On 6/26/2023 2:48 PM, souradeep chakrabarti wrote:
> From: Souradeep Chakrabarti <schakrabarti@xxxxxxxxxxxxxxxxxxx>
>
> This patch addresses the VF unload issue, where mana_dealloc_queues()
> gets stuck in infinite while loop, because of host unresponsiveness.
> It adds a timeout in the while loop, to fix it.
>
> Fixes: ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f (net: mana: Add a driver for
> Microsoft Azure Network Adapter)
> Signed-off-by: Souradeep Chakrabarti <schakrabarti@xxxxxxxxxxxxxxxxxxx>
> ---
> V2 -> V3:
> * Splitted the patch in two parts.
> * Removed the unnecessary braces from mana_dealloc_queues().
> ---
> drivers/net/ethernet/microsoft/mana/mana_en.c | 19 +++++++++++++++++--
> 1 file changed, 17 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
> index d907727c7b7a..cb5c43c3c47e 100644
> --- a/drivers/net/ethernet/microsoft/mana/mana_en.c
> +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
> @@ -2329,7 +2329,10 @@ static int mana_dealloc_queues(struct net_device *ndev)
> {
> struct mana_port_context *apc = netdev_priv(ndev);
> struct gdma_dev *gd = apc->ac->gdma_dev;
> + unsigned long timeout;
> struct mana_txq *txq;
> + struct sk_buff *skb;
> + struct mana_cq *cq;
> int i, err;
>
> if (apc->port_is_up)
> @@ -2348,13 +2351,25 @@ static int mana_dealloc_queues(struct net_device *ndev)
> *
> * Drain all the in-flight TX packets
> */
> +
> + timeout = jiffies + 120 * HZ;
> for (i = 0; i < apc->num_queues; i++) {
> txq = &apc->tx_qp[i].txq;
> -
> - while (atomic_read(&txq->pending_sends) > 0)
> + while (atomic_read(&txq->pending_sends) > 0 &&
> + time_before(jiffies, timeout))
> usleep_range(1000, 2000);
> }
>
> + for (i = 0; i < apc->num_queues; i++) {
> + txq = &apc->tx_qp[i].txq;
> + cq = &apc->tx_qp[i].tx_cq;
> + while (atomic_read(&txq->pending_sends)) {
> + skb = skb_dequeue(&txq->pending_skbs);
> + mana_unmap_skb(skb, apc);
> + napi_consume_skb(skb, cq->budget);
> + atomic_sub(1, &txq->pending_sends);
> + }
> + }
Can we combine these 2 loops into 1 something like this ?
for (i = 0; i < apc->num_queues; i++) {
txq = &apc->tx_qp[i].txq;
cq = &apc->tx_qp[i].tx_cq;
while (atomic_read(&txq->pending_sends)) {
if (time_before(jiffies, timeout)) {
usleep_range(1000, 2000);
} else {
skb = skb_dequeue(&txq->pending_skbs);
mana_unmap_skb(skb, apc);
napi_consume_skb(skb, cq->budget);
atomic_sub(1, &txq->pending_sends);
}
}
}
> /* We're 100% sure the queues can no longer be woken up, because
> * we're sure now mana_poll_tx_cq() can't be running.
> */
