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/netback.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/net/xen-netback/netback.c') diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 1049c34e7d43..72ee1c305cc4 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -687,6 +687,7 @@ static void tx_add_credit(struct xenvif_queue *queue) max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */ queue->remaining_credit = min(max_credit, max_burst); + queue->rate_limited = false; } void xenvif_tx_credit_callback(unsigned long data) @@ -1184,8 +1185,10 @@ static bool tx_credit_exceeded(struct xenvif_queue *queue, unsigned size) msecs_to_jiffies(queue->credit_usec / 1000); /* Timer could already be pending in rare cases. */ - if (timer_pending(&queue->credit_timeout)) + if (timer_pending(&queue->credit_timeout)) { + queue->rate_limited = true; return true; + } /* Passed the point where we can replenish credit? */ if (time_after_eq64(now, next_credit)) { @@ -1200,6 +1203,7 @@ static bool tx_credit_exceeded(struct xenvif_queue *queue, unsigned size) mod_timer(&queue->credit_timeout, next_credit); queue->credit_window_start = next_credit; + queue->rate_limited = true; return true; } -- cgit v1.2.3