On Fri, Jul 18, 2014 at 10:25:23AM +0200, Martin Steigerwald wrote: > Am Freitag, 18. Juli 2014, 07:52:48 schrieb Dave Chinner: > > On Thu, Jul 17, 2014 at 11:34:49PM +0200, Martin Steigerwald wrote: > > > Am Donnerstag, 17. Juli 2014, 19:35:53 schrieb Daniel Poelzleithner: > > > > Zhi Yong Wu <zwu.kernel <at> gmail.com> writes: > > > > > Ping ^ 7 > > > > > > > > I'm following this patch now for quite some time and I have to say that > > > > this thread+patch is one of the most disappointing experiences I had > > > > with kernel development. > > > > > > > > I can't understand why such a patch is simply ignored from the > > > > maintainers > > > > of the subsystem, no comment, no review, no checkin. > > > > > > I always wanted to try this one out, but never got around doing it. > > > > > > I really like the general approach of it to put the general stuff into VFS > > > and only the special stuff into filesystems like BTRFS. > > > > And that's the core issue here: there are no applications that use > > the information. i.e. it's a solution looking for a problem. > > > > I spent a lot of time reviewing and helping on this, and I made > > repeated suggestions that applications like xfs_fsr could make use > > of the information to do optimised file layout during > > defragmentation, but nothing like that has ever been implemented. > > > > So, really, until there is an application that actually demonstrates > > the usefulness of the specific information that is tracked and > > exported, we can't verify that the code as it stands is actually > > useful. We can verify that the code doesn't have problems, but we > > can't verify whether it is fit for purpose because it currently has > > no purpose.... > > So this needs an example implementation for one filesystem? > > I thought there is one for BTRFS. The tracking of the "hot data" was implemented for both btrfs and XFS. There isn't a *consumer* of that data, however, and that's the missing piece of the picture. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- 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
