3.16.72-rc1 review patch. If anyone has any objections, please let me know.
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From: Frederic Weisbecker frederic@kernel.org
commit f54bb2ec02c839f6bfe3e8d438cd93d30b4809dd upstream.
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.or... Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Ben Hutchings ben@decadent.org.uk --- include/linux/lockdep.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+)
--- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -525,9 +525,24 @@ do { \ lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_); \ lock_release(&(lock)->dep_map, 0, _THIS_IP_); \ } 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 # define might_lock(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
#ifdef CONFIG_PROVE_RCU