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[94.113.247.31]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-43d1e2a720dsm18895321f8f.4.2026.04.03.14.08.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 03 Apr 2026 14:08:38 -0700 (PDT) From: Jiri Olsa X-Google-Original-From: Jiri Olsa Date: Fri, 3 Apr 2026 23:08:35 +0200 To: Alan Maguire Cc: andrii@kernel.org, ast@kernel.org, daniel@iogearbox.net, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, qmo@kernel.org, ihor.solodrai@linux.dev, mykyta.yatsenko5@gmail.com, dwarves@vger.kernel.org, bpf@vger.kernel.org Subject: Re: [PATCH v3 dwarves 0/2] pahole: add BTF layout encoding feature Message-ID: References: <20260226085240.1908874-1-alan.maguire@oracle.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260226085240.1908874-1-alan.maguire@oracle.com> On Thu, Feb 26, 2026 at 08:52:38AM +0000, Alan Maguire wrote: > A soon-to-arrive v9 series will add support to add BTF layout > information to BTF; this describes the BTF kinds known about at > time of encoding in order to support parsing even in cases where > the kinds are not known to the parser; the layout relates a > BTF kind to the amount of space it consumes via an optional single > element following the BTF type or a set of vlen-specified objects. > > This series implements the support for the BTF "layout" feature > but does not require the libbpf changes to support it; the feature > test uses a weak declaration of btf__new_empty_opts() to handle the > unsupported case. > > To test pahole with this feature, the following approach can be used; > > 1. Specify -DLIBBPF_EMBEDDED=OFF option to cmake > 2. Install latest libbpf with associated patch series with layout support > > Alternatively with embedded libbpf the changes can be applied to > the embedded libbpf in lib/bpf/src. > > Changes since v2 [1]: > > - Resynced, renamed kind_layout -> layout > - Avoid encoding layout info in split BTF since it is a waste of space > > Changes since v1 [2]: > > - Resynced with latest pahole > > [1] https://lore.kernel.org/dwarves/20251210202752.813919-1-alan.maguire@oracle.com/ > [2] https://lore.kernel.org/dwarves/20250528095349.788793-1-alan.maguire@oracle.com/ > > Alan Maguire (2): > pahole: Add "layout" BTF encoding feature > man-pages: describe layout BTF feature lgtm Acked-by: Jiri Olsa jirka > > btf_encoder.c | 21 ++++++++++++++++++++- > dwarves.h | 4 ++++ > man-pages/pahole.1 | 2 ++ > pahole.c | 6 ++++++ > 4 files changed, 32 insertions(+), 1 deletion(-) > > -- > 2.39.3 >