On 8/28/23 13:00, Boris Brezillon wrote: > On Sun, 27 Aug 2023 20:54:42 +0300 > Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx> wrote: > >> Use kref helper for vmap_use_count to make refcounting consistent with >> pages_use_count and pages_pin_count that use kref. This will allow to >> optimize unlocked vmappings by skipping reservation locking if refcnt > 1. > > The core is taking the resv lock before calling ->v[un]map(), so > switching to a kref sounds a bit premature/useless, unless there are > plans to delegate the locking to the drivers. The only thing it brings > is standard overflow/underflow checks. Not really sure it's worth > transitioning to a kref for this field until we have a real use case. The overflow checks worth transitioning. I'll mention them in the commit message for v16. -- Best regards, Dmitry
