From: Kameron Carr <[email protected]> Sent: Thursday, August 6, 2026 1:06 PM > > On Friday, July 31, 2026 8:47 AM, Michael Kelley wrote: > > From: Kameron Carr <[email protected]> Sent: Thursday, July > > 30, 2026 4:34 PM
[snip] > > > diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c > > > index 59e95341f9b1e..1192929d93a86 100644 > > > --- a/drivers/net/hyperv/netvsc.c > > > +++ b/drivers/net/hyperv/netvsc.c > > > @@ -28,6 +28,8 @@ > > > #include "hyperv_net.h" > > > #include "netvsc_trace.h" > > > > > > +static struct workqueue_struct *netvsc_wq; > > > + > > > > Does netvsc needs its own workqueue to do the "free" operation, > > or would the system default workqueue (system_dfl_wq) be just > > as good? At first glance, the system_dfl_wq seems like it would work, > > since netvsc free operations are rare and don't have any strict > > latency requirements. But I'm far from being expect in workqueues, > > and there could be subtleties I'm not aware of. > > I have to drain the work queue before module unload. > Currently this is handled by destroying the queue. > > Originally, I tried using a system wide queue, but I saw that there are > compile time warnings, __warn_flushing_systemwide_wq(), which state: > "WARNING: Flushing system-wide workqueues will be prohibited in near > future." > OK, that's make good sense. There is indeed a subtlety. :-) I had not ever thought about the problem of unloading a module if a function in the module is being run by a workqueue. Thanks, Michael
