* [PATCH] ring-buffer: make the const read-only 'type' static
@ 2025-07-14 16:08 Colin Ian King
2025-07-14 16:15 ` Steven Rostedt
2025-07-18 21:24 ` David Laight
0 siblings, 2 replies; 4+ messages in thread
From: Colin Ian King @ 2025-07-14 16:08 UTC (permalink / raw)
To: Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers,
linux-trace-kernel
Cc: kernel-janitors, linux-kernel
Don't populate the read-only 'type' on the stack at run time,
instead make it static.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
---
kernel/trace/ring_buffer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 00fc38d70e86..39aa1f50274f 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -4118,7 +4118,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_unlock_commit);
static const char *show_irq_str(int bits)
{
- const char *type[] = {
+ static const char * type[] = {
".", // 0
"s", // 1
"h", // 2
--
2.50.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] ring-buffer: make the const read-only 'type' static
2025-07-14 16:08 [PATCH] ring-buffer: make the const read-only 'type' static Colin Ian King
@ 2025-07-14 16:15 ` Steven Rostedt
2025-07-19 6:32 ` Christophe JAILLET
2025-07-18 21:24 ` David Laight
1 sibling, 1 reply; 4+ messages in thread
From: Steven Rostedt @ 2025-07-14 16:15 UTC (permalink / raw)
To: Colin Ian King
Cc: Masami Hiramatsu, Mathieu Desnoyers, linux-trace-kernel,
kernel-janitors, linux-kernel
On Mon, 14 Jul 2025 17:08:58 +0100
Colin Ian King <colin.i.king@gmail.com> wrote:
> Don't populate the read-only 'type' on the stack at run time,
> instead make it static.
Hmm, why not?
-- Steve
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] ring-buffer: make the const read-only 'type' static
2025-07-14 16:15 ` Steven Rostedt
@ 2025-07-19 6:32 ` Christophe JAILLET
0 siblings, 0 replies; 4+ messages in thread
From: Christophe JAILLET @ 2025-07-19 6:32 UTC (permalink / raw)
To: Steven Rostedt
Cc: Masami Hiramatsu, Mathieu Desnoyers, linux-trace-kernel,
kernel-janitors, linux-kernel, Colin Ian King
Le 14/07/2025 à 18:15, Steven Rostedt a écrit :
> On Mon, 14 Jul 2025 17:08:58 +0100
> Colin Ian King <colin.i.king@gmail.com> wrote:
>
>> Don't populate the read-only 'type' on the stack at run time,
>> instead make it static.
>
> Hmm, why not?
>
> -- Steve
>
>
This is more efficient because there is no need to copy things on the
stack at run-time.
It also makes binary slightly smaller.
On my x86_64, with allmodconfig:
Before:
======
229194 924492 35104 1188790 1223b6 kernel/trace/ring_buffer.o
After:
=====
228873 924268 35040 1188181 122155 kernel/trace/ring_buffer.o
CJ
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] ring-buffer: make the const read-only 'type' static
2025-07-14 16:08 [PATCH] ring-buffer: make the const read-only 'type' static Colin Ian King
2025-07-14 16:15 ` Steven Rostedt
@ 2025-07-18 21:24 ` David Laight
1 sibling, 0 replies; 4+ messages in thread
From: David Laight @ 2025-07-18 21:24 UTC (permalink / raw)
To: Colin Ian King
Cc: Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers,
linux-trace-kernel, kernel-janitors, linux-kernel
On Mon, 14 Jul 2025 17:08:58 +0100
Colin Ian King <colin.i.king@gmail.com> wrote:
> Don't populate the read-only 'type' on the stack at run time,
> instead make it static.
>
> Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
> ---
> kernel/trace/ring_buffer.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
> index 00fc38d70e86..39aa1f50274f 100644
> --- a/kernel/trace/ring_buffer.c
> +++ b/kernel/trace/ring_buffer.c
> @@ -4118,7 +4118,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_unlock_commit);
>
> static const char *show_irq_str(int bits)
> {
> - const char *type[] = {
> + static const char * type[] = {
Better would be:
static const char type[][4] = {
David
> ".", // 0
> "s", // 1
> "h", // 2
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2025-07-19 6:41 UTC | newest]
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2025-07-14 16:08 [PATCH] ring-buffer: make the const read-only 'type' static Colin Ian King
2025-07-14 16:15 ` Steven Rostedt
2025-07-19 6:32 ` Christophe JAILLET
2025-07-18 21:24 ` David Laight
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