On Tue, Aug 17, 2010 at 11:33:52AM +0200, Tejun Heo wrote: > > That logic wasn't just about retries (at least not in the latest > > kernel). With commit 708e929513502fb0 the -EOPNOTSUPP checking also > > serves to optimize the barrier+discard case (when discards aren't > > supported). > > With the patch applied, there's no second flush. Those requests would > now be REQ_FLUSH + REQ_DISCARD. The first can't be avoided anyway and > there won't be the second flush to begin with, so I don't think this > worsens anything. In fact the pre-flush is completely superflous for discards, but that's a separate discussion and should not be changed as part of this patchset but rather explicitly. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
