On Thu 02-01-14 11:14:06, tj@xxxxxxxxxx wrote: > Hey, again. > > On Thu, Jan 02, 2014 at 11:01:02AM -0500, tj@xxxxxxxxxx wrote: > > What we're missing is a way to make such split visible in the upper > > layers for writeback. It seems rather clear to me that that's the > > right way to approach the problem rather than implementing separate > > control for writebacks and somehow coordinate that with the rest. > > To clarify a bit. I think what we need to do is splitting bdi's for > each active blkcg (at least the part which is relevant to propagating > io pressure upwards). Well, the pressure is currently propagated by the fact that we block on request allocation while writing back stuff... So this would mean splitting bdi flusher workqueue per blkcg. > I really don't think a scheme where we try to somehow split bandwidth > number between two separate enforcing mechanisms is something we should > go after. Agreed. Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
