On Tue, Dec 05, 2017 at 09:51:48PM +0200, Michael S. Tsirkin wrote: > On Tue, Dec 05, 2017 at 11:33:39AM -0800, Paul E. McKenney wrote: > > On Tue, Dec 05, 2017 at 09:24:21PM +0200, Michael S. Tsirkin wrote: [ . . . ] > > > and this barrier is no longer paired with anything until > > > you realize there's a dependency barrier within READ_ONCE. > > > > > > Barrier pairing was a useful tool to check code validity, > > > maybe there are other, better tools now. > > > > There are quite a few people who say that smp_store_release() is > > easier for the tools to analyze than is smp_wmb(). My experience with > > smp_read_barrier_depends() and rcu_dereference() leads me to believe > > that they are correct. > > OK, but smp_store_release is still not paired with anything since we > rely on READ_ONCE to include the implicit dpendendency barrier. Why wouldn't you consider the smp_store_release() to be paired with the new improved READ_ONCE()? Thanx, Paul _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
