On Tue, Mar 03, 2020 at 03:21:47PM +0100, Michael Stapelberg wrote: > Find attached trace.log (cat /sys/kernel/debug/tracing/trace) and > fuse-debug.log (FUSE daemon with timestamps). > > Does that tell you something, or do we need more data? (If so, how?) This is likely the culprit. .... 1319822.406198: balance_dirty_pages: ... bdi_dirty=68 dirty_ratelimit=28 ... For whatever reason, bdp calculated that the dirty throttling threshold for the fuse device is 28 pages which is extremely low. Need to track down how that number came to be. I'm afraid from here on it'd mostly be reading source code and sprinkling printks around but the debugging really comes down to figuring out how we ended up with 68 and 28. Thanks. -- tejun