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From: "Daniel Xu" <dxu@dxuuu.xyz>
To: "Lorenz Bauer" <lmb@isovalent.com>,
	"Arnd Bergmann" <arnd@arndb.de>,
	"Alexei Starovoitov" <ast@kernel.org>,
	"Daniel Borkmann" <daniel@iogearbox.net>,
	"Andrii Nakryiko" <andrii@kernel.org>,
	"Martin KaFai Lau" <martin.lau@linux.dev>,
	"Eduard Zingerman" <eddyz87@gmail.com>,
	"Song Liu" <song@kernel.org>,
	"Yonghong Song" <yonghong.song@linux.dev>,
	"John Fastabend" <john.fastabend@gmail.com>,
	"KP Singh" <kpsingh@kernel.org>,
	"Stanislav Fomichev" <sdf@fomichev.me>,
	"Hao Luo" <haoluo@google.com>, "Jiri Olsa" <jolsa@kernel.org>,
	"Mykola Lysenko" <mykolal@fb.com>,
	"Shuah Khan" <shuah@kernel.org>
Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
	"bpf@vger.kernel.org" <bpf@vger.kernel.org>,
	linux-kselftest@vger.kernel.org
Subject: Re: [PATCH bpf-next 0/2] Allow mmap of /sys/kernel/btf/vmlinux
Date: Thu, 01 May 2025 08:58:46 -0700	[thread overview]
Message-ID: <ec03896b-feac-4fa5-a213-7e9f57e15f72@app.fastmail.com> (raw)
In-Reply-To: <20250501-vmlinux-mmap-v1-0-aa2724572598@isovalent.com>

On Thu, May 1, 2025, at 7:28 AM, Lorenz Bauer wrote:
> 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%.

Cool! Maybe teach libbpf to use this as well? So everyone else can pick up
the win transparently.

>
> Signed-off-by: Lorenz Bauer <lmb@isovalent.com>
> ---
> Lorenz Bauer (2):
>       btf: allow mmap of vmlinux btf
>       selftests: bpf: add a test for mmapable vmlinux BTF
>
>  include/asm-generic/vmlinux.lds.h                  |  3 +-
>  kernel/bpf/sysfs_btf.c                             | 25 ++++++-
>  tools/testing/selftests/bpf/prog_tests/btf_sysfs.c | 79 ++++++++++++++++++++++
>  3 files changed, 104 insertions(+), 3 deletions(-)
> ---
> base-commit: 38d976c32d85ef12dcd2b8a231196f7049548477
> change-id: 20250501-vmlinux-mmap-2ec5563c3ef1
>
> Best regards,
> -- 
> Lorenz Bauer <lmb@isovalent.com>

      parent reply	other threads:[~2025-05-01 15:59 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-05-01 14:28 [PATCH bpf-next 0/2] Allow mmap of /sys/kernel/btf/vmlinux Lorenz Bauer
2025-05-01 14:28 ` [PATCH bpf-next 1/2] btf: allow mmap of vmlinux btf Lorenz Bauer
2025-05-01 20:26   ` Alexei Starovoitov
2025-05-02 10:19     ` Lorenz Bauer
2025-05-01 14:28 ` [PATCH bpf-next 2/2] selftests: bpf: add a test for mmapable vmlinux BTF Lorenz Bauer
2025-05-01 15:58 ` Daniel Xu [this message]

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