drivers/net/ethernet/microsoft/mana/mana_en.c | 38 +++++++++++++++++-- 1 file changed, 34 insertions(+), 4 deletions(-)
When unloading the MANA driver, mana_dealloc_queues() waits for the MANA
hardware to complete any inflight packets and set the pending send count
to zero. But if the hardware has failed, mana_dealloc_queues()
could wait forever.
Fix this by adding a timeout to the wait. Set the timeout to 120 seconds,
which is a somewhat arbitrary value that is more than long enough for
functional hardware to complete any sends.
Cc: stable@vger.kernel.org
Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)")
Signed-off-by: Souradeep Chakrabarti <schakrabarti@linux.microsoft.com>
---
V5 -> V6:
* Added pcie_flr to reset the pci after timeout.
* Fixed the position of changelog.
* Removed unused variable like cq.
V4 -> V5:
* Added fixes tag
* Changed the usleep_range from static to incremental value.
* Initialized timeout in the begining.
V3 -> V4:
* Removed the unnecessary braces from mana_dealloc_queues().
V2 -> V3:
* Removed the unnecessary braces from mana_dealloc_queues().
V1 -> V2:
* Added net branch
* Removed the typecasting to (struct mana_context*) of void pointer
* Repositioned timeout variable in mana_dealloc_queues()
* Repositioned vf_unload_timeout in mana_context struct, to utilise the
6 bytes hole
---
drivers/net/ethernet/microsoft/mana/mana_en.c | 38 +++++++++++++++++--
1 file changed, 34 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index a499e460594b..ea039e2d4c4b 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -8,6 +8,7 @@
#include <linux/ethtool.h>
#include <linux/filter.h>
#include <linux/mm.h>
+#include <linux/pci.h>
#include <net/checksum.h>
#include <net/ip6_checksum.h>
@@ -2345,9 +2346,12 @@ int mana_attach(struct net_device *ndev)
static int mana_dealloc_queues(struct net_device *ndev)
{
struct mana_port_context *apc = netdev_priv(ndev);
+ unsigned long timeout = jiffies + 120 * HZ;
struct gdma_dev *gd = apc->ac->gdma_dev;
struct mana_txq *txq;
+ struct sk_buff *skb;
int i, err;
+ u32 tsleep;
if (apc->port_is_up)
return -EINVAL;
@@ -2363,15 +2367,41 @@ static int mana_dealloc_queues(struct net_device *ndev)
* to false, but it doesn't matter since mana_start_xmit() drops any
* new packets due to apc->port_is_up being false.
*
- * Drain all the in-flight TX packets
+ * Drain all the in-flight TX packets.
+ * A timeout of 120 seconds for all the queues is used.
+ * This will break the while loop when h/w is not responding.
+ * This value of 120 has been decided here considering max
+ * number of queues.
*/
+
for (i = 0; i < apc->num_queues; i++) {
txq = &apc->tx_qp[i].txq;
-
- while (atomic_read(&txq->pending_sends) > 0)
- usleep_range(1000, 2000);
+ tsleep = 1000;
+ while (atomic_read(&txq->pending_sends) > 0 &&
+ time_before(jiffies, timeout)) {
+ usleep_range(tsleep, tsleep + 1000);
+ tsleep <<= 1;
+ }
+ if (atomic_read(&txq->pending_sends)) {
+ err = pcie_flr(to_pci_dev(gd->gdma_context->dev));
+ if (err) {
+ netdev_err(ndev, "flr failed %d with %d pkts pending in txq %u\n",
+ err, atomic_read(&txq->pending_sends),
+ txq->gdma_txq_id);
+ }
+ break;
+ }
}
+ for (i = 0; i < apc->num_queues; i++) {
+ txq = &apc->tx_qp[i].txq;
+ while (atomic_read(&txq->pending_sends)) {
+ skb = skb_dequeue(&txq->pending_skbs);
+ mana_unmap_skb(skb, apc);
+ dev_consume_skb_any(skb);
+ 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.
*/
--
2.34.1On Wed, Jul 26, 2023 at 06:15:36AM -0700, Souradeep Chakrabarti wrote:
> When unloading the MANA driver, mana_dealloc_queues() waits for the MANA
> hardware to complete any inflight packets and set the pending send count
> to zero. But if the hardware has failed, mana_dealloc_queues()
> could wait forever.
>
> Fix this by adding a timeout to the wait. Set the timeout to 120 seconds,
> which is a somewhat arbitrary value that is more than long enough for
> functional hardware to complete any sends.
>
> Cc: stable@vger.kernel.org
> Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)")
>
> Signed-off-by: Souradeep Chakrabarti <schakrabarti@linux.microsoft.com>
Hi Souradeep. The subject line of this patch seems to be cut off half
way.
Thanks,
Wei.
