diff options
| -rw-r--r-- | include/linux/list.h | 14 | ||||
| -rw-r--r-- | kernel/bpf/xskmap.c | 3 |
2 files changed, 15 insertions, 2 deletions
diff --git a/include/linux/list.h b/include/linux/list.h index e951228db4b2..85c92555e31f 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -106,6 +106,20 @@ static inline void __list_del(struct list_head * prev, struct list_head * next) WRITE_ONCE(prev->next, next); } +/* + * Delete a list entry and clear the 'prev' pointer. + * + * This is a special-purpose list clearing method used in the networking code + * for lists allocated as per-cpu, where we don't want to incur the extra + * WRITE_ONCE() overhead of a regular list_del_init(). The code that uses this + * needs to check the node 'prev' pointer instead of calling list_empty(). + */ +static inline void __list_del_clearprev(struct list_head *entry) +{ + __list_del(entry->prev, entry->next); + entry->prev = NULL; +} + /** * list_del - deletes entry from list. * @entry: the element to delete from the list. diff --git a/kernel/bpf/xskmap.c b/kernel/bpf/xskmap.c index ef7338cebd18..9bb96ace9fa1 100644 --- a/kernel/bpf/xskmap.c +++ b/kernel/bpf/xskmap.c @@ -145,8 +145,7 @@ void __xsk_map_flush(struct bpf_map *map) list_for_each_entry_safe(xs, tmp, flush_list, flush_node) { xsk_flush(xs); - __list_del(xs->flush_node.prev, xs->flush_node.next); - xs->flush_node.prev = NULL; + __list_del_clearprev(&xs->flush_node); } } |