -573,7 +573,7 @@ void show_rcu_gp_kthreads(void)
        for_each_rcu_flavor(rsp) {
                pr_info("%s: wait state: %d ->state: %#lx\n",
                        rsp->name, rsp->gp_state, rsp->gp_kthread->state);
-               rcu_for_each_node_breadth_first(rsp, rnp) {
+               rcu_for_each_node_breadth_first(rnp) {
                        if (ULONG_CMP_GE(rsp->gp_seq, rnp->gp_seq_needed))
                                continue;
                        pr_info("\trcu_node %d:%d ->gp_seq %lu ->gp_seq_needed %lu\n",
@@ -1276,7 +1276,7 @@ static void rcu_dump_cpu_stacks(void)
        unsigned long flags;
        struct rcu_node *rnp;
 
-       rcu_for_each_leaf_node(&rcu_state, rnp) {
+       rcu_for_each_leaf_node(rnp) {
                raw_spin_lock_irqsave_rcu_node(rnp, flags);
                for_each_leaf_node_possible_cpu(rnp, cpu)
                        if (rnp->qsmask & leaf_node_cpu_bit(rnp, cpu))
@@ -1336,7 +1336,7 @@ static void print_other_cpu_stall(unsigned long gp_seq)
         */
        pr_err("INFO: %s detected stalls on CPUs/tasks:", rsp->name);
        print_cpu_stall_info_begin();
-       rcu_for_each_leaf_node(rsp, rnp) {
+       rcu_for_each_leaf_node(rnp) {
                raw_spin_lock_irqsave_rcu_node(rnp, flags);
                ndetected += rcu_print_task_stall(rnp);
                if (rnp->qsmask != 0) {
@@ -1873,7 +1873,7 @@ static bool rcu_gp_init(void)
         * will handle subsequent offline CPUs.
         */
        rsp->gp_state = RCU_GP_ONOFF;
-       rcu_for_each_leaf_node(rsp, rnp) {
+       rcu_for_each_leaf_node(rnp) {
                spin_lock(&rsp->ofl_lock);
                raw_spin_lock_irq_rcu_node(rnp);
                if (rnp->qsmaskinit == rnp->qsmaskinitnext &&
@@ -1933,7 +1933,7 @@ static bool rcu_gp_init(void)
         * process finishes, because this kthread handles both.
         */
        rsp->gp_state = RCU_GP_INIT;
-       rcu_for_each_node_breadth_first(rsp, rnp) {
+       rcu_for_each_node_breadth_first(rnp) {
                rcu_gp_slow(gp_init_delay);
                raw_spin_lock_irqsave_rcu_node(rnp, flags);
                rdp = this_cpu_ptr(&rcu_data);
@@ -2046,7 +2046,7 @@ static void rcu_gp_cleanup(void)
         */
        new_gp_seq = rsp->gp_seq;
        rcu_seq_end(&new_gp_seq);
-       rcu_for_each_node_breadth_first(rsp, rnp) {
+       rcu_for_each_node_breadth_first(rnp) {
                raw_spin_lock_irq_rcu_node(rnp);
                if (WARN_ON_ONCE(rcu_preempt_blocked_readers_cgp(rnp)))
                        dump_blkd_tasks(rnp, 10);
@@ -2606,9 +2606,8 @@ static void force_qs_rnp(int (*f)(struct rcu_data *rsp))
        unsigned long flags;
        unsigned long mask;
        struct rcu_node *rnp;
-       struct rcu_state *rsp = &rcu_state;
 
-       rcu_for_each_leaf_node(rsp, rnp) {
+       rcu_for_each_leaf_node(rnp) {
                cond_resched_tasks_rcu_qs();
                mask = 0;
                raw_spin_lock_irqsave_rcu_node(rnp, flags);
@@ -3778,7 +3777,7 @@ static void __init rcu_init_one(void)
 
        init_swait_queue_head(&rsp->gp_wq);
        init_swait_queue_head(&rsp->expedited_wq);
-       rnp = rcu_first_leaf_node(rsp);
+       rnp = rcu_first_leaf_node();
        for_each_possible_cpu(i) {
                while (i > rnp->grphi)
                        rnp++;
@@ -3878,7 +3877,7 @@ static void __init rcu_dump_rcu_node_tree(void)
 
        pr_info("rcu_node tree layout dump\n");
        pr_info(" ");
-       rcu_for_each_node_breadth_first(&rcu_state, rnp) {
+       rcu_for_each_node_breadth_first(rnp) {
                if (rnp->level != level) {
                        pr_cont("\n");
                        pr_info(" ");

diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index b6f7bc3..060bdb4 100644 (file)
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -97,7 +97,7 @@ static void sync_exp_reset_tree_hotplug(void)
         * Each pass through the following loop propagates newly onlined
         * CPUs for the current rcu_node structure up the rcu_node tree.
         */
-       rcu_for_each_leaf_node(&rcu_state, rnp) {
+       rcu_for_each_leaf_node(rnp) {
                raw_spin_lock_irqsave_rcu_node(rnp, flags);
                if (rnp->expmaskinit == rnp->expmaskinitnext) {
                        raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
@@ -141,7 +141,7 @@ static void __maybe_unused sync_exp_reset_tree(void)
        struct rcu_node *rnp;
 
