From: Masami Hiramatsu <mhiramat@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>, Jonathan Corbet <corbet@lwn.net>
Cc: mhiramat@kernel.org, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org, Randy Dunlap <rdunlap@infradead.org>,
Ingo Molnar <mingo@kernel.org>
Subject: [PATCH 3/6] tracing: Enable adding dynamic events early stage
Date: Thu, 10 Sep 2020 21:38:58 +0900 [thread overview]
Message-ID: <159974153790.478751.3475515065034825374.stgit@devnote2> (raw)
In-Reply-To: <159974150897.478751.17933810682730471522.stgit@devnote2>
Split the event fields initialization from creating new
event directory.
This allows the boot-time tracing to define dynamic events
before initializing events directory on tracefs.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
kernel/trace/trace_events.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index a2531301b44f..720b0d72ea52 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -38,6 +38,7 @@ DEFINE_MUTEX(event_mutex);
LIST_HEAD(ftrace_events);
static LIST_HEAD(ftrace_generic_fields);
static LIST_HEAD(ftrace_common_fields);
+static bool eventdir_initialized;
#define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
@@ -2486,7 +2487,10 @@ __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
if (!file)
return -ENOMEM;
- return event_create_dir(tr->event_dir, file);
+ if (eventdir_initialized)
+ return event_create_dir(tr->event_dir, file);
+ else
+ return event_define_fields(call);
}
/*
@@ -3483,6 +3487,9 @@ __init int event_trace_init(void)
if (ret)
pr_warn("Failed to register trace events module notifier\n");
#endif
+
+ eventdir_initialized = true;
+
return 0;
}
next prev parent reply other threads:[~2020-09-10 12:46 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-10 12:38 [PATCH 0/6] tracing/boot: Start boot-time tracing in earlier stage Masami Hiramatsu
2020-09-10 12:38 ` [PATCH 1/6] kprobes: Init kprobes in early_initcall Masami Hiramatsu
2020-09-10 12:38 ` [PATCH 2/6] tracing: Define event fields early stage Masami Hiramatsu
2020-09-10 12:38 ` Masami Hiramatsu [this message]
2020-09-10 12:39 ` [PATCH 4/6] tracing: Enable creating new instance early boot Masami Hiramatsu
2020-09-10 12:39 ` [PATCH 5/6] tracing/boot,kprobe,synth: Initialize boot-time tracing earlier Masami Hiramatsu
2020-09-10 12:39 ` [PATCH 6/6] Documentation: tracing: Add the startup timing of boot-time tracing Masami Hiramatsu
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