Commit 7ccaba53 authored by Jan Beulich's avatar Jan Beulich Committed by Linus Torvalds
Browse files

consolidate WARN_...ONCE() static variables 



Due to the alignment of following variables, these typically consume
more than just the single byte that 'bool' requires, and as there are a
few hundred instances, the cache pollution (not so much the waste of
memory) sums up.  Put these variables into their own section, outside of
any half way frequently used memory range.

Do the same also to the __warned variable of rcu_lockdep_assert().
(Don't, however, include the ones used by printk_once() and alike, as
they can potentially be hot.)

Signed-off-by: default avatarJan Beulich <jbeulich@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 10db4e1e

include/asm-generic/bug.h

+3 −3
Original line number Diff line number Diff line
@@ -134,7 +134,7 @@ extern void warn_slowpath_null(const char *file, const int line); 
#endif



#define WARN_ON_ONCE(condition)	({				\

	static bool __warned;					\

	static bool __section(.data.unlikely) __warned;		\

	int __ret_warn_once = !!(condition);			\

								\

	if (unlikely(__ret_warn_once))				\
@@ -144,7 +144,7 @@ extern void warn_slowpath_null(const char *file, const int line); 
})



#define WARN_ONCE(condition, format...)	({			\

	static bool __warned;					\

	static bool __section(.data.unlikely) __warned;		\

	int __ret_warn_once = !!(condition);			\

								\

	if (unlikely(__ret_warn_once))				\
@@ -154,7 +154,7 @@ extern void warn_slowpath_null(const char *file, const int line); 
})



#define WARN_TAINT_ONCE(condition, taint, format...)	({	\

	static bool __warned;					\

	static bool __section(.data.unlikely) __warned;		\

	int __ret_warn_once = !!(condition);			\

								\

	if (unlikely(__ret_warn_once))				\

include/asm-generic/vmlinux.lds.h

+1 −0
Original line number Diff line number Diff line
@@ -167,6 +167,7 @@ 
	CPU_KEEP(exit.data)						\

	MEM_KEEP(init.data)						\

	MEM_KEEP(exit.data)						\

	*(.data.unlikely)						\

	STRUCT_ALIGN();							\

	*(__tracepoints)						\

	/* implement dynamic printk debug */				\

include/linux/rcupdate.h

+1 −1
Original line number Diff line number Diff line
@@ -418,7 +418,7 @@ extern int rcu_my_thread_group_empty(void); 
 */

#define rcu_lockdep_assert(c, s)					\

	do {								\

		static bool __warned;					\

		static bool __section(.data.unlikely) __warned;		\

		if (debug_lockdep_rcu_enabled() && !__warned && !(c)) {	\

			__warned = true;				\

			lockdep_rcu_suspicious(__FILE__, __LINE__, s);	\

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