linux-stable/include/linux/debug_locks.h
Waiman Long 01a14bda11 locking/lockdep: Make global debug_locks* variables read-mostly
Make the frequently used lockdep global variable debug_locks read-mostly.
As debug_locks_silent is sometime used together with debug_locks,
it is also made read-mostly so that they can be close together.

With false cacheline sharing, cacheline contention problem can happen
depending on what get put into the same cacheline as debug_locks.

Signed-off-by: Waiman Long <longman@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/1539913518-15598-2-git-send-email-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-19 07:53:18 +02:00

76 lines
1.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_DEBUG_LOCKING_H
#define __LINUX_DEBUG_LOCKING_H
#include <linux/kernel.h>
#include <linux/atomic.h>
#include <linux/bug.h>
struct task_struct;
extern int debug_locks __read_mostly;
extern int debug_locks_silent __read_mostly;
static inline int __debug_locks_off(void)
{
return xchg(&debug_locks, 0);
}
/*
* Generic 'turn off all lock debugging' function:
*/
extern int debug_locks_off(void);
#define DEBUG_LOCKS_WARN_ON(c) \
({ \
int __ret = 0; \
\
if (!oops_in_progress && unlikely(c)) { \
if (debug_locks_off() && !debug_locks_silent) \
WARN(1, "DEBUG_LOCKS_WARN_ON(%s)", #c); \
__ret = 1; \
} \
__ret; \
})
#ifdef CONFIG_SMP
# define SMP_DEBUG_LOCKS_WARN_ON(c) DEBUG_LOCKS_WARN_ON(c)
#else
# define SMP_DEBUG_LOCKS_WARN_ON(c) do { } while (0)
#endif
#ifdef CONFIG_DEBUG_LOCKING_API_SELFTESTS
extern void locking_selftest(void);
#else
# define locking_selftest() do { } while (0)
#endif
struct task_struct;
#ifdef CONFIG_LOCKDEP
extern void debug_show_all_locks(void);
extern void debug_show_held_locks(struct task_struct *task);
extern void debug_check_no_locks_freed(const void *from, unsigned long len);
extern void debug_check_no_locks_held(void);
#else
static inline void debug_show_all_locks(void)
{
}
static inline void debug_show_held_locks(struct task_struct *task)
{
}
static inline void
debug_check_no_locks_freed(const void *from, unsigned long len)
{
}
static inline void
debug_check_no_locks_held(void)
{
}
#endif
#endif