xen-netback: correctly schedule rate-limited queues
Add a flag to indicate if a queue is rate-limited. Test the flag in
NAPI poll handler and avoid rescheduling the queue if true, otherwise
we risk locking up the host. The rescheduling will be done in the
timer callback function.
Reported-by: Jean-Louis Dupond <jean-louis@dupond.be>
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Tested-by: Jean-Louis Dupond <jean-louis@dupond.be>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index 8397f6c..e322a86 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -106,7 +106,11 @@ static int xenvif_poll(struct napi_struct *napi, int budget)
if (work_done < budget) {
napi_complete_done(napi, work_done);
- xenvif_napi_schedule_or_enable_events(queue);
+ /* If the queue is rate-limited, it shall be
+ * rescheduled in the timer callback.
+ */
+ if (likely(!queue->rate_limited))
+ xenvif_napi_schedule_or_enable_events(queue);
}
return work_done;