On Thu, 25 Jan 2024 17:59:40 -0800 Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > I tried to use kernfs when doing a lot of this and I had issues. I > > don't remember what those were, but I can revisit it. > > You might, as kernfs makes it so that the filesystem structures are > created on demand, when accessed, and then removed when memory pressure > happens. That's what sysfs and configfs and cgroups use quite > successfully. kernfs doesn't look trivial and I can't find any documentation on how to use it. Should there be work to move debugfs over to kernfs? I could look at it too, but as tracefs, and more specifically eventfs, has 10s of thousands of files, I'm very concerned about meta data size. Currently eventfs keeps a data structure for every directory, but for the files, it only keeps an array of names and callbacks. When a directory is registered, it lists the files it needs. eventfs is specific that the number of files a directory has is always constant, and files will not be removed or added once a directory is created. This way, the information on how a file is created is done via a callback that was registered when the directory was created. For this use case, I don't think kernfs could be used. But I would still like to talk about what I'm trying to accomplish, and perhaps see if there's work that can be done to consolidate what is out there. -- Steve