        sync_exp_reset_tree_hotplug();
-       rcu_for_each_node_breadth_first(&rcu_state, rnp) {
+       rcu_for_each_node_breadth_first(rnp) {
                raw_spin_lock_irqsave_rcu_node(rnp, flags);
                WARN_ON_ONCE(rnp->expmask);
                rnp->expmask = rnp->expmaskinit;
@@ -438,14 +438,14 @@ static void sync_rcu_exp_select_cpus(smp_call_func_t func)
        trace_rcu_exp_grace_period(rcu_state.name, rcu_exp_gp_seq_endval(), TPS("select"));
 
        /* Schedule work for each leaf rcu_node structure. */
-       rcu_for_each_leaf_node(&rcu_state, rnp) {
+       rcu_for_each_leaf_node(rnp) {
                rnp->exp_need_flush = false;
                if (!READ_ONCE(rnp->expmask))
                        continue; /* Avoid early boot non-existent wq. */
                rnp->rew.rew_func = func;
                if (!READ_ONCE(rcu_par_gp_wq) ||
                    rcu_scheduler_active != RCU_SCHEDULER_RUNNING ||
-                   rcu_is_last_leaf_node(&rcu_state, rnp)) {
+                   rcu_is_last_leaf_node(rnp)) {
                        /* No workqueues yet or last leaf, do direct call. */
                        sync_rcu_exp_select_node_cpus(&rnp->rew.rew_work);
                        continue;
@@ -462,7 +462,7 @@ static void sync_rcu_exp_select_cpus(smp_call_func_t func)
        }
 
        /* Wait for workqueue jobs (if any) to complete. */
-       rcu_for_each_leaf_node(&rcu_state, rnp)
+       rcu_for_each_leaf_node(rnp)
                if (rnp->exp_need_flush)
                        flush_work(&rnp->rew.rew_work);
 }
@@ -496,7 +496,7 @@ static void synchronize_sched_expedited_wait(void)
                pr_err("INFO: %s detected expedited stalls on CPUs/tasks: {",
                       rcu_state.name);
                ndetected = 0;
-               rcu_for_each_leaf_node(&rcu_state, rnp) {
+               rcu_for_each_leaf_node(rnp) {
                        ndetected += rcu_print_task_exp_stall(rnp);
                        for_each_leaf_node_possible_cpu(rnp, cpu) {
                                struct rcu_data *rdp;
@@ -517,7 +517,7 @@ static void synchronize_sched_expedited_wait(void)
                        rnp_root->expmask, ".T"[!!rnp_root->exp_tasks]);
                if (ndetected) {
                        pr_err("blocking rcu_node structures:");
-                       rcu_for_each_node_breadth_first(&rcu_state, rnp) {
+                       rcu_for_each_node_breadth_first(rnp) {
                                if (rnp == rnp_root)
                                        continue; /* printed unconditionally */
                                if (sync_rcu_preempt_exp_done_unlocked(rnp))
@@ -529,7 +529,7 @@ static void synchronize_sched_expedited_wait(void)
                        }
                        pr_cont("\n");
                }
-               rcu_for_each_leaf_node(&rcu_state, rnp) {
+               rcu_for_each_leaf_node(rnp) {
                        for_each_leaf_node_possible_cpu(rnp, cpu) {
                                mask = leaf_node_cpu_bit(rnp, cpu);
                                if (!(rnp->expmask & mask))
@@ -561,7 +561,7 @@ static void rcu_exp_wait_wake(unsigned long s)
         */
        mutex_lock(&rcu_state.exp_wake_mutex);
 
-       rcu_for_each_node_breadth_first(&rcu_state, rnp) {
+       rcu_for_each_node_breadth_first(rnp) {
                if (ULONG_CMP_LT(READ_ONCE(rnp->exp_seq_rq), s)) {
                        spin_lock(&rnp->exp_lock);
                        /* Recheck, avoid hang in case someone just arrived. */

diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index e6ec25e..b60d3df 100644 (file)
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -687,7 +687,7 @@ static void rcu_print_detail_task_stall(void)
        struct rcu_node *rnp = rcu_get_root();
 
        rcu_print_detail_task_stall_rnp(rnp);
-       rcu_for_each_leaf_node(&rcu_state, rnp)
+       rcu_for_each_leaf_node(rnp)
                rcu_print_detail_task_stall_rnp(rnp);
 }
 
@@ -1427,7 +1427,7 @@ static void __init rcu_spawn_boost_kthreads(void)
        for_each_possible_cpu(cpu)
                per_cpu(rcu_cpu_has_work, cpu) = 0;
        BUG_ON(smpboot_register_percpu_thread(&rcu_cpu_thread_spec));
-       rcu_for_each_leaf_node(&rcu_state, rnp)
+       rcu_for_each_leaf_node(rnp)
                (void)rcu_spawn_one_boost_kthread(rnp);
 }