From: Vineeth Remanan Pillai <vinee...@amazon.com> Date: Thu, 19 Jan 2017 08:35:39 -0800
> From: Vineeth Remanan Pillai <vinee...@amazon.com> > > During an OOM scenario, request slots could not be created as skb > allocation fails. So the netback cannot pass in packets and netfront > wrongly assumes that there is no more work to be done and it disables > polling. This causes Rx to stall. > > The issue is with the retry logic which schedules the timer if the > created slots are less than NET_RX_SLOTS_MIN. The count of new request > slots to be pushed are calculated as a difference between new req_prod > and rsp_cons which could be more than the actual slots, if there are > unconsumed responses. > > The fix is to calculate the count of newly created slots as the > difference between new req_prod and old req_prod. > > Signed-off-by: Vineeth Remanan Pillai <vinee...@amazon.com> > Reviewed-by: Juergen Gross <jgr...@suse.com> > --- > Changes in v2: > - Removed the old implementation of enabling polling on > skb allocation error. > - Corrected the refill timer logic to schedule when newly > created slots since last push is less than NET_RX_SLOTS_MIN. Applied.
