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authorPeter Zijlstra <peterz@infradead.org>2020-02-04 09:34:37 +0100
committerIngo Molnar <mingo@kernel.org>2020-02-11 13:10:57 +0100
commitbcba67cd806800fa8e973ac49dbc7d2d8fb3e55e (patch)
tree3d6fe168cd5bccb14aaca011a89164534b1123ef /include/linux/rwsem.h
parent7f26482a872c36b2ee87ea95b9dcd96e3d5805df (diff)
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 <hch@infradead.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Will Deacon <will@kernel.org> Acked-by: Waiman Long <longman@redhat.com> Tested-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lkml.kernel.org/r/20200204092228.GP14946@hirez.programming.kicks-ass.net
Diffstat (limited to 'include/linux/rwsem.h')
-rw-r--r--include/linux/rwsem.h6
1 files changed, 0 insertions, 6 deletions
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)
{