From bcba67cd806800fa8e973ac49dbc7d2d8fb3e55e Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 4 Feb 2020 09:34:37 +0100 Subject: locking/rwsem: Remove RWSEM_OWNER_UNKNOWN Remove the now unused RWSEM_OWNER_UNKNOWN hack. This hack breaks PREEMPT_RT and getting rid of it was the entire motivation for re-writing the percpu rwsem. The biggest problem is that it is fundamentally incompatible with any form of Priority Inheritance, any exclusively held lock must have a distinct owner. Requested-by: Christoph Hellwig Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Reviewed-by: Davidlohr Bueso Acked-by: Will Deacon Acked-by: Waiman Long Tested-by: Juri Lelli Link: https://lkml.kernel.org/r/20200204092228.GP14946@hirez.programming.kicks-ass.net --- include/linux/rwsem.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'include/linux/rwsem.h') diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 00d6054687dd..8a418d9eeb7a 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -53,12 +53,6 @@ struct rw_semaphore { #endif }; -/* - * Setting all bits of the owner field except bit 0 will indicate - * that the rwsem is writer-owned with an unknown owner. - */ -#define RWSEM_OWNER_UNKNOWN (-2L) - /* In all implementations count != 0 means locked */ static inline int rwsem_is_locked(struct rw_semaphore *sem) { -- cgit v1.2.3-59-g8ed1b