On Sun, 2008-11-23 at 13:39 +0000, David Woodhouse wrote: > > We don't attempt to put non-contiguous ranges into a single TRIM yet. > > We don't even merge contiguous ranges -- I still need to fix the > elevators to stop writes crossing writes, I don't think we want to do that ... it's legal if the write isn't a barrier and it will inhibit merging. That may be just fine for a SSD, but it's not for spinning media since they get better performance out of merged writes. > before we can stop discards > from also being barriers. (Discards are just writes, for the purpose of > that conversation). Perhaps they shouldn't be ... they have different characteristics. For instance, a discard may cross a read or write that has no sectors in common with it; a discard may be merged as a non contiguous range (assuming the drive supports multiple ranges), etc. I think it might be better to give it its own type for the elevators. James -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
