| Date | Tue, 05 May 2020 15:16:32 +0200 | From | Thomas Gleixner <> | Subject | [patch V4 part 1 30/36] lockdep: Always inline lockdep_{off,on}() |
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From: Peter Zijlstra <peterz@infradead.org>
These functions are called {early,late} in nmi_{enter,exit} and should not be traced or probed. They are also puny, so 'inline' them.
Reported-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- include/linux/lockdep.h | 23 +++++++++++++++++++++-- kernel/locking/lockdep.c | 19 ------------------- 2 files changed, 21 insertions(+), 21 deletions(-)
--- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -308,8 +308,27 @@ extern void lockdep_set_selftest_task(st extern void lockdep_init_task(struct task_struct *task); -extern void lockdep_off(void); -extern void lockdep_on(void); +/* + * Split the recrursion counter in two to readily detect 'off' vs recursion. + */ +#define LOCKDEP_RECURSION_BITS 16 +#define LOCKDEP_OFF (1U << LOCKDEP_RECURSION_BITS) +#define LOCKDEP_RECURSION_MASK (LOCKDEP_OFF - 1) + +/* + * lockdep_{off,on}() are macros to avoid tracing and kprobes; not inlines due + * to header dependencies. + */ + +#define lockdep_off() \ +do { \ + current->lockdep_recursion += LOCKDEP_OFF; \ +} while (0) + +#define lockdep_on() \ +do { \ + current->lockdep_recursion -= LOCKDEP_OFF; \ +} while (0) extern void lockdep_register_key(struct lock_class_key *key); extern void lockdep_unregister_key(struct lock_class_key *key); --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -393,25 +393,6 @@ void lockdep_init_task(struct task_struc task->lockdep_recursion = 0; } -/* - * Split the recrursion counter in two to readily detect 'off' vs recursion. - */ -#define LOCKDEP_RECURSION_BITS 16 -#define LOCKDEP_OFF (1U << LOCKDEP_RECURSION_BITS) -#define LOCKDEP_RECURSION_MASK (LOCKDEP_OFF - 1) - -void lockdep_off(void) -{ - current->lockdep_recursion += LOCKDEP_OFF; -} -EXPORT_SYMBOL(lockdep_off); - -void lockdep_on(void) -{ - current->lockdep_recursion -= LOCKDEP_OFF; -} -EXPORT_SYMBOL(lockdep_on); - static inline void lockdep_recursion_finish(void) { if (WARN_ON_ONCE(--current->lockdep_recursion))
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