From: "Yordan Karadzhov (VMware)" <y.karadz@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: rostedt@goodmis.org, tglx@linutronix.de, peterz@infradead.org,
"Yordan Karadzhov (VMware)" <y.karadz@gmail.com>
Subject: [PATCH v4 5/6] tracing: Unify the logic for function tracing options
Date: Thu, 15 Apr 2021 21:18:53 +0300 [thread overview]
Message-ID: <20210415181854.147448-6-y.karadz@gmail.com> (raw)
In-Reply-To: <20210415181854.147448-1-y.karadz@gmail.com>
Currently the logic for dealing with the options for function tracing
has two different implementations. One is used when we set the flags
(in "static int func_set_flag()") and another used when we initialize
the tracer (in "static int function_trace_init()"). Those two
implementations are meant to do essentially the same thing and they
are both not very convenient for adding new options. In this patch
we add a helper function that provides a single implementation of
the logic for dealing with the options and we make it such that new
options can be easily added.
Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
---
kernel/trace/trace_functions.c | 65 ++++++++++++++++++++--------------
1 file changed, 38 insertions(+), 27 deletions(-)
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index f93723ca66bc..f37f73a9b1b8 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -31,9 +31,12 @@ static struct tracer_flags func_flags;
/* Our option */
enum {
+ TRACE_FUNC_NO_OPTS = 0x0, /* No flags set. */
TRACE_FUNC_OPT_STACK = 0x1,
};
+#define TRACE_FUNC_OPT_MASK (TRACE_FUNC_OPT_STACK)
+
int ftrace_allocate_ftrace_ops(struct trace_array *tr)
{
struct ftrace_ops *ops;
@@ -86,6 +89,18 @@ void ftrace_destroy_function_files(struct trace_array *tr)
ftrace_free_ftrace_ops(tr);
}
+static ftrace_func_t select_trace_function(u32 flags_val)
+{
+ switch (flags_val & TRACE_FUNC_OPT_MASK) {
+ case TRACE_FUNC_NO_OPTS:
+ return function_trace_call;
+ case TRACE_FUNC_OPT_STACK:
+ return function_stack_trace_call;
+ default:
+ return NULL;
+ }
+}
+
static int function_trace_init(struct trace_array *tr)
{
ftrace_func_t func;
@@ -97,12 +112,9 @@ static int function_trace_init(struct trace_array *tr)
if (!tr->ops)
return -ENOMEM;
- /* Currently only the global instance can do stack tracing */
- if (tr->flags & TRACE_ARRAY_FL_GLOBAL &&
- func_flags.val & TRACE_FUNC_OPT_STACK)
- func = function_stack_trace_call;
- else
- func = function_trace_call;
+ func = select_trace_function(func_flags.val);
+ if (!func)
+ return -EINVAL;
ftrace_init_array_ops(tr, func);
@@ -213,7 +225,7 @@ static struct tracer_opt func_opts[] = {
};
static struct tracer_flags func_flags = {
- .val = 0, /* By default: all flags disabled */
+ .val = TRACE_FUNC_NO_OPTS, /* By default: all flags disabled */
.opts = func_opts
};
@@ -235,30 +247,29 @@ static struct tracer function_trace;
static int
func_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
{
- switch (bit) {
- case TRACE_FUNC_OPT_STACK:
- /* do nothing if already set */
- if (!!set == !!(func_flags.val & TRACE_FUNC_OPT_STACK))
- break;
-
- /* We can change this flag when not running. */
- if (tr->current_trace != &function_trace)
- break;
+ ftrace_func_t func;
+ u32 new_flags;
- unregister_ftrace_function(tr->ops);
+ /* Do nothing if already set. */
+ if (!!set == !!(func_flags.val & bit))
+ return 0;
- if (set) {
- tr->ops->func = function_stack_trace_call;
- register_ftrace_function(tr->ops);
- } else {
- tr->ops->func = function_trace_call;
- register_ftrace_function(tr->ops);
- }
+ /* We can change this flag only when not running. */
+ if (tr->current_trace != &function_trace)
+ return 0;
- break;
- default:
+ new_flags = (func_flags.val & ~bit) | (set ? bit : 0);
+ func = select_trace_function(new_flags);
+ if (!func)
return -EINVAL;
- }
+
+ /* Check if there's anything to change. */
+ if (tr->ops->func == func)
+ return 0;
+
+ unregister_ftrace_function(tr->ops);
+ tr->ops->func = func;
+ register_ftrace_function(tr->ops);
return 0;
}
--
2.25.1
next prev parent reply other threads:[~2021-04-15 18:19 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-15 18:18 [PATCH v4 0/6] Add "func_no_repete" tracing option Yordan Karadzhov (VMware)
2021-04-15 18:18 ` [PATCH v4 1/6] tracing: Define static void trace_print_time() Yordan Karadzhov (VMware)
2021-04-15 18:18 ` [PATCH v4 2/6] tracing: Define new ftrace event "func_repeats" Yordan Karadzhov (VMware)
2021-04-15 18:18 ` [PATCH v4 3/6] tracing: Add "last_func_repeats" to struct trace_array Yordan Karadzhov (VMware)
2021-04-15 18:18 ` [PATCH v4 4/6] tracing: Add method for recording "func_repeats" events Yordan Karadzhov (VMware)
2021-04-15 18:18 ` Yordan Karadzhov (VMware) [this message]
2021-04-15 18:18 ` [PATCH v4 6/6] tracing: Add "func_no_repeats" option for function tracing Yordan Karadzhov (VMware)
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=20210415181854.147448-6-y.karadz@gmail.com \
--to=y.karadz@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).