On Thu, 2024-02-08 at 20:06 -0800, Alexei Starovoitov wrote:
[...]
> @@ -9830,8 +9861,8 @@ int bpf_map__set_value_size(struct bpf_map *map, __u32 size)
> int err;
> size_t mmap_old_sz, mmap_new_sz;
>
> - mmap_old_sz = bpf_map_mmap_sz(map->def.value_size, map->def.max_entries);
> - mmap_new_sz = bpf_map_mmap_sz(size, map->def.max_entries);
> + mmap_old_sz = bpf_map_mmap_sz(map);
> + mmap_new_sz = __bpf_map_mmap_sz(size, map->def.max_entries);
> err = bpf_map_mmap_resize(map, mmap_old_sz, mmap_new_sz);
> if (err) {
> pr_warn("map '%s': failed to resize memory-mapped region: %d\n",
I think that as is bpf_map__set_value_size() won't work for arenas.
The bpf_map_mmap_resize() does the following:
static int bpf_map_mmap_resize(struct bpf_map *map, size_t old_sz, size_t new_sz)
{
...
mmaped = mmap(NULL, new_sz, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
...
memcpy(mmaped, map->mmaped, min(old_sz, new_sz));
munmap(map->mmaped, old_sz);
map->mmaped = mmaped;
...
}
Which does not seem to tie the new mapping to arena, or am I missing something?
