On 9/27/23, Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > On Wed, 27 Sept 2023 at 14:06, Mateusz Guzik <mjguzik@xxxxxxxxx> wrote: >> >> I think you attached the wrong file, it has next to no changes and in >> particular nothing for fd lookup. > > The fd lookup is already safe. > > It already does the whole "double-check the file pointer after doing > the increment" for other reasons - namely the whole "oh, the file > table can be re-allocated under us" thing. > > So the fd lookup needs rcu, but it does all the checks to make it all > work with SLAB_TYPESAFE_BY_RCU. > Indeed, nice. Sorry, I discounted the patch after not seeing anything for fd and file_free_rcu still being there. Looked like a WIP. I'm going to give it a spin tomorrow along with some benching. -- Mateusz Guzik <mjguzik gmail.com>
