On Sun, 11 Dec 2011 16:44:29 +0200, "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > On Thu, Dec 08, 2011 at 03:07:29PM +1030, Rusty Russell wrote: > > On Wed, 7 Dec 2011 17:21:22 +0200, "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > > > Fix theoretical races related to refill work: > > > 1. After napi is disabled by ndo_stop, refill work > > > can run and re-enable it. > > > 2. Refill can reschedule itself, if this happens > > > it can run after cancel_delayed_work_sync, > > > and will access device after it is destroyed. > > > > > > As a solution, add flags to track napi state and > > > to disable refill, and toggle them on start, stop > > > and remove; check these flags on refill. > > > > Why isn't a "dont-readd" flag sufficient? > > > > Cheers, > > Rusty. > > I started with that, but here's the problem I wanted to > address: > > - we run out of descriptors and schedule refill work > - ndo_close runs > - refill work runs > - ndo_open runs (s/ndo_close/ndo_stop/) You don't think we should do any refills on a closed device? If so, we simply move the refill-stop code into ndo_stop (aka virtnet_close), and the refill-start code into ndo_open (aka. virtnet_open). Right? Orthogonally, the refill-stop code is still buggy, as you noted. And for self-rearming timers the pattern I've always used is a flag. Or am I being obtuse again? :) Rusty. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
