linux-kernel - [PATCH 3/4] dyndbg: Use *no

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Message-Id: <32e18ceb528b99d9147be9c1af578a1965e2bad9.1709127473.git.geert+renesas@glider.be>
Date: Wed, 28 Feb 2024 15:00:04 +0100
From: Geert Uytterhoeven <geert+renesas@...der.be>
To: Chris Down <chris@...isdown.name>,
	Petr Mladek <pmladek@...e.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
	Jessica Yu <jeyu@...nel.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	John Ogness <john.ogness@...utronix.de>,
	Sergey Senozhatsky <senozhatsky@...omium.org>,
	Jason Baron <jbaron@...mai.com>,
	Jim Cromie <jim.cromie@...il.com>,
	Ilya Dryomov <idryomov@...il.com>,
	Xiubo Li <xiubli@...hat.com>,
	Jeff Layton <jlayton@...nel.org>
Cc: linux-kernel@...r.kernel.org,
	ceph-devel@...r.kernel.org,
	Geert Uytterhoeven <geert+renesas@...der.be>
Subject: [PATCH 3/4] dyndbg: Use *no_printk() helpers

When printk-indexing is enabled, each printk() or dev_printk()
invocation emits a pi_entry structure.  This is even true when the call
is protected by an always-false check: while the actual code to print
the message is optimized out by the compiler, the pi_entry structure is
still emitted.

Fix this by replacing "if (0) *printk(...)" constructs by calls to the
corresponding *no_printk() helpers.

Note that this has minimal impact, as most (all?) callers of
dynamic_{pr,dev}_debug() are protected by checks for DYNAMIC_DEBUG
anyway.  Still, using the helpers serves as a good example to follow.

Signed-off-by: Geert Uytterhoeven <geert+renesas@...der.be>
---
 include/linux/dynamic_debug.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 4fcbf4d4fd0a29d1..ff44ec346162a164 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -305,9 +305,9 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
 #define DYNAMIC_DEBUG_BRANCH(descriptor) false
 
 #define dynamic_pr_debug(fmt, ...)					\
-	do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
+	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 #define dynamic_dev_dbg(dev, fmt, ...)					\
-	do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
+	dev_no_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__)
 #define dynamic_hex_dump(prefix_str, prefix_type, rowsize,		\
 			 groupsize, buf, len, ascii)			\
 	do { if (0)							\
-- 
2.34.1