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From:   Song Liu <song@kernel.org>
Date:   Mon, 27 Jul 2020 22:30:35 -0700
Message-ID: <CAPhsuW4-ubo3iz=-0=yQOEkQKFVpkChycUwGBV-gdsgoAOybnw@mail.gmail.com>
Subject: Re: [PATCH bpf-next v2 15/35] bpf: eliminate rlimit-based memory
 accounting for cpumap 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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On Mon, Jul 27, 2020 at 12:22 PM Roman Gushchin <guro@fb.com> wrote:
>
> Do not use rlimit-based memory accounting for cpumap 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/cpumap.c | 16 +---------------
>  1 file changed, 1 insertion(+), 15 deletions(-)
>
> diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
> index 74ae9fcbe82e..50f3444a3301 100644
> --- a/kernel/bpf/cpumap.c
> +++ b/kernel/bpf/cpumap.c
> @@ -86,8 +86,6 @@ static struct bpf_map *cpu_map_alloc(union bpf_attr *attr)
>         u32 value_size = attr->value_size;
>         struct bpf_cpu_map *cmap;
>         int err = -ENOMEM;
> -       u64 cost;
> -       int ret;
>
>         if (!bpf_capable())
>                 return ERR_PTR(-EPERM);
> @@ -111,26 +109,14 @@ static struct bpf_map *cpu_map_alloc(union bpf_attr *attr)
>                 goto free_cmap;
>         }
>
> -       /* make sure page count doesn't overflow */
> -       cost = (u64) cmap->map.max_entries * sizeof(struct bpf_cpu_map_entry *);
> -
> -       /* Notice returns -EPERM on if map size is larger than memlock limit */
> -       ret = bpf_map_charge_init(&cmap->map.memory, cost);
> -       if (ret) {
> -               err = ret;
> -               goto free_cmap;
> -       }
> -
>         /* Alloc array for possible remote "destination" CPUs */
>         cmap->cpu_map = bpf_map_area_alloc(cmap->map.max_entries *
>                                            sizeof(struct bpf_cpu_map_entry *),
>                                            cmap->map.numa_node);
>         if (!cmap->cpu_map)
> -               goto free_charge;
> +               goto free_cmap;
>
>         return &cmap->map;
> -free_charge:
> -       bpf_map_charge_finish(&cmap->map.memory);
>  free_cmap:
>         kfree(cmap);
>         return ERR_PTR(err);
> --
> 2.26.2
>