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Diffstat (limited to 'kernel/bpf/percpu_freelist.c')
-rw-r--r--kernel/bpf/percpu_freelist.c101
1 files changed, 96 insertions, 5 deletions
diff --git a/kernel/bpf/percpu_freelist.c b/kernel/bpf/percpu_freelist.c
index b367430e611c..3d897de89061 100644
--- a/kernel/bpf/percpu_freelist.c
+++ b/kernel/bpf/percpu_freelist.c
@@ -17,6 +17,8 @@ int pcpu_freelist_init(struct pcpu_freelist *s)
raw_spin_lock_init(&head->lock);
head->first = NULL;
}
+ raw_spin_lock_init(&s->extralist.lock);
+ s->extralist.first = NULL;
return 0;
}
@@ -40,12 +42,50 @@ static inline void ___pcpu_freelist_push(struct pcpu_freelist_head *head,
raw_spin_unlock(&head->lock);
}
+static inline bool pcpu_freelist_try_push_extra(struct pcpu_freelist *s,
+ struct pcpu_freelist_node *node)
+{
+ if (!raw_spin_trylock(&s->extralist.lock))
+ return false;
+
+ pcpu_freelist_push_node(&s->extralist, node);
+ raw_spin_unlock(&s->extralist.lock);
+ return true;
+}
+
+static inline void ___pcpu_freelist_push_nmi(struct pcpu_freelist *s,
+ struct pcpu_freelist_node *node)
+{
+ int cpu, orig_cpu;
+
+ orig_cpu = cpu = raw_smp_processor_id();
+ while (1) {
+ struct pcpu_freelist_head *head;
+
+ head = per_cpu_ptr(s->freelist, cpu);
+ if (raw_spin_trylock(&head->lock)) {
+ pcpu_freelist_push_node(head, node);
+ raw_spin_unlock(&head->lock);
+ return;
+ }
+ cpu = cpumask_next(cpu, cpu_possible_mask);
+ if (cpu >= nr_cpu_ids)
+ cpu = 0;
+
+ /* cannot lock any per cpu lock, try extralist */
+ if (cpu == orig_cpu &&
+ pcpu_freelist_try_push_extra(s, node))
+ return;
+ }
+}
+
void __pcpu_freelist_push(struct pcpu_freelist *s,
struct pcpu_freelist_node *node)
{
- struct pcpu_freelist_head *head = this_cpu_ptr(s->freelist);
-
- ___pcpu_freelist_push(head, node);
+ if (in_nmi())
+ ___pcpu_freelist_push_nmi(s, node);
+ else
+ ___pcpu_freelist_push(this_cpu_ptr(s->freelist), node);
}
void pcpu_freelist_push(struct pcpu_freelist *s,
@@ -81,7 +121,7 @@ again:
}
}
-struct pcpu_freelist_node *__pcpu_freelist_pop(struct pcpu_freelist *s)
+static struct pcpu_freelist_node *___pcpu_freelist_pop(struct pcpu_freelist *s)
{
struct pcpu_freelist_head *head;
struct pcpu_freelist_node *node;
@@ -102,8 +142,59 @@ struct pcpu_freelist_node *__pcpu_freelist_pop(struct pcpu_freelist *s)
if (cpu >= nr_cpu_ids)
cpu = 0;
if (cpu == orig_cpu)
- return NULL;
+ break;
+ }
+
+ /* per cpu lists are all empty, try extralist */
+ raw_spin_lock(&s->extralist.lock);
+ node = s->extralist.first;
+ if (node)
+ s->extralist.first = node->next;
+ raw_spin_unlock(&s->extralist.lock);
+ return node;
+}
+
+static struct pcpu_freelist_node *
+___pcpu_freelist_pop_nmi(struct pcpu_freelist *s)
+{
+ struct pcpu_freelist_head *head;
+ struct pcpu_freelist_node *node;
+ int orig_cpu, cpu;
+
+ orig_cpu = cpu = raw_smp_processor_id();
+ while (1) {
+ head = per_cpu_ptr(s->freelist, cpu);
+ if (raw_spin_trylock(&head->lock)) {
+ node = head->first;
+ if (node) {
+ head->first = node->next;
+ raw_spin_unlock(&head->lock);
+ return node;
+ }
+ raw_spin_unlock(&head->lock);
+ }
+ cpu = cpumask_next(cpu, cpu_possible_mask);
+ if (cpu >= nr_cpu_ids)
+ cpu = 0;
+ if (cpu == orig_cpu)
+ break;
}
+
+ /* cannot pop from per cpu lists, try extralist */
+ if (!raw_spin_trylock(&s->extralist.lock))
+ return NULL;
+ node = s->extralist.first;
+ if (node)
+ s->extralist.first = node->next;
+ raw_spin_unlock(&s->extralist.lock);
+ return node;
+}
+
+struct pcpu_freelist_node *__pcpu_freelist_pop(struct pcpu_freelist *s)
+{
+ if (in_nmi())
+ return ___pcpu_freelist_pop_nmi(s);
+ return ___pcpu_freelist_pop(s);
}
struct pcpu_freelist_node *pcpu_freelist_pop(struct pcpu_freelist *s)