On Tue, Dec 01, 2009 at 07:00:41AM -0700, Matthew Wilcox wrote: > On Tue, Dec 01, 2009 at 09:21:32PM +0800, Liuweni wrote: > > * BUGS: > > * With a large number of inodes live on the file system this function > > * currently becomes quite slow. > > > > I don't believe that comment is correct. In any case, your optimisation > wouldn't make a lick of difference to the speed; it's a single comparison > in a loop which also calculates a hash, makes a function call, and walks > the length of a hash chain. > > The old adage about debugging code, not comments applies here. Don't take > somebody else's word for it that there's a performance problem here. > Devise a test to demonstrate the performance problem. Otherwise, how > will you know if you solved it? Yeah I agree. And then we can debate the usefulness of that workload. iunique is not used in many filesystems. If performance really becomes a problem, then you most likely need another data structure. A per-sb ida or something would come to mind, but I expect any filesystem that cares already has a decent inode number allocation so iunique is just a simple hack for those that don't care so much. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
