On Wed, Mar 2, 2022 at 8:59 AM Dave Chinner <david@xxxxxxxxxxxxx> wrote: > > On Tue, Mar 01, 2022 at 08:42:15PM +0200, Amir Goldstein wrote: > > Miklos, > > > > Following your feedback on v2 [1], I moved the iostats to per-sb. > > > > Thanks, > > Amir. > > > > [1] https://lore.kernel.org/linux-unionfs/20220228113910.1727819-1-amir73il@xxxxxxxxx/ > > > > Changes since v2: > > - Change from per-mount to per-sb io stats (szeredi) > > - Avoid percpu loop when reading mountstats (dchinner) > > > > Changes since v1: > > - Opt-in for per-mount io stats for overlayfs and fuse > > Why make it optional only for specific filesystem types? Shouldn't > every superblock capture these stats and export them in exactly the > same place? > I am not sure what you are asking. Any filesystem can opt-in to get those generic io stats. This is exactly the same as any filesystem can already opt-in for fs specific io stats using the s_op->show_stats() vfs op. All I did was to provide a generic implementation. The generic io stats are collected and displayed for all filesystems the same way. I only included patches for overlayfs and fuse to opt-in for generic io stats, because I think those stats should be reported unconditionally (to mount options) for fuse/overlayfs and I hope that Miklos agrees with me. If there is wide consensus that all filesystems should have those stats unconditionally (to mount options), then I can post another patch to make the behavior not opt-in, but I have a feeling that this discussion will take longer than I care to wait before enabling the io stats for fuse/overlayfs, so I would rather start with enabling io stats for fuse/overlayfs and decide about the rest later. How would you prefer the io stats behavior for xfs (or any fs) to be? Unconditional to mount options? Opt-in with mount option? (suggest name please) Opt-in/out with mount options and default with Kconfig/sysfs tunable? Anything else? Thanks, Amir.
