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authorWei Liu <wei.liu2@citrix.com>2017-06-21 10:21:22 +0100
committerDavid S. Miller <davem@davemloft.net>2017-06-22 11:15:42 -0400
commitdfa523ae9f2542bee4cddaea37b3be3e157f6e6b (patch)
tree3c31b603c04bad0bb51c19305488cc12140ff7cb /drivers/net/xen-netback/netback.c
parentveth: Be more robust on network device creation when no attributes (diff)
downloadlinux-dev-dfa523ae9f2542bee4cddaea37b3be3e157f6e6b.tar.xz
linux-dev-dfa523ae9f2542bee4cddaea37b3be3e157f6e6b.zip
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>
Diffstat (limited to 'drivers/net/xen-netback/netback.c')
-rw-r--r--drivers/net/xen-netback/netback.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 602d408fa25e..5042ff8d449a 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -180,6 +180,7 @@ 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)
@@ -686,8 +687,10 @@ 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)) {
@@ -702,6 +705,7 @@ 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;
}