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[2001:8b0:7a5a:26ff::600]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3a099ae8117sm11328877f8f.56.2025.05.05.11.39.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 May 2025 11:39:39 -0700 (PDT) From: Lorenz Bauer Subject: [PATCH bpf-next v3 0/3] Allow mmap of /sys/kernel/btf/vmlinux Date: Mon, 05 May 2025 19:38:42 +0100 Message-Id: <20250505-vmlinux-mmap-v3-0-5d53afa060e8@isovalent.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-B4-Tracking: v=1; b=H4sIALIFGWgC/23NQQ7CIBQE0Ks0rMXAp1jrynsYF4i/9ictNFBJT dO7S1iZxuVkMm9WFjEQRnapVhYwUSTvclCHitneuBdyeubMQIAWWkiexoHce+HjaCYOaLU+Kau wkyxPpoAdLYW7scfUcYfLzO656SnOPnzKT5Kl/08myQU3BhqodQO6PV8p+mQGdPPR+rFgCX4B2 AGQgVZbaGStai3bPbBt2xcErgqQ9wAAAA== X-Change-ID: 20250501-vmlinux-mmap-2ec5563c3ef1 To: Arnd Bergmann , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Mykola Lysenko , Shuah Khan Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, Lorenz Bauer X-Mailer: b4 0.14.2 I'd like to cut down the memory usage of parsing vmlinux BTF in ebpf-go. With some upcoming changes the library is sitting at 5MiB for a parse. Most of that memory is simply copying the BTF blob into user space. By allowing vmlinux BTF to be mmapped read-only into user space I can cut memory usage by about 75%. Signed-off-by: Lorenz Bauer --- Changes in v3: - Remove slightly confusing calculation of trailing (Alexei) - Use vm_insert_page (Alexei) - Simplified libbpf code - Link to v2: https://lore.kernel.org/r/20250502-vmlinux-mmap-v2-0-95c271434519@isovalent.com Changes in v2: - Use btf__new in selftest - Avoid vm_iomap_memory in btf_vmlinux_mmap - Add VM_DONTDUMP - Add support to libbpf - Link to v1: https://lore.kernel.org/r/20250501-vmlinux-mmap-v1-0-aa2724572598@isovalent.com --- Lorenz Bauer (3): btf: allow mmap of vmlinux btf selftests: bpf: add a test for mmapable vmlinux BTF libbpf: Use mmap to parse vmlinux BTF from sysfs include/asm-generic/vmlinux.lds.h | 3 +- kernel/bpf/sysfs_btf.c | 37 ++++++++++ tools/lib/bpf/btf.c | 83 +++++++++++++++++++--- tools/testing/selftests/bpf/prog_tests/btf_sysfs.c | 83 ++++++++++++++++++++++ 4 files changed, 194 insertions(+), 12 deletions(-) --- base-commit: 38d976c32d85ef12dcd2b8a231196f7049548477 change-id: 20250501-vmlinux-mmap-2ec5563c3ef1 Best regards,