From: Andrii Nakryiko <andrii.nakryiko@gmail.com>
To: "Toke Høiland-Jørgensen" <toke@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>,
Alexei Starovoitov <ast@kernel.org>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>,
Jesper Dangaard Brouer <brouer@redhat.com>,
David Miller <davem@davemloft.net>,
Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>
Subject: Re: [PATCH bpf-next v2 6/6] libbpf: Add getter for program size
Date: Fri, 8 Nov 2019 15:16:45 -0800 [thread overview]
Message-ID: <CAEf4BzZAfXjh+QdaRPHyNJKiW3PzL8UF38_-AridYdM7Bg54_Q@mail.gmail.com> (raw)
In-Reply-To: <157324879178.910124.2574532467255490597.stgit@toke.dk>
On Fri, Nov 8, 2019 at 1:33 PM Toke Høiland-Jørgensen <toke@redhat.com> wrote:
>
> From: Toke Høiland-Jørgensen <toke@redhat.com>
>
> This adds a new getter for the BPF program size (in bytes). This is useful
> for a caller that is trying to predict how much memory will be locked by
> loading a BPF object into the kernel.
>
> Acked-by: Song Liu <songliubraving@fb.com>
> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
> ---
Can you add comment mentioning that this is size in bytes, not in
number of instructions? It's certainly will be a first question anyone
using this will ask.
I think it's good to have this, but I don't think you can really
predict how much memory will be used. I'd expect memory used by maps
(and not just based on element size and count, but some internal
bookkeeping stuff) would be much bigger factor and not easy to guess.
So beyond just stats dumping, I think this won't be that helpful.
Acked-by: Andrii Nakryiko <andriin@fb.com>
> tools/lib/bpf/libbpf.c | 5 +++++
> tools/lib/bpf/libbpf.h | 1 +
> tools/lib/bpf/libbpf.map | 1 +
> 3 files changed, 7 insertions(+)
>
[...]
prev parent reply other threads:[~2019-11-08 23:16 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-08 21:33 [PATCH bpf-next v2 0/6] libbpf: Fix pinning and error message bugs and add new getters Toke Høiland-Jørgensen
2019-11-08 21:33 ` [PATCH bpf-next v2 1/6] libbpf: Unpin auto-pinned maps if loading fails Toke Høiland-Jørgensen
2019-11-08 21:41 ` David Miller
2019-11-08 22:40 ` Andrii Nakryiko
2019-11-08 23:33 ` Toke Høiland-Jørgensen
2019-11-08 23:35 ` Andrii Nakryiko
2019-11-08 21:33 ` [PATCH bpf-next v2 2/6] selftests/bpf: Add tests for automatic map unpinning on load failure Toke Høiland-Jørgensen
2019-11-08 21:41 ` David Miller
2019-11-08 22:00 ` Song Liu
2019-11-08 22:43 ` Andrii Nakryiko
2019-11-08 21:33 ` [PATCH bpf-next v2 3/6] libbpf: Propagate EPERM to caller on program load Toke Høiland-Jørgensen
2019-11-08 21:43 ` David Miller
2019-11-08 22:50 ` Andrii Nakryiko
2019-11-08 23:17 ` Alexei Starovoitov
2019-11-08 23:32 ` Toke Høiland-Jørgensen
2019-11-08 21:33 ` [PATCH bpf-next v2 4/6] libbpf: Use pr_warn() when printing netlink errors Toke Høiland-Jørgensen
2019-11-08 21:43 ` David Miller
2019-11-08 22:52 ` Andrii Nakryiko
2019-11-08 21:33 ` [PATCH bpf-next v2 5/6] libbpf: Add bpf_get_link_xdp_info() function to get more XDP information Toke Høiland-Jørgensen
2019-11-08 21:43 ` David Miller
2019-11-08 23:10 ` Andrii Nakryiko
2019-11-08 21:33 ` [PATCH bpf-next v2 6/6] libbpf: Add getter for program size Toke Høiland-Jørgensen
2019-11-08 21:43 ` David Miller
2019-11-08 23:16 ` Andrii Nakryiko [this message]
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