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Tue, 16 Dec 2025 18:57:13 -0800 (PST) Message-ID: Subject: Re: [PATCH bpf-next v9 04/10] libbpf: Optimize type lookup with binary search for sorted BTF From: Eduard Zingerman To: Donglin Peng Cc: ast@kernel.org, andrii.nakryiko@gmail.com, zhangxiaoqin@xiaomi.com, ihor.solodrai@linux.dev, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, pengdonglin , Alan Maguire Date: Tue, 16 Dec 2025 18:57:10 -0800 In-Reply-To: References: <20251208062353.1702672-1-dolinux.peng@gmail.com> <20251208062353.1702672-5-dolinux.peng@gmail.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.56.2 (3.56.2-2.fc42) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Wed, 2025-12-17 at 10:32 +0800, Donglin Peng wrote: [...] > > > + if (unlikely(kind =3D=3D -1)) > > > + return idx; > > > + > > > + t =3D btf_type_by_id(btf, idx); > > > + if (likely(BTF_INFO_KIND(t->info) =3D=3D kind)) > > > + return idx; > > > + > > > + for (idx++; idx <=3D end_id; idx++) { > > > + t =3D btf__type_by_id(btf, idx); > > > + tname =3D btf__str_by_offset(btf, t->name_off); > > > + if (strcmp(tname, type_name) !=3D 0) > > > + return libbpf_err(-ENOENT); > > > + if (btf_kind(t) =3D=3D kind) > > ^^^^^^^^^^^^^^^^^^^ > > Is kind !=3D -1 check missing here? >=20 > The check for kind !=3D -1 is unnecessary here because it has already bee= n > performed earlier in the logic, after btf_find_by_name_bsearch successful= ly > returned a valid idx. In v8, the implementation of btf_find_by_name_bsear= ch > was refined for better performance, and when idx > 0, it guarantees that = the > name has been matched. >=20 > Thank you for the review. > Donglin Ack, missed that, thank you for explaining.