Messages in this thread | | | Subject | Re: [PATCH v2 2/5] bpf: Add function map->ops->map_traverse_elem() to traverse map elems | From | Alexei Starovoitov <> | Date | Wed, 22 Jul 2015 18:00:22 -0700 |
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On 7/22/15 1:09 AM, Kaixu Xia wrote: > We want to traverse the map elements and make use > of the map value one by one. So add new function > map->ops->map_traverse_elem() to traverse map elements. ... > @@ -26,6 +28,7 @@ struct bpf_map_ops { > void *(*map_lookup_elem)(struct bpf_map *map, void *key); > int (*map_update_elem)(struct bpf_map *map, void *key, void *value, u64 flags); > int (*map_delete_elem)(struct bpf_map *map, void *key); > + int (*map_traverse_elem)(bpf_map_traverse_callback func, struct bpf_map *map);
I think 'traverse' is too error prone. Better to add 'map_delete_all_elem' callback. Then convert bpf_prog_array_map_clear() into such callback and similar callback from perf_event_array. Then call it with from bpf_map_release() and drop if (map->map_type == PROG_ARRAY) there. Just unconditionally map->ops->map_delete_all_elem(). Though looking at patch 3. I don't see why you need that. prog_array has to do it due to potential circular dependency between prog_fd of a program that uses a prog_array_fd and stores prog_fd inside that prog_array. In case of perf_event_array no such thing possible. Just release them as part of map_free.
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