在 2023/7/26 21:15, Souradeep Chakrabarti 写道:
> When unloading the MANA driver, mana_dealloc_queues() waits for the MANA
> hardware to complete any inflight packets and set the pending send count
> to zero. But if the hardware has failed, mana_dealloc_queues()
> could wait forever.
>
> Fix this by adding a timeout to the wait. Set the timeout to 120 seconds,
> which is a somewhat arbitrary value that is more than long enough for
> functional hardware to complete any sends.
>
> Cc: stable@vger.kernel.org
> Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)")
>
> Signed-off-by: Souradeep Chakrabarti <schakrabarti@linux.microsoft.com>
> ---
> V5 -> V6:
> * Added pcie_flr to reset the pci after timeout.
> * Fixed the position of changelog.
> * Removed unused variable like cq.
>
> V4 -> V5:
> * Added fixes tag
> * Changed the usleep_range from static to incremental value.
> * Initialized timeout in the begining.
>
> V3 -> V4:
> * Removed the unnecessary braces from mana_dealloc_queues().
>
> V2 -> V3:
> * Removed the unnecessary braces from mana_dealloc_queues().
>
> V1 -> V2:
> * Added net branch
> * Removed the typecasting to (struct mana_context*) of void pointer
> * Repositioned timeout variable in mana_dealloc_queues()
> * Repositioned vf_unload_timeout in mana_context struct, to utilise the
> 6 bytes hole
> ---
> drivers/net/ethernet/microsoft/mana/mana_en.c | 38 +++++++++++++++++--
> 1 file changed, 34 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
> index a499e460594b..ea039e2d4c4b 100644
> --- a/drivers/net/ethernet/microsoft/mana/mana_en.c
> +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
> @@ -8,6 +8,7 @@
> #include <linux/ethtool.h>
> #include <linux/filter.h>
> #include <linux/mm.h>
> +#include <linux/pci.h>
>
> #include <net/checksum.h>
> #include <net/ip6_checksum.h>
> @@ -2345,9 +2346,12 @@ int mana_attach(struct net_device *ndev)
> static int mana_dealloc_queues(struct net_device *ndev)
> {
> struct mana_port_context *apc = netdev_priv(ndev);
> + unsigned long timeout = jiffies + 120 * HZ;
> struct gdma_dev *gd = apc->ac->gdma_dev;
> struct mana_txq *txq;
> + struct sk_buff *skb;
> int i, err;
> + u32 tsleep;
>
> if (apc->port_is_up)
> return -EINVAL;
> @@ -2363,15 +2367,41 @@ static int mana_dealloc_queues(struct net_device *ndev)
> * to false, but it doesn't matter since mana_start_xmit() drops any
> * new packets due to apc->port_is_up being false.
> *
> - * Drain all the in-flight TX packets
> + * Drain all the in-flight TX packets.
> + * A timeout of 120 seconds for all the queues is used.
> + * This will break the while loop when h/w is not responding.
> + * This value of 120 has been decided here considering max
> + * number of queues.
> */
> +
> for (i = 0; i < apc->num_queues; i++) {
> txq = &apc->tx_qp[i].txq;
> -
> - while (atomic_read(&txq->pending_sends) > 0)
> - usleep_range(1000, 2000);
> + tsleep = 1000;
> + while (atomic_read(&txq->pending_sends) > 0 &&
> + time_before(jiffies, timeout)) {
> + usleep_range(tsleep, tsleep + 1000);
> + tsleep <<= 1;
> + }
> + if (atomic_read(&txq->pending_sends)) {
> + err = pcie_flr(to_pci_dev(gd->gdma_context->dev));
> + if (err) {
> + netdev_err(ndev, "flr failed %d with %d pkts pending in txq %u\n",
> + err, atomic_read(&txq->pending_sends),
> + txq->gdma_txq_id);
> + }
> + break;
> + }
> }
>
> + for (i = 0; i < apc->num_queues; i++) {
> + txq = &apc->tx_qp[i].txq;
> + while (atomic_read(&txq->pending_sends)) {
> + skb = skb_dequeue(&txq->pending_skbs);
> + mana_unmap_skb(skb, apc);
> + dev_consume_skb_any(skb);
> + atomic_sub(1, &txq->pending_sends);
> + }
If I get this commit correctly, txq->pending_sends should be equal to
the length of txq->pending_skbs?
If yes, can we only handle the pending_skbs?
the above snippet can be changed to as below? So the performance is better?
"
while ((skb = skb_dequeue(&txq->pending_skbs))) {
mana_unmap_skb(skb, apc);
dev_consume_skb_any(skb);
}
atomic_set(&txq->pending_sends, 0);
"
Zhu Yanjun
> + }
> /* 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.
> */
On Thu, Jul 27, 2023 at 9:07 AM Zhu Yanjun <yanjun.zhu@linux.dev> wrote:
>
> 在 2023/7/26 21:15, Souradeep Chakrabarti 写道:
> > When unloading the MANA driver, mana_dealloc_queues() waits for the MANA
> > hardware to complete any inflight packets and set the pending send count
> > to zero. But if the hardware has failed, mana_dealloc_queues()
> > could wait forever.
