On Fri, Sep 09, 2016 at 10:33:06AM +0200, Christoph Hellwig wrote: > On Thu, Sep 08, 2016 at 07:45:36AM +1000, Dave Chinner wrote: > > It's a semaphore, not a mutex. Semaphore locking is independent of > > task context, the lock follows the object it protects, not the task > > that took the lock. i.e. Lockdep is wrong to assume the "owner" of a > > rw_sem will not change between lock and unlock. > > That's not the case - rw_semaphores had strict owner semanics for a > long time (although I wish we could get rid of that for a different > reason..). Do tell; note however that due to the strict write owner, we can do things like the optimistic spinning which improved writer->writer performance significantly. Also note that !owner locks create problems for RT. _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
