| Message ID | 157324879178.910124.2574532467255490597.stgit@toke.dk |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | libbpf: Fix pinning and error message bugs and add new getters | expand |
From: Toke Høiland-Jørgensen <toke@redhat.com> Date: Fri, 08 Nov 2019 22:33:11 +0100 > 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> Acked-by: David S. Miller <davem@davemloft.net>
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(+) > [...]
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 582c0fd16697..facd5e1a3a0b 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4790,6 +4790,11 @@ int bpf_program__fd(const struct bpf_program *prog) return bpf_program__nth_fd(prog, 0); } +size_t bpf_program__size(const struct bpf_program *prog) +{ + return prog->insns_cnt * sizeof(struct bpf_insn); +} + int bpf_program__set_prep(struct bpf_program *prog, int nr_instances, bpf_program_prep_t prep) { diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index f0947cc949d2..10875dc68ec8 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -213,6 +213,7 @@ LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog, LIBBPF_API const char *bpf_program__title(const struct bpf_program *prog, bool needs_copy); +LIBBPF_API size_t bpf_program__size(const struct bpf_program *prog); LIBBPF_API int bpf_program__load(struct bpf_program *prog, char *license, __u32 kern_version); diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index d1a782a3a58d..9f39ee06b2d4 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -203,4 +203,5 @@ LIBBPF_0.0.6 { bpf_program__get_type; bpf_program__is_tracing; bpf_program__set_tracing; + bpf_program__size; } LIBBPF_0.0.5;