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-rw-r--r--kernel/rcu/tree.c21
-rw-r--r--kernel/rcu/tree.h15
-rw-r--r--kernel/rcu/tree_exp.h16
-rw-r--r--kernel/rcu/tree_plugin.h5
4 files changed, 34 insertions, 23 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index e5ca15a461b9..f433959e9322 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1287,9 +1287,9 @@ static void rcu_dump_cpu_stacks(struct rcu_state *rsp)
rcu_for_each_leaf_node(rsp, rnp) {
raw_spin_lock_irqsave_rcu_node(rnp, flags);
if (rnp->qsmask != 0) {
- for (cpu = 0; cpu <= rnp->grphi - rnp->grplo; cpu++)
- if (rnp->qsmask & (1UL << cpu))
- dump_cpu_task(rnp->grplo + cpu);
+ for_each_leaf_node_possible_cpu(rnp, cpu)
+ if (rnp->qsmask & leaf_node_cpu_bit(rnp, cpu))
+ dump_cpu_task(cpu);
}
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
@@ -1360,10 +1360,9 @@ static void print_other_cpu_stall(struct rcu_state *rsp, unsigned long gpnum)
raw_spin_lock_irqsave_rcu_node(rnp, flags);
ndetected += rcu_print_task_stall(rnp);
if (rnp->qsmask != 0) {
- for (cpu = 0; cpu <= rnp->grphi - rnp->grplo; cpu++)
- if (rnp->qsmask & (1UL << cpu)) {
- print_cpu_stall_info(rsp,
- rnp->grplo + cpu);
+ for_each_leaf_node_possible_cpu(rnp, cpu)
+ if (rnp->qsmask & leaf_node_cpu_bit(rnp, cpu)) {
+ print_cpu_stall_info(rsp, cpu);
ndetected++;
}
}
@@ -2884,7 +2883,6 @@ static void force_qs_rnp(struct rcu_state *rsp,
unsigned long *maxj),
bool *isidle, unsigned long *maxj)
{
- unsigned long bit;
int cpu;
unsigned long flags;
unsigned long mask;
@@ -2919,9 +2917,8 @@ static void force_qs_rnp(struct rcu_state *rsp,
continue;
}
}
- cpu = rnp->grplo;
- bit = 1;
- for (; cpu <= rnp->grphi; cpu++, bit <<= 1) {
+ for_each_leaf_node_possible_cpu(rnp, cpu) {
+ unsigned long bit = leaf_node_cpu_bit(rnp, cpu);
if ((rnp->qsmask & bit) != 0) {
if (f(per_cpu_ptr(rsp->rda, cpu), isidle, maxj))
mask |= bit;
@@ -3750,7 +3747,7 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
/* Set up local state, ensuring consistent view of global state. */
raw_spin_lock_irqsave_rcu_node(rnp, flags);
- rdp->grpmask = 1UL << (cpu - rdp->mynode->grplo);
+ rdp->grpmask = leaf_node_cpu_bit(rdp->mynode, cpu);
rdp->dynticks = &per_cpu(rcu_dynticks, cpu);
WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != DYNTICK_TASK_EXIT_IDLE);
WARN_ON_ONCE(atomic_read(&rdp->dynticks->dynticks) != 1);
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index e3959f5e6ddf..f714f873bf9d 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -254,6 +254,13 @@ struct rcu_node {
} ____cacheline_internodealigned_in_smp;
/*
+ * Bitmasks in an rcu_node cover the interval [grplo, grphi] of CPU IDs, and
+ * are indexed relative to this interval rather than the global CPU ID space.
+ * This generates the bit for a CPU in node-local masks.
+ */
+#define leaf_node_cpu_bit(rnp, cpu) (1UL << ((cpu) - (rnp)->grplo))
+
+/*
* Do a full breadth-first scan of the rcu_node structures for the
* specified rcu_state structure.
