[$] Improving FUSE writeback performance

In a combined filesystem and memory-management session at the 2025 Linux Storage, Filesystem, Memory Management, and BPF Summit (LSFMM+BPF), Joanne Koong led a discussion on improving the writeback performance for the Filesystem in Userspace (FUSE) layer. Writeback is how data that is written to the filesystem is actually flushed to the disk; it is the process of writing dirty pages from the page cache to storage. The current FUSE implementation allocates unmovable memory, then copies the dirty data to it before initiating writeback, which is slow; Koong wanted to change that behavior. Since the session, she has posted a patch set that has been applied by FUSE maintainer Miklos Szeredi.