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From:   Song Liu <song@kernel.org>
Date:   Mon, 27 Jul 2020 22:31:04 -0700
Message-ID: <CAPhsuW5EVOgL4Xhb1LDcF8EH4hUqY=-rFBRRnuGMSRfoviZnMA@mail.gmail.com>
Subject: Re: [PATCH bpf-next v2 16/35] bpf: eliminate rlimit-based memory
 accounting for cgroup storage maps
To:     Roman Gushchin <guro@fb.com>
Cc:     bpf <bpf@vger.kernel.org>, Networking <netdev@vger.kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Kernel Team <kernel-team@fb.com>,
        open list <linux-kernel@vger.kernel.org>
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Sender: linux-kernel-owner@vger.kernel.org
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On Mon, Jul 27, 2020 at 12:21 PM Roman Gushchin <guro@fb.com> wrote:
>
> Do not use rlimit-based memory accounting for cgroup storage maps.
> It has been replaced with the memcg-based memory accounting.
>
> Signed-off-by: Roman Gushchin <guro@fb.com>

Acked-by: Song Liu <songliubraving@fb.com>

> ---
>  kernel/bpf/local_storage.c | 21 +--------------------
>  1 file changed, 1 insertion(+), 20 deletions(-)
>
> diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c
> index 117acb2e80fb..5f29a420849c 100644
> --- a/kernel/bpf/local_storage.c
> +++ b/kernel/bpf/local_storage.c
> @@ -288,8 +288,6 @@ static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
>  {
>         int numa_node = bpf_map_attr_numa_node(attr);
>         struct bpf_cgroup_storage_map *map;
> -       struct bpf_map_memory mem;
> -       int ret;
>
>         if (attr->key_size != sizeof(struct bpf_cgroup_storage_key) &&
>             attr->key_size != sizeof(__u64))
> @@ -309,18 +307,10 @@ static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
>                 /* max_entries is not used and enforced to be 0 */
>                 return ERR_PTR(-EINVAL);
>
> -       ret = bpf_map_charge_init(&mem, sizeof(struct bpf_cgroup_storage_map));
> -       if (ret < 0)
> -               return ERR_PTR(ret);
> -
>         map = kmalloc_node(sizeof(struct bpf_cgroup_storage_map),
>                            __GFP_ZERO | GFP_USER | __GFP_ACCOUNT, numa_node);
> -       if (!map) {
> -               bpf_map_charge_finish(&mem);
> +       if (!map)
>                 return ERR_PTR(-ENOMEM);
> -       }
> -
> -       bpf_map_charge_move(&map->map.memory, &mem);
>
>         /* copy mandatory map attributes */
>         bpf_map_init_from_attr(&map->map, attr);
> @@ -509,9 +499,6 @@ struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(struct bpf_prog *prog,
>
>         size = bpf_cgroup_storage_calculate_size(map, &pages);
>
> -       if (bpf_map_charge_memlock(map, pages))
> -               return ERR_PTR(-EPERM);
> -
>         storage = kmalloc_node(sizeof(struct bpf_cgroup_storage), gfp,
>                                map->numa_node);
>         if (!storage)
> @@ -533,7 +520,6 @@ struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(struct bpf_prog *prog,
>         return storage;
>
>  enomem:
> -       bpf_map_uncharge_memlock(map, pages);
>         kfree(storage);
>         return ERR_PTR(-ENOMEM);
>  }
> @@ -560,16 +546,11 @@ void bpf_cgroup_storage_free(struct bpf_cgroup_storage *storage)
>  {
>         enum bpf_cgroup_storage_type stype;
>         struct bpf_map *map;
> -       u32 pages;
>
>         if (!storage)
>                 return;
>
>         map = &storage->map->map;
> -
> -       bpf_cgroup_storage_calculate_size(map, &pages);
> -       bpf_map_uncharge_memlock(map, pages);
> -
>         stype = cgroup_storage_type(map);
>         if (stype == BPF_CGROUP_STORAGE_SHARED)
>                 call_rcu(&storage->rcu, free_shared_cgroup_storage_rcu);
> --
> 2.26.2
>