Commit 640d1eaf authored by Jim Cromie's avatar Jim Cromie Committed by Greg Kroah-Hartman
Browse files

dyndbg: avoid calling dyndbg_emit_prefix when it has no work 



Wrap function in a static-inline one, which checks flags to avoid
calling the function unnecessarily.

And hoist its output-buffer initialization to the grand-caller, which
is already allocating the buffer on the stack, and can trivially
initialize it too.

Signed-off-by: default avatarJim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20210504222235.1033685-2-jim.cromie@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ced081a4

include/linux/dynamic_debug.h

+5 −0
Original line number Diff line number Diff line
@@ -32,6 +32,11 @@ struct _ddebug { 
#define _DPRINTK_FLAGS_INCL_FUNCNAME	(1<<2)

#define _DPRINTK_FLAGS_INCL_LINENO	(1<<3)

#define _DPRINTK_FLAGS_INCL_TID		(1<<4)



#define _DPRINTK_FLAGS_INCL_ANY		\

	(_DPRINTK_FLAGS_INCL_MODNAME | _DPRINTK_FLAGS_INCL_FUNCNAME |\

	 _DPRINTK_FLAGS_INCL_LINENO  | _DPRINTK_FLAGS_INCL_TID)



#if defined DEBUG

#define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT

#else

lib/dynamic_debug.c

+12 −7
Original line number Diff line number Diff line
@@ -586,13 +586,11 @@ static int remaining(int wrote) 
	return 0;

}



static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf)

static char *__dynamic_emit_prefix(const struct _ddebug *desc, char *buf)

{

	int pos_after_tid;

	int pos = 0;



	*buf = '\0';



	if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {

		if (in_interrupt())

			pos += snprintf(buf + pos, remaining(pos), "<intr> ");
@@ -618,11 +616,18 @@ static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf) 
	return buf;

}



static inline char *dynamic_emit_prefix(struct _ddebug *desc, char *buf)

{

	if (unlikely(desc->flags & _DPRINTK_FLAGS_INCL_ANY))

		return __dynamic_emit_prefix(desc, buf);

	return buf;

}



void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)

{

	va_list args;

	struct va_format vaf;

	char buf[PREFIX_SIZE];

	char buf[PREFIX_SIZE] = "";



	BUG_ON(!descriptor);

	BUG_ON(!fmt);
@@ -655,7 +660,7 @@ void __dynamic_dev_dbg(struct _ddebug *descriptor, 
	if (!dev) {

		printk(KERN_DEBUG "(NULL device *): %pV", &vaf);

	} else {

		char buf[PREFIX_SIZE];

		char buf[PREFIX_SIZE] = "";



		dev_printk_emit(LOGLEVEL_DEBUG, dev, "%s%s %s: %pV",

				dynamic_emit_prefix(descriptor, buf),
@@ -684,7 +689,7 @@ void __dynamic_netdev_dbg(struct _ddebug *descriptor, 
	vaf.va = &args;



	if (dev && dev->dev.parent) {

		char buf[PREFIX_SIZE];

		char buf[PREFIX_SIZE] = "";



		dev_printk_emit(LOGLEVEL_DEBUG, dev->dev.parent,

				"%s%s %s %s%s: %pV",
@@ -720,7 +725,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor, 
	vaf.va = &args;



	if (ibdev && ibdev->dev.parent) {

		char buf[PREFIX_SIZE];

		char buf[PREFIX_SIZE] = "";



		dev_printk_emit(LOGLEVEL_DEBUG, ibdev->dev.parent,

				"%s%s %s %s: %pV",