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From: Howard Chu <howardchu95@gmail.com>
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 <howardchu95@gmail.com>
Subject: [PATCH v1] perf doc: Improve perf trace's doc on --force-btf option
Date: Wed, 26 Mar 2025 09:04:16 -0700	[thread overview]
Message-ID: <20250326160416.1725322-1-howardchu95@gmail.com> (raw)

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 <howardchu95@gmail.com>
Suggested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
---
 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/Documentation/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 is to monitor all CPUs.
 	arguments to strings (pid to comm, syscall id to syscall name, etc).
 
 --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 trace. 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 the 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 generated from the
+	kernel source, as the latter can better pretty-print integer flags and struct members.
 
 PAGEFAULTS
 ----------
-- 
2.45.2


             reply	other threads:[~2025-03-26 16:04 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-03-26 16:04 Howard Chu [this message]
2025-03-26 18:14 ` Namhyung Kim
2025-03-26 18:22   ` Howard Chu

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