> >
> > Fix this by adding a timeout to the wait. Set the timeout to 120 seconds,
> > which is a somewhat arbitrary value that is more than long enough for
> > functional hardware to complete any sends.
> >
> > Cc: stable@vger.kernel.org
> > Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)")
> >
> > Signed-off-by: Souradeep Chakrabarti <schakrabarti@linux.microsoft.com>
> > ---
> > V5 -> V6:
> > * Added pcie_flr to reset the pci after timeout.
> > * Fixed the position of changelog.
> > * Removed unused variable like cq.
> >
> > V4 -> V5:
> > * Added fixes tag
> > * Changed the usleep_range from static to incremental value.
> > * Initialized timeout in the begining.
> >
> > V3 -> V4:
> > * Removed the unnecessary braces from mana_dealloc_queues().
> >
> > V2 -> V3:
> > * Removed the unnecessary braces from mana_dealloc_queues().
> >
> > V1 -> V2:
> > * Added net branch
> > * Removed the typecasting to (struct mana_context*) of void pointer
> > * Repositioned timeout variable in mana_dealloc_queues()
> > * Repositioned vf_unload_timeout in mana_context struct, to utilise the
> > 6 bytes hole
> > ---
> > drivers/net/ethernet/microsoft/mana/mana_en.c | 38 +++++++++++++++++--
> > 1 file changed, 34 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
> > index a499e460594b..ea039e2d4c4b 100644
> > --- a/drivers/net/ethernet/microsoft/mana/mana_en.c
> > +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
> > @@ -8,6 +8,7 @@
> > #include <linux/ethtool.h>
> > #include <linux/filter.h>
> > #include <linux/mm.h>
> > +#include <linux/pci.h>
> >
> > #include <net/checksum.h>
> > #include <net/ip6_checksum.h>
> > @@ -2345,9 +2346,12 @@ int mana_attach(struct net_device *ndev)
> > static int mana_dealloc_queues(struct net_device *ndev)
> > {
> > struct mana_port_context *apc = netdev_priv(ndev);
> > + unsigned long timeout = jiffies + 120 * HZ;
> > struct gdma_dev *gd = apc->ac->gdma_dev;
> > struct mana_txq *txq;
> > + struct sk_buff *skb;
> > int i, err;
> > + u32 tsleep;
> >
> > if (apc->port_is_up)
> > return -EINVAL;
> > @@ -2363,15 +2367,41 @@ static int mana_dealloc_queues(struct net_device *ndev)
> > * to false, but it doesn't matter since mana_start_xmit() drops any
> > * new packets due to apc->port_is_up being false.
> > *
> > - * Drain all the in-flight TX packets
> > + * Drain all the in-flight TX packets.
> > + * A timeout of 120 seconds for all the queues is used.
> > + * This will break the while loop when h/w is not responding.
> > + * This value of 120 has been decided here considering max
> > + * number of queues.
> > */
> > +
> > for (i = 0; i < apc->num_queues; i++) {
> > txq = &apc->tx_qp[i].txq;
> > -
> > - while (atomic_read(&txq->pending_sends) > 0)
> > - usleep_range(1000, 2000);
> > + tsleep = 1000;
> > + while (atomic_read(&txq->pending_sends) > 0 &&
> > + time_before(jiffies, timeout)) {
> > + usleep_range(tsleep, tsleep + 1000);
> > + tsleep <<= 1;
> > + }
> > + if (atomic_read(&txq->pending_sends)) {
> > + err = pcie_flr(to_pci_dev(gd->gdma_context->dev));
> > + if (err) {
> > + netdev_err(ndev, "flr failed %d with %d pkts pending in txq %u\n",
> > + err, atomic_read(&txq->pending_sends),
> > + txq->gdma_txq_id);
> > + }
> > + break;
> > + }
> > }
> >
> > + for (i = 0; i < apc->num_queues; i++) {
> > + txq = &apc->tx_qp[i].txq;
> > + while (atomic_read(&txq->pending_sends)) {
> > + skb = skb_dequeue(&txq->pending_skbs);
> > + mana_unmap_skb(skb, apc);
> > + dev_consume_skb_any(skb);
> > + atomic_sub(1, &txq->pending_sends);
> > + }
> If I get this commit correctly, txq->pending_sends should be equal to
> the length of txq->pending_skbs?
>
> If yes, can we only handle the pending_skbs?
>
> the above snippet can be changed to as below? So the performance is better?
> "
> while ((skb = skb_dequeue(&txq->pending_skbs))) {
> mana_unmap_skb(skb, apc);
> dev_consume_skb_any(skb);
> }
> atomic_set(&txq->pending_sends, 0);
> "
>
> Zhu Yanjun
Yes, we can do that, thanks for pointing. Will take care of it in next version.
>
> > + }
> > /* 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.
> > */
>
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