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authorDavid Vrabel <david.vrabel@citrix.com>2015-02-02 16:57:51 +0000
committerDavid S. Miller <davem@davemloft.net>2015-02-02 19:39:04 -0800
commit42b5212fee4f57907e9415b18fe19c13e65574bc (patch)
tree3fb44adcfd6de16f9e3ceddcf46d7a2c9c54532c
parent5a2e87b16875f9b83b7e9494cf1fce8e17dc764a (diff)
xen-netback: stop the guest rx thread after a fatal error
After commit e9d8b2c2968499c1f96563e6522c56958d5a1d0d (xen-netback: disable rogue vif in kthread context), a fatal (protocol) error would leave the guest Rx thread spinning, wasting CPU time. Commit ecf08d2dbb96d5a4b4bcc53a39e8d29cc8fef02e (xen-netback: reintroduce guest Rx stall detection) made this even worse by removing a cond_resched() from this path. Since a fatal error is non-recoverable, just allow the guest Rx thread to exit. This requires taking additional refs to the task so the thread exiting early is handled safely. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reported-by: Julien Grall <julien.grall@linaro.org> Tested-by: Julien Grall <julien.grall@linaro.org> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/xen-netback/interface.c2
-rw-r--r--drivers/net/xen-netback/netback.c3
2 files changed, 3 insertions, 2 deletions
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index 9259a732e8a..037f74f0fcf 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -578,6 +578,7 @@ int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
goto err_rx_unbind;
}
queue->task = task;
+ get_task_struct(task);
task = kthread_create(xenvif_dealloc_kthread,
(void *)queue, "%s-dealloc", queue->name);
@@ -634,6 +635,7 @@ void xenvif_disconnect(struct xenvif *vif)
if (queue->task) {
kthread_stop(queue->task);
+ put_task_struct(queue->task);
queue->task = NULL;
}
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 908e65e9b82..c8ce701a7ef 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -2109,8 +2109,7 @@ int xenvif_kthread_guest_rx(void *data)
*/
if (unlikely(vif->disabled && queue->id == 0)) {
xenvif_carrier_off(vif);
- xenvif_rx_queue_purge(queue);
- continue;
+ break;
}
if (!skb_queue_empty(&queue->rx_queue))