On Tue, May 29, 2012 at 11:15:58AM +0900, Tejun Heo wrote: > Hello, > > On Tue, May 29, 2012 at 12:08:15PM +1000, Dave Chinner wrote: > > > i thought a bit more about it and the only thing which makes sense to > > > me is exposing the stripe granularity for striped devices - > > > ie. something which says "if you go across this boundary, the > > > performance characteristics including latency might get affected", > > > which should fit nicely with the rest of topology information. > > > Martin, adding that shouldn't be difficult, right? > > > > We already have the optimal IO size/alignment field in the topology. > > Doesn't this fit what you want exactly? > > I don't know how xfs/ext4 is currently benefiting from > merge_bvec_fn(), so I'm unsure. If the existing ones are enough, > great. Excepting readahead I don't think they are at all. For readahead all we need is a hint - call it "atomic IO size" or something. Assuming one of the gazillion things in queue_limits doesn't already mean that anyways. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
