LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Masami Hiramatsu <mhiramat@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Masami Hiramatsu <mhiramat@kernel.org>
Subject: [PATCH] tracing/boot: Initialize per-instance event list in early boot
Date: Fri, 25 Sep 2020 01:40:08 +0900
Message-ID: <160096560826.182763.17110991546046128881.stgit@devnote2> (raw)
In-Reply-To: <20200924085214.f2e901534037bede0bb55447@kernel.org>

Initialize per-instance event list in early boot time (before
initializing instance directory on tracefs). This fixes boot-time
tracing to correctly handle the boot-time per-instance settings.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 kernel/trace/trace.c        |    3 ++-
 kernel/trace/trace.h        |    1 +
 kernel/trace/trace_events.c |   30 ++++++++++++++++--------------
 3 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index f7696db52e7d..400ed1ec3b64 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -8700,7 +8700,8 @@ static struct trace_array *trace_array_create(const char *name)
 		ret = trace_array_create_dir(tr);
 		if (ret)
 			goto out_free_tr;
-	}
+	} else
+		__trace_early_add_events(tr);
 
 	list_add(&tr->list, &ftrace_trace_arrays);
 
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index e1b3061ce06d..5b887cfbe5ec 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1658,6 +1658,7 @@ extern void trace_event_enable_tgid_record(bool enable);
 extern int event_trace_init(void);
 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
 extern int event_trace_del_tracer(struct trace_array *tr);
+extern void __trace_early_add_events(struct trace_array *tr);
 
 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
 						  const char *system,
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 720b0d72ea52..8ce334297bf3 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -3131,14 +3131,13 @@ static inline int register_event_cmds(void) { return 0; }
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
 /*
- * The top level array has already had its trace_event_file
- * descriptors created in order to allow for early events to
- * be recorded. This function is called after the tracefs has been
- * initialized, and we now have to create the files associated
- * to the events.
+ * The top level array and trace arrays created by boot-time tracing
+ * have already had its trace_event_file descriptors created in order
+ * to allow for early events to be recorded.
+ * This function is called after the tracefs has been initialized,
+ * and we now have to create the files associated to the events.
  */
-static __init void
-__trace_early_add_event_dirs(struct trace_array *tr)
+static void __trace_early_add_event_dirs(struct trace_array *tr)
 {
 	struct trace_event_file *file;
 	int ret;
@@ -3153,13 +3152,12 @@ __trace_early_add_event_dirs(struct trace_array *tr)
 }
 
 /*
- * For early boot up, the top trace array requires to have
- * a list of events that can be enabled. This must be done before
- * the filesystem is set up in order to allow events to be traced
- * early.
+ * For early boot up, the top trace array and the trace arrays created
+ * by boot-time tracing require to have a list of events that can be
+ * enabled. This must be done before the filesystem is set up in order
+ * to allow events to be traced early.
  */
-static __init void
-__trace_early_add_events(struct trace_array *tr)
+void __trace_early_add_events(struct trace_array *tr)
 {
 	struct trace_event_call *call;
 	int ret;
@@ -3290,7 +3288,11 @@ int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
 		goto out;
 
 	down_write(&trace_event_sem);
-	__trace_add_event_dirs(tr);
+	/* If tr already has the event list, it is initialized in early boot. */
+	if (unlikely(!list_empty(&tr->events)))
+		__trace_early_add_event_dirs(tr);
+	else
+		__trace_add_event_dirs(tr);
 	up_write(&trace_event_sem);
 
  out:


  reply index

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-22  1:24 [for-next][PATCH 00/26] tracing: Updates for 5.10 Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 01/26] tools/bootconfig: Show bootconfig compact tree from bootconfig file Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 02/26] tools/bootconfig: Add list option Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 03/26] tools/bootconfig: Make all functions static Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 04/26] tools/bootconfig: Add a script to generate ftrace shell-command from bootconfig Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 05/26] tools/bootconfig: Add a script to generates bootconfig from ftrace Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 06/26] tools/bootconfig: Add --init option for bconf2ftrace.sh Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 07/26] tracing: toplevel d_entry already initialized Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 08/26] tracing: make tracing_init_dentry() returns an integer instead of a d_entry pointer Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 09/26] tracing: Delete repeated words in comments Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 10/26] tracing: Use __this_cpu_read() in trace_buffered_event_enable() Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 11/26] kprobes: Use module_name() macro Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 12/26] tracing: remove a pointless assignment Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 13/26] fgraph: Convert ret_stack tasklist scanning to rcu Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 14/26] tracing/boot: Add per-instance tracing_on option support Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 15/26] Documentation: tracing: Add tracing_on option to boot-time tracer Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 16/26] tracing/kprobes: Support perf-style return probe Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 17/26] tracing/uprobes: " Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 18/26] Documentation: tracing: Add %return suffix description Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 19/26] Documentation: tracing: boot: Add an example of tracing function-calls Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 20/26] selftests/ftrace: Add %return suffix tests Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 21/26] kprobes: Init kprobes in early_initcall Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 22/26] tracing: Define event fields early stage Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 23/26] tracing: Enable adding dynamic events " Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 24/26] tracing: Enable creating new instance early boot Steven Rostedt
2020-09-23 23:52   ` Masami Hiramatsu
2020-09-24 16:40     ` Masami Hiramatsu [this message]
2020-09-25 19:37       ` [PATCH] tracing/boot: Initialize per-instance event list in " Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 25/26] tracing/boot, kprobe, synth: Initialize boot-time tracing earlier Steven Rostedt
2020-09-22  1:24 ` [for-next][PATCH 26/26] Documentation: tracing: Add the startup timing of boot-time tracing Steven Rostedt

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=160096560826.182763.17110991546046128881.stgit@devnote2 \
    --to=mhiramat@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=rostedt@goodmis.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git
	git clone --mirror https://lore.kernel.org/lkml/8 lkml/git/8.git
	git clone --mirror https://lore.kernel.org/lkml/9 lkml/git/9.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git