On Mon, 2023-09-25 at 08:44 +1000, NeilBrown wrote: > On Sun, 24 Sep 2023, Christian Brauner wrote: > > > My initial goal was to implement multigrain timestamps on most major > > > filesystems, so we could present them to userland, and use them for > > > NFSv3, etc. > > > > If there's no clear users and workloads depending on this other than for > > the sake of NFS then we shouldn't expose this to userspace. We've tried > > this and I'm not convinced we're getting anything other than regressions > > out of it. Keep it internal and confined to the filesystem that actually > > needs this. > > > > Some NFS servers run in userspace, and they would a "clear user" of this > functionality. > Indeed. Also, all of the programs that we're concerned about breaking here (make, rsync, etc.) could benefit from proper fine-grained timestamps: Today, when they see two identical timestamps on files, these programs have to assume the worst: rsync has to do the copy, make has to update the target, etc. With a real distinguishable fine-grained timestamps, these programs would likely be more efficient and some of these unneeded operations would be avoided. -- Jeff Layton <jlayton@xxxxxxxxxx>
