On Wed, Jun 03, 2015 at 09:19:12AM -0500, Mark Tinguely wrote: > On 05/28/15 21:16, Dave Chinner wrote: > >Discussion: > > > >I think that we will eventually need to track multiple regions - 3 > >is probably sufficient - because the nature of directory operations > >are that just about every operation modifies a header in the buffer, > >a tail section in the buffer and then some number of bytes/regions > >in the middle of the buffer. > > Nod to the idea. > > What made you change from your original idea of using 4 regions to 3 > regions? 3 or 4 regions make little difference. header, body and tail is most common for random directory modifications, so whether we have 1 or 2 body regions won't make much difference once more than a couple of modifications are made to the same directory block. Indeed, I'm not sure that we even need multiple regions - the log bandwidth and log item memcpy overhead hasn't changed very much even on large directory buffers with a single region... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
