On Thu, Oct 10, 2024 at 02:27:33PM +0200, Javier Gonzalez wrote: [full quote snipped, it would be really helpful to only quote what you actuall reference per the usual email rules] >> Data placement by-file is based on that the lifetime of a file's data >> blocks are strongly correlated. When a file is deleted, all its blocks >> will be reclaimable at that point. This requires knowledge about the >> data placement buckets and works really well without any hints >> provided. > > But we need hints to put files together. I believe you do this already, > as no placement protocol gives you unlimited separation. The per-file temperature hints do a reasonable job for that. A fully developed version of the separate write streams submitted by Kanchan would probably do even better, but for now the per-file hints seem to be enough. > Maybe you can post some patches on the parts dedicated to the VFS level > and user-space API (syscall or uring)? It's just using the existing temperature hints.