On Wed, Mar 5, 2025 at 3:19 AM David Laight <david.laight.linux@xxxxxxxxx> wrote: > Have you looked at the problem caused by epoll() ? > The epoll code has a 'hidden' extra reference to the fd. > This doesn't usualy matter, but some of the driver callbacks add and > remove an extra reference - which doesn't work well if fput() has > just decremented it to zero. > > The fput code might need to do a 'decrement not one' so that the > epoll tidyup can be done while the refcount is still one. > > That would save the extra atomic pair that (IIRC) got added into > the epoll callback code. > > Thoughts? I am not aware of this problem and don't have particular interest in looking at it either, sorry. Good thing you are free to make the case to Christian. :) -- Mateusz Guzik <mjguzik gmail.com>
