From 7c37101cd650d12bf124398eb26ba7eefb235029 Mon Sep 17 00:00:00 2001 From: Wei Liu Date: Wed, 21 Jun 2017 10:21:22 +0100 Subject: xen-netback: correctly schedule rate-limited queues [ Upstream commit dfa523ae9f2542bee4cddaea37b3be3e157f6e6b ] 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 Signed-off-by: Wei Liu Tested-by: Jean-Louis Dupond Reviewed-by: Paul Durrant Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/xen-netback/interface.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/net/xen-netback/interface.c') diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index e7bd63eb2876..60b26f32d31d 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -105,7 +105,11 @@ static int xenvif_poll(struct napi_struct *napi, int budget) if (work_done < budget) { napi_complete(napi); - 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; -- cgit v1.2.3