On Fri, Dec 19, 2025 at 8:02 AM Andrii Nakryiko
<andrii.nakryiko@gmail.com> wrote:
>
> On Thu, Dec 18, 2025 at 3:31 AM Donglin Peng <dolinux.peng@gmail.com> wrote:
> >
> > From: pengdonglin <pengdonglin@xiaomi.com>
> >
> > Currently, vmlinux BTF is unconditionally sorted during
> > the build phase. The function btf_find_by_name_kind
> > executes the binary search branch, so find_bpffs_btf_enums
> > can be optimized by using btf_find_by_name_kind.
> >
> > Cc: Eduard Zingerman <eddyz87@gmail.com>
> > Cc: Alexei Starovoitov <ast@kernel.org>
> > Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
> > Cc: Alan Maguire <alan.maguire@oracle.com>
> > Cc: Ihor Solodrai <ihor.solodrai@linux.dev>
> > Cc: Xiaoqin Zhang <zhangxiaoqin@xiaomi.com>
> > Signed-off-by: pengdonglin <pengdonglin@xiaomi.com>
> > Acked-by: Eduard Zingerman <eddyz87@gmail.com>
> > ---
> > kernel/bpf/inode.c | 42 +++++++++++++++++++-----------------------
> > 1 file changed, 19 insertions(+), 23 deletions(-)
> >
> > diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
> > index 9f866a010dad..050fde1cf211 100644
> > --- a/kernel/bpf/inode.c
> > +++ b/kernel/bpf/inode.c
> > @@ -600,10 +600,18 @@ struct bpffs_btf_enums {
> >
> > static int find_bpffs_btf_enums(struct bpffs_btf_enums *info)
> > {
> > + struct {
> > + const struct btf_type **type;
> > + const char *name;
> > + } btf_enums[] = {
> > + {&info->cmd_t, "bpf_cmd"},
> > + {&info->map_t, "bpf_map_type"},
> > + {&info->prog_t, "bpf_prog_type"},
> > + {&info->attach_t, "bpf_attach_type"},
> > + };
> > const struct btf *btf;
> > const struct btf_type *t;
> > - const char *name;
> > - int i, n;
> > + int i, id;
> >
> > memset(info, 0, sizeof(*info));
> >
> > @@ -615,30 +623,18 @@ static int find_bpffs_btf_enums(struct bpffs_btf_enums *info)
> >
> > info->btf = btf;
> >
> > - for (i = 1, n = btf_nr_types(btf); i < n; i++) {
> > - t = btf_type_by_id(btf, i);
> > - if (!btf_type_is_enum(t))
> > - continue;
> > + for (i = 0; i < ARRAY_SIZE(btf_enums); i++) {
> > + id = btf_find_by_name_kind(btf, btf_enums[i].name,
> > + BTF_KIND_ENUM);
> > + if (id < 0)
> > + goto out;
> >
> > - name = btf_name_by_offset(btf, t->name_off);
> > - if (!name)
> > - continue;
>
> return -ESRCH, why goto at all?
>
> > -
> > - if (strcmp(name, "bpf_cmd") == 0)
> > - info->cmd_t = t;
> > - else if (strcmp(name, "bpf_map_type") == 0)
> > - info->map_t = t;
> > - else if (strcmp(name, "bpf_prog_type") == 0)
> > - info->prog_t = t;
> > - else if (strcmp(name, "bpf_attach_type") == 0)
> > - info->attach_t = t;
> > - else
> > - continue;
> > -
> > - if (info->cmd_t && info->map_t && info->prog_t && info->attach_t)
> > - return 0;
> > + t = btf_type_by_id(btf, id);
> > + *btf_enums[i].type = t;
>
> nit: drop t local variable, just assign directly:
>
> *btf_enums[i].type = btf_type_by_id(btf, id);
Thanks, I will do it.
>
> > }
> >
> > + return 0;
> > +out:
> > return -ESRCH;
> > }
> >
> > --
> > 2.34.1
> >