Commit f54bb2ec authored Nov 06, 2017 by Frederic Weisbecker Committed by Ingo Molnar Nov 08, 2017

locking/lockdep: Add IRQs disabled/enabled assertion APIs: lockdep_assert_irqs_enabled()/disabled()



Checking whether IRQs are enabled or disabled is a very common sanity
check, however not free of overhead especially on fastpath where such
assertion is very common.

Lockdep is a good host for such concurrency correctness check and it
even already tracks down IRQs disablement state. Just reuse its
machinery. This will allow us to get rid of the flags pop and check
overhead from fast path when kernel is built for production.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: David S . Miller <davem@davemloft.net>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/1509980490-4285-2-git-send-email-frederic@kernel.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 11752adb

include/linux/lockdep.h

+15 −0

Original line number	Original line	Diff line number	Diff line
	@@ -725,9 +725,24 @@ do { \
	lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_); \		lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_); \
	lock_release(&(lock)->dep_map, 0, _THIS_IP_); \		lock_release(&(lock)->dep_map, 0, _THIS_IP_); \
	} while (0)		} while (0)

			#define lockdep_assert_irqs_enabled() do { \
			WARN_ONCE(debug_locks && !current->lockdep_recursion && \
			!current->hardirqs_enabled, \
			"IRQs not enabled as expected\n"); \
			} while (0)

			#define lockdep_assert_irqs_disabled() do { \
			WARN_ONCE(debug_locks && !current->lockdep_recursion && \
			current->hardirqs_enabled, \
			"IRQs not disabled as expected\n"); \
			} while (0)

	#else		#else
	# define might_lock(lock) do { } while (0)		# define might_lock(lock) do { } while (0)
	# define might_lock_read(lock) do { } while (0)		# define might_lock_read(lock) do { } while (0)
			# define lockdep_assert_irqs_enabled() do { } while (0)
			# define lockdep_assert_irqs_disabled() do { } while (0)
	#endif		#endif

	#ifdef CONFIG_LOCKDEP		#ifdef CONFIG_LOCKDEP

Admin message