* [PATCH net 0/3] ibmvnic: correctly call NAPI APIs
@ 2021-04-14 7:46 Lijun Pan
2021-04-14 7:46 ` [PATCH net 1/3] ibmvnic: avoid calling napi_disable() twice Lijun Pan
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: Lijun Pan @ 2021-04-14 7:46 UTC (permalink / raw)
To: netdev; +Cc: Lijun Pan
This series correct some misuse of NAPI APIs in the driver.
Lijun Pan (3):
ibmvnic: avoid calling napi_disable() twice
ibmvnic: remove duplicate napi_schedule call in do_reset function
ibmvnic: remove duplicate napi_schedule call in open function
drivers/net/ethernet/ibm/ibmvnic.c | 14 ++------------
1 file changed, 2 insertions(+), 12 deletions(-)
--
2.23.0
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH net 1/3] ibmvnic: avoid calling napi_disable() twice
2021-04-14 7:46 [PATCH net 0/3] ibmvnic: correctly call NAPI APIs Lijun Pan
@ 2021-04-14 7:46 ` Lijun Pan
2021-04-14 7:46 ` [PATCH net 2/3] ibmvnic: remove duplicate napi_schedule call in do_reset function Lijun Pan
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Lijun Pan @ 2021-04-14 7:46 UTC (permalink / raw)
To: netdev; +Cc: Lijun Pan, Thomas Falcon
__ibmvnic_open calls napi_disable without checking whether NAPI polling
has already been disabled or not. This could cause napi_disable
being called twice, which could generate deadlock. For example,
the first napi_disable will spin until NAPI_STATE_SCHED is cleared
by napi_complete_done, then set it again.
When napi_disable is called the second time, it will loop infinitely
because no dev->poll will be running to clear NAPI_STATE_SCHED.
To prevent above scenario from happening, call ibmvnic_napi_disable()
which checks if napi is disabled or not before calling napi_disable.
Fixes: bfc32f297337 ("ibmvnic: Move resource initialization to its own routine")
Suggested-by: Thomas Falcon <tlfalcon@linux.ibm.com>
Signed-off-by: Lijun Pan <lijunp213@gmail.com>
---
drivers/net/ethernet/ibm/ibmvnic.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 110a0d0eaabb..2d27f8aa0d4b 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1149,8 +1149,7 @@ static int __ibmvnic_open(struct net_device *netdev)
rc = set_link_state(adapter, IBMVNIC_LOGICAL_LNK_UP);
if (rc) {
- for (i = 0; i < adapter->req_rx_queues; i++)
- napi_disable(&adapter->napi[i]);
+ ibmvnic_napi_disable(adapter);
release_resources(adapter);
return rc;
}
--
2.23.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH net 2/3] ibmvnic: remove duplicate napi_schedule call in do_reset function
2021-04-14 7:46 [PATCH net 0/3] ibmvnic: correctly call NAPI APIs Lijun Pan
2021-04-14 7:46 ` [PATCH net 1/3] ibmvnic: avoid calling napi_disable() twice Lijun Pan
@ 2021-04-14 7:46 ` Lijun Pan
2021-04-14 7:46 ` [PATCH net 3/3] ibmvnic: remove duplicate napi_schedule call in open function Lijun Pan
2021-04-14 20:20 ` [PATCH net 0/3] ibmvnic: correctly call NAPI APIs patchwork-bot+netdevbpf
3 siblings, 0 replies; 5+ messages in thread
From: Lijun Pan @ 2021-04-14 7:46 UTC (permalink / raw)
To: netdev; +Cc: Lijun Pan
During adapter reset, do_reset/do_hard_reset calls ibmvnic_open(),
which will calls napi_schedule if previous state is VNIC_CLOSED
(i.e, the reset case, and "ifconfig down" case). So there is no need
for do_reset to call napi_schedule again at the end of the function
though napi_schedule will neglect the request if napi is already
scheduled.
