On Fri, Dec 02, 2016 at 10:54:52PM +0100, Lucas Stach wrote: ..... > > So with the rhashtable change in place, we've already removed the > > cause of the pag_buf_lock contention (the rbtree pointer chasing) so > > there just isn't any overhead that using RCU can optimise away. > > Hence there's no gains to amortise the efficiency losses using RCU > > freeing introduces, and as a result using RCU is slower than > > traditional locking techniques. > > > > I'll keep testing the rhashtbale code - it look solid enough at this > > point to consider it for the 4.10 cycle. > > > Thanks for running those numbers. I had started to modify the patches > according to the review, but didn't get around to fix the RCU path. > > Do you still consider this change to go in with 4.10? Yes, I posted an up-to-date version of it in this series I posted last friday: https://www.spinics.net/lists/linux-xfs/msg02532.html https://www.spinics.net/lists/linux-xfs/msg02535.html Needs review before I'll merge it for 4.10, though. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
