On Mon, Jul 7, 2025 at 9:04 AM Leon Hwang <leon.hwang@xxxxxxxxx> wrote:
>
> This patch adds libbpf support for the BPF_F_CPU flag in percpu_array maps,
> introducing the following APIs:
>
> 1. bpf_map_update_elem_opts(): update with struct bpf_map_update_elem_opts
> 2. bpf_map_lookup_elem_opts(): lookup with struct bpf_map_lookup_elem_opts
> 3. bpf_map__update_elem_opts(): high-level wrapper with input validation
> 4. bpf_map__lookup_elem_opts(): high-level wrapper with input validation
>
> Behavior:
>
> * If opts->cpu == (u32)~0, the update is applied to all CPUs.
> * Otherwise, it applies only to the specified CPU.
> * Lookup APIs retrieve values from the target CPU when BPF_F_CPU is used.
>
> Signed-off-by: Leon Hwang <leon.hwang@xxxxxxxxx>
> ---
> tools/lib/bpf/bpf.c | 23 ++++++++++++++
> tools/lib/bpf/bpf.h | 36 +++++++++++++++++++++-
> tools/lib/bpf/libbpf.c | 56 +++++++++++++++++++++++++++++++----
> tools/lib/bpf/libbpf.h | 53 ++++++++++++++++++++++++++++-----
> tools/lib/bpf/libbpf.map | 4 +++
> tools/lib/bpf/libbpf_common.h | 14 +++++++++
> 6 files changed, 172 insertions(+), 14 deletions(-)
>
LGTM, just see the note about libpbf.map file, thanks.
> diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
> index 1bbf77326420..d21288991d1c 100644
> --- a/tools/lib/bpf/libbpf.map
> +++ b/tools/lib/bpf/libbpf.map
> @@ -436,6 +436,10 @@ LIBBPF_1.6.0 {
> bpf_linker__add_buf;
> bpf_linker__add_fd;
> bpf_linker__new_fd;
> + bpf_map__lookup_elem_opts;
> + bpf_map__update_elem_opts;
> + bpf_map_lookup_elem_opts;
> + bpf_map_update_elem_opts;
I'm planning to cut libbpf 1.6 release early next week, so for the
next revision please add it into 1.7 section
> bpf_object__prepare;
> bpf_prog_stream_read;
> bpf_program__attach_cgroup_opts;
> diff --git a/tools/lib/bpf/libbpf_common.h b/tools/lib/bpf/libbpf_common.h
> index 8fe248e14eb6..84ca89ace1be 100644
> --- a/tools/lib/bpf/libbpf_common.h
> +++ b/tools/lib/bpf/libbpf_common.h
> @@ -89,4 +89,18 @@
> memcpy(&NAME, &___##NAME, sizeof(NAME)); \
> } while (0)
>
> +struct bpf_map_update_elem_opts {
> + size_t sz; /* size of this struct for forward/backward compatibility */
> + __u64 flags;
> + __u32 cpu;
> + size_t:0;
> +};
> +
> +struct bpf_map_lookup_elem_opts {
> + size_t sz; /* size of this struct for forward/backward compatibility */
> + __u64 flags;
> + __u32 cpu;
> + size_t:0;
> +};
> +
> #endif /* __LIBBPF_LIBBPF_COMMON_H */
> --
> 2.50.0
>
