On Sat, 12 Dec 2020 14:50:22 -0800 Jakub Kicinski wrote: > > @@ -6731,6 +6790,7 @@ void napi_disable(struct napi_struct *n) > > msleep(1); > > > > hrtimer_cancel(&n->timer); > > + napi_kthread_stop(n); > > I'm surprised that we stop the thread on napi_disable() but there is no > start/create in napi_enable(). NAPIs can (and do get) disabled and > enabled again. But that'd make your code crash with many popular > drivers if you tried to change rings with threaded napi enabled so I > feel like I must be missing something..
Ah, not crash, 'cause the flag gets cleared. Is it intentional that any changes that disable NAPIs cause us to go back to non-threaded NAPI? I think I had the "threaded" setting stored in struct netdevice in my patches, is there a reason not to do that? In fact your patches may _require_ the device to be up to enable threaded NAPI if NAPIs are allocated in open.
