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[73.202.46.50]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-227811b2b07sm111370645ad.123.2025.03.26.09.04.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 26 Mar 2025 09:04:29 -0700 (PDT) From: Howard Chu To: acme@kernel.org Cc: mingo@redhat.com, namhyung@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, irogers@google.com, adrian.hunter@intel.com, peterz@infradead.org, kan.liang@linux.intel.com, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, Howard Chu Subject: [PATCH v1] perf doc: Improve perf trace's doc on --force-btf option Date: Wed, 26 Mar 2025 09:04:16 -0700 Message-ID: <20250326160416.1725322-1-howardchu95@gmail.com> X-Mailer: git-send-email 2.45.2 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" As mentioned by Arnaldo in a past discussion (Link: https://lore.kernel.org/linux-perf-users/Z2m0pWiQgZNXhvxK@x1/), the current documentation on --force-btf is vague and inaccurate, this patch aims to provide a clearer explanation of the option. Signed-off-by: Howard Chu Suggested-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-trace.txt | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/tools/perf/Documentation/perf-trace.txt b/tools/perf/Documenta= tion/perf-trace.txt index 887dc37773d0..cf2445d2ba3d 100644 --- a/tools/perf/Documentation/perf-trace.txt +++ b/tools/perf/Documentation/perf-trace.txt @@ -246,10 +246,10 @@ the thread executes on the designated CPUs. Default i= s to monitor all CPUs. arguments to strings (pid to comm, syscall id to syscall name, etc). =20 --force-btf:: - Use btf_dump to pretty print syscall argument data, instead of using hand= -crafted pretty - printers. This option is intended for testing BTF integration in perf tra= ce. btf_dump-based - pretty-printing serves as a fallback to hand-crafted pretty printers, as = the latter can - better pretty-print integer flags and struct pointers. + Use libbpf's btf_dump to pretty print syscall arguments, utilizing only t= he debug + information from BTF. This option is intended for testing BTF integration= in perf + trace. Using libbpf is a fallback to perf trace's own prettifiers generat= ed from the + kernel source, as the latter can better pretty-print integer flags and st= ruct members. =20 PAGEFAULTS ---------- --=20 2.45.2