Fixes: ed651a10875f ("ibmvnic: Updated reset handling")
Signed-off-by: Lijun Pan <lijunp213@gmail.com>
---
drivers/net/ethernet/ibm/ibmvnic.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 2d27f8aa0d4b..f4bd63216672 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1921,7 +1921,7 @@ static int do_reset(struct ibmvnic_adapter *adapter,
u64 old_num_rx_queues, old_num_tx_queues;
u64 old_num_rx_slots, old_num_tx_slots;
struct net_device *netdev = adapter->netdev;
- int i, rc;
+ int rc;
netdev_dbg(adapter->netdev,
"[S:%d FOP:%d] Reset reason %d, reset_state %d\n",
@@ -2110,10 +2110,6 @@ static int do_reset(struct ibmvnic_adapter *adapter,
/* refresh device's multicast list */
ibmvnic_set_multi(netdev);
- /* kick napi */
- for (i = 0; i < adapter->req_rx_queues; i++)
- napi_schedule(&adapter->napi[i]);
-
if (adapter->reset_reason == VNIC_RESET_FAILOVER ||
adapter->reset_reason == VNIC_RESET_MOBILITY)
__netdev_notify_peers(netdev);
--
2.23.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH net 3/3] ibmvnic: remove duplicate napi_schedule call in open function
2021-04-14 7:46 [PATCH net 0/3] ibmvnic: correctly call NAPI APIs Lijun Pan
2021-04-14 7:46 ` [PATCH net 1/3] ibmvnic: avoid calling napi_disable() twice Lijun Pan
2021-04-14 7:46 ` [PATCH net 2/3] ibmvnic: remove duplicate napi_schedule call in do_reset function Lijun Pan
@ 2021-04-14 7:46 ` Lijun Pan
2021-04-14 20:20 ` [PATCH net 0/3] ibmvnic: correctly call NAPI APIs patchwork-bot+netdevbpf
3 siblings, 0 replies; 5+ messages in thread
From: Lijun Pan @ 2021-04-14 7:46 UTC (permalink / raw)
To: netdev; +Cc: Lijun Pan
Remove the unnecessary napi_schedule() call in __ibmvnic_open() since
interrupt_rx() calls napi_schedule_prep/__napi_schedule during every
receive interrupt.
Fixes: ed651a10875f ("ibmvnic: Updated reset handling")
Signed-off-by: Lijun Pan <lijunp213@gmail.com>
---
drivers/net/ethernet/ibm/ibmvnic.c | 5 -----
1 file changed, 5 deletions(-)
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index f4bd63216672..ffb2a91750c7 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1156,11 +1156,6 @@ static int __ibmvnic_open(struct net_device *netdev)
netif_tx_start_all_queues(netdev);
- if (prev_state == VNIC_CLOSED) {
- for (i = 0; i < adapter->req_rx_queues; i++)
- napi_schedule(&adapter->napi[i]);
- }
-
adapter->state = VNIC_OPEN;
return rc;
}
--
2.23.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH net 0/3] ibmvnic: correctly call NAPI APIs
2021-04-14 7:46 [PATCH net 0/3] ibmvnic: correctly call NAPI APIs Lijun Pan
` (2 preceding siblings ...)
2021-04-14 7:46 ` [PATCH net 3/3] ibmvnic: remove duplicate napi_schedule call in open function Lijun Pan
@ 2021-04-14 20:20 ` patchwork-bot+netdevbpf
3 siblings, 0 replies; 5+ messages in thread
From: patchwork-bot+netdevbpf @ 2021-04-14 20:20 UTC (permalink / raw)
To: Lijun Pan; +Cc: netdev
Hello:
This series was applied to netdev/net.git (refs/heads/master):
On Wed, 14 Apr 2021 02:46:13 -0500 you wrote:
> This series correct some misuse of NAPI APIs in the driver.
>
> Lijun Pan (3):
> ibmvnic: avoid calling napi_disable() twice
> ibmvnic: remove duplicate napi_schedule call in do_reset function
> ibmvnic: remove duplicate napi_schedule call in open function
>
> [...]
Here is the summary with links:
- [net,1/3] ibmvnic: avoid calling napi_disable() twice
https://git.kernel.org/netdev/net/c/0775ebc4cf85
- [net,2/3] ibmvnic: remove duplicate napi_schedule call in do_reset function
https://git.kernel.org/netdev/net/c/d3a6abccbd27
- [net,3/3] ibmvnic: remove duplicate napi_schedule call in open function
https://git.kernel.org/netdev/net/c/7c451f3ef676
You are awesome, thank you!
--
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2021-04-14 7:46 [PATCH net 0/3] ibmvnic: correctly call NAPI APIs Lijun Pan
2021-04-14 7:46 ` [PATCH net 1/3] ibmvnic: avoid calling napi_disable() twice Lijun Pan
2021-04-14 7:46 ` [PATCH net 2/3] ibmvnic: remove duplicate napi_schedule call in do_reset function Lijun Pan
2021-04-14 7:46 ` [PATCH net 3/3] ibmvnic: remove duplicate napi_schedule call in open function Lijun Pan
2021-04-14 20:20 ` [PATCH net 0/3] ibmvnic: correctly call NAPI APIs patchwork-bot+netdevbpf
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