On Fri, Sep 28, 2012 at 11:45:21AM -0600, Zach Brown wrote: > > When we truncate existing items in the tree log we've been searching for > > each individual item and removing them. This is unnecessary churn and > > searching, just keep track of the slot we are on and how many items we need > > to delete and delete them all at once. Thanks, > > (speaking of unnecessary churn :)) > > > +next_slot: > > path->slots[0]--; > > + > > btrfs_item_key_to_cpu(path->nodes[0], &found_key, > > path->slots[0]); > > > > if (found_key.objectid != objectid) > > break; > > > > - ret = btrfs_del_item(trans, log, path); > > + start_slot = path->slots[0]; > > + del_nr++; > > + if (start_slot) > > + goto next_slot; > > A linear backwards scan? Of potentially 64k leaves? > > Can you use bin_search() to look for the first key >= [objectid,0,0] in > the leaf? And probably a single comparison of slot 0 to fast path the > case where the whole leaf contains the object id? > Yeah I can do that. > > + ret = btrfs_del_items(trans, log, path, start_slot, del_nr); > > if (ret) > > break; > > btrfs_release_path(path); > > } > > + if (!ret && del_nr) > > + ret = btrfs_del_items(trans, log, path, start_slot, del_nr); > > btrfs_release_path(path); > > You shouldn't have to duplicate deletion and releasing the path if you > wrap the calculation of start_slot and nr in a helper. Something like: > > nr = find_nr_and_slot_doo_de_doo(, &start_slot); > if (nr > 0) > btrfs_del_items(, start_slot, nr); K, I'll fix that up, thanks. Josef -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
