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Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Alexei Starovoitov , Daniel Borkmann , Marcelo Ricardo Leitner , Xin Long , Jon Maloy , Aaron Conole , Eelco Chaudron , Ilya Maximets , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-sctp@vger.kernel.org, tipc-discussion@lists.sourceforge.net, dev@openvswitch.org, Oded Gabbay , Koby Elbaz , dri-devel@lists.freedesktop.org, "Rafael J. Wysocki" , Viresh Kumar , "Gautham R. Shenoy" , Huang Rui , Mario Limonciello , Len Brown , Srinivas Pandruvada , linux-pm@vger.kernel.org, MyungJoo Ham , Kyungmin Park , Chanwoo Choi , =?UTF-8?Q?Christian_K=C3=B6nig?= , Sumit Semwal , linaro-mm-sig@lists.linaro.org, Eddie James , Andrew Jeffery , Joel Stanley , linux-fsi@lists.ozlabs.org, David Airlie , Simona Vetter , Alex Deucher , Danilo Krummrich , Matthew Brost , Philipp Stanner , Harry Wentland , Leo Li , amd-gfx@lists.freedesktop.org, Jiri Kosina , Benjamin Tissoires , linux-input@vger.kernel.org, Wolfram Sang , linux-i2c@vger.kernel.org, Mark Brown , Michael Hennerich , =?UTF-8?Q?Nuno_S=C3=A1?= , linux-spi@vger.kernel.org, "James E.J. Bottomley" , "Martin K. Petersen" , linux-scsi@vger.kernel.org, Chris Mason , David Sterba , linux-btrfs@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260312150523.2054552-1-vineeth@bitbyteword.org> From: Mathieu Desnoyers Content-Language: en-US In-Reply-To: <20260312150523.2054552-1-vineeth@bitbyteword.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: YQZPR01CA0182.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:c01:8b::24) To YT2PR01MB9175.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:be::5) Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: YT2PR01MB9175:EE_|YT3PR01MB10299:EE_ X-MS-Office365-Filtering-Correlation-Id: 4297b093-1e48-489f-e898-08de8049d0c7 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|376014|7416014|1800799024|56012099003|18002099003|22082099003; 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> > trace_foo() internally re-evaluates the static_branch_unlikely() key. > Since static branches are patched binary instructions the compiler cannot > fold the two evaluations, so every such site pays the cost twice. > > This series introduces trace_invoke_##name() as a companion to > trace_##name(). It calls __do_trace_##name() directly, bypassing the > redundant static-branch re-check, while preserving all other correctness > properties of the normal path (RCU-watching assertion, might_fault() for > syscall tracepoints). The internal __do_trace_##name() symbol is not > leaked to call sites; trace_invoke_##name() is the only new public API. > > if (trace_foo_enabled() && cond) > trace_invoke_foo(args); /* calls __do_trace_foo() directly */ FYI, we have a similar concept in LTTng-UST for userspace instrumentation already: if (lttng_ust_tracepoint_enabled(provider, name)) lttng_ust_do_tracepoint(provider, name, ...); Perhaps it can provide some ideas about API naming. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. https://www.efficios.com