From: Masami Hiramatsu <mhiramat@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>,
Jonathan Corbet <corbet@lwn.net>,
Shuah Khan <skhan@linuxfoundation.org>
Cc: mhiramat@kernel.org, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org, Randy Dunlap <rdunlap@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
linux-kselftest@vger.kernel.org
Subject: [PATCH v3 7/8] Documentation: tracing: boot: Add an example of tracing function-calls
Date: Thu, 10 Sep 2020 17:56:06 +0900 [thread overview]
Message-ID: <159972816669.428528.12390560334549382316.stgit@devnote2> (raw)
In-Reply-To: <159972809455.428528.4737752126800169128.stgit@devnote2>
Add an example of tracing function calls on a specific function.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
Documentation/trace/boottime-trace.rst | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/Documentation/trace/boottime-trace.rst b/Documentation/trace/boottime-trace.rst
index 1341b449acaa..c216f5695ae2 100644
--- a/Documentation/trace/boottime-trace.rst
+++ b/Documentation/trace/boottime-trace.rst
@@ -168,6 +168,26 @@ is for tracing functions starting with "user\_", and others tracing
The instance node also accepts event nodes so that each instance
can customize its event tracing.
+With the trigger action and kprobes, you can trace function-graph while
+a function is called. For example, this will trace all function calls in
+the pci_proc_init()::
+
+ ftrace {
+ tracing_on = 0
+ tracer = function_graph
+ event.kprobes {
+ start_event {
+ probes = "pci_proc_init"
+ actions = "traceon"
+ }
+ end_event {
+ probes = "pci_proc_init%return"
+ actions = "traceoff"
+ }
+ }
+ }
+
+
This boot-time tracing also supports ftrace kernel parameters via boot
config.
For example, following kernel parameters::
next prev parent reply other threads:[~2020-09-10 8:58 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-10 8:54 [PATCH v3 0/8] tracing/boot: Add new options for tracing specific period Masami Hiramatsu
2020-09-10 8:55 ` [PATCH v3 1/8] kprobes: tracing/kprobes: Fix to kill kprobes on initmem after boot Masami Hiramatsu
2020-09-10 8:55 ` [PATCH v3 2/8] tracing/boot: Add per-instance tracing_on option support Masami Hiramatsu
2020-09-10 8:55 ` [PATCH v3 3/8] Documentation: tracing: Add tracing_on option to boot-time tracer Masami Hiramatsu
2020-09-10 13:26 ` Bird, Tim
2020-09-10 22:41 ` Masami Hiramatsu
2020-09-11 0:47 ` [PATCH v3.1 " Masami Hiramatsu
2020-09-10 8:55 ` [PATCH v3 4/8] tracing/kprobes: Support perf-style return probe Masami Hiramatsu
2020-09-10 8:55 ` [PATCH v3 5/8] tracing/uprobes: " Masami Hiramatsu
2020-09-10 8:55 ` [PATCH v3 6/8] Documentation: tracing: Add %return suffix description Masami Hiramatsu
2020-09-10 8:56 ` Masami Hiramatsu [this message]
2020-09-10 8:56 ` [PATCH v3 8/8] selftests/ftrace: Add %return suffix tests Masami Hiramatsu
2020-09-10 23:34 ` [PATCH v3 0/8] tracing/boot: Add new options for tracing specific period Steven Rostedt
2020-09-11 1:27 ` Masami Hiramatsu
2020-09-11 1:34 ` Shuah Khan
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