Hello, Michael Kelly, le lun. 09 mars 2026 20:11:45 +0000, a ecrit: > The fundamental problem is that ext2fs, being unprivileged, cannot allocate > memory in order to allow other memory to be released.
That's a concern indeed. ext2fs could be made privileged, but at the same time we don't necessarily want to leak too much privilege onto programs that make it do things. Mike Kelly, le lun. 09 mars 2026 22:04:19 +0000, a ecrit: > I've read parts of the paper written regarding porting Hurd to L4 and the > proposal to split user memory into guaranteed and pageable portions. Actually we already have this supported, through the wired pages. But what kind of memory does ext2fs need to allocate to release more memory? Ideally the writeback path would not need additional memory at all, or have pre-reserved memory that it can use. If that memory gets swapped-out it's a concern of course, we could make root-owned ext2fs wire it to avoid the issue. > Might it make the resident set for rumpdisk smaller too if parts of that code > don't actually get used by Hurd? I guess the problem with rumpdisk is rather that we have not actually looked at its memory pool allocations, and have left it at very large values which don't make sense for a userland process. Samuel