*/
@@ -281,6 +288,14 @@ struct rcu_node {
(rnp) < &(rsp)->node[rcu_num_nodes]; (rnp)++)
/*
+ * Iterate over all possible CPUs in a leaf RCU node.
+ */
+#define for_each_leaf_node_possible_cpu(rnp, cpu) \
+ for ((cpu) = cpumask_next(rnp->grplo - 1, cpu_possible_mask); \
+ cpu <= rnp->grphi; \
+ cpu = cpumask_next((cpu), cpu_possible_mask))
+
+/*
* Union to allow "aggregate OR" operation on the need for a quiescent
* state by the normal and expedited grace periods.
*/
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index 00a02a231ada..d400434af6b2 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -344,7 +344,6 @@ static void sync_rcu_exp_select_cpus(struct rcu_state *rsp,
{
int cpu;
unsigned long flags;
- unsigned long mask;
unsigned long mask_ofl_test;
unsigned long mask_ofl_ipi;
int ret;
@@ -356,7 +355,7 @@ static void sync_rcu_exp_select_cpus(struct rcu_state *rsp,
/* Each pass checks a CPU for identity, offline, and idle. */
mask_ofl_test = 0;
- for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++) {
+ for_each_leaf_node_possible_cpu(rnp, cpu) {
struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu);
@@ -376,8 +375,8 @@ static void sync_rcu_exp_select_cpus(struct rcu_state *rsp,
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
/* IPI the remaining CPUs for expedited quiescent state. */
- mask = 1;
- for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++, mask <<= 1) {
+ for_each_leaf_node_possible_cpu(rnp, cpu) {
+ unsigned long mask = leaf_node_cpu_bit(rnp, cpu);
if (!(mask_ofl_ipi & mask))
continue;
retry_ipi:
@@ -440,10 +439,10 @@ static void synchronize_sched_expedited_wait(struct rcu_state *rsp)
ndetected = 0;
rcu_for_each_leaf_node(rsp, rnp) {
ndetected += rcu_print_task_exp_stall(rnp);
- mask = 1;
- for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++, mask <<= 1) {
+ for_each_leaf_node_possible_cpu(rnp, cpu) {
struct rcu_data *rdp;
+ mask = leaf_node_cpu_bit(rnp, cpu);
if (!(rnp->expmask & mask))
continue;
ndetected++;
@@ -453,7 +452,6 @@ static void synchronize_sched_expedited_wait(struct rcu_state *rsp)
"o."[!!(rdp->grpmask & rnp->expmaskinit)],
"N."[!!(rdp->grpmask & rnp->expmaskinitnext)]);
}
- mask <<= 1;
}
pr_cont(" } %lu jiffies s: %lu root: %#lx/%c\n",
jiffies - jiffies_start, rsp->expedited_sequence,
@@ -473,8 +471,8 @@ static void synchronize_sched_expedited_wait(struct rcu_state *rsp)
pr_cont("\n");
}
rcu_for_each_leaf_node(rsp, rnp) {
- mask = 1;
- for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++, mask <<= 1) {
+ for_each_leaf_node_possible_cpu(rnp, cpu) {
+ mask = leaf_node_cpu_bit(rnp, cpu);
if (!(rnp->expmask & mask))
continue;
dump_cpu_task(cpu);
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 695071dd1e9c..534c590e8852 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -1166,8 +1166,9 @@ static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu)
return;
if (!zalloc_cpumask_var(&cm, GFP_KERNEL))
return;
- for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++, mask >>= 1)
- if ((mask & 0x1) && cpu != outgoingcpu)
+ for_each_leaf_node_possible_cpu(rnp, cpu)
+ if ((mask & leaf_node_cpu_bit(rnp, cpu)) &&
+ cpu != outgoingcpu)
cpumask_set_cpu(cpu, cm);
if (cpumask_weight(cm) == 0)
cpumask_setall(cm);
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-18 02:42:58 +0000