Re: [PATCH] i40e: Invoke softirqs after napi_reschedule

2017-01-13 Thread David Miller 
From: Benjamin Poirier 
Date: Thu, 12 Jan 2017 17:04:14 -0800

> The following message is logged from time to time when using i40e:
> NOHZ: local_softirq_pending 08
> 
> i40e may schedule napi from a workqueue. Afterwards, softirqs are not run
> in a deterministic time frame. The problem is the same as what was
> described in commit ec13ee80145c ("virtio_net: invoke softirqs after
> __napi_schedule") and this patch applies the same fix to i40e.
> 
> Signed-off-by: Benjamin Poirier 

I hope to see this from one of Jeff's pull requests to me in the
near future.

Re: [PATCH] i40e: Invoke softirqs after napi_reschedule

2017-01-12 Thread Benjamin Poirier 
On 2017/01/12 17:15, Eric Dumazet wrote:
> On Thu, 2017-01-12 at 17:04 -0800, Benjamin Poirier wrote:
> > The following message is logged from time to time when using i40e:
> > NOHZ: local_softirq_pending 08
> > 
> > i40e may schedule napi from a workqueue. Afterwards, softirqs are not run
> > in a deterministic time frame. The problem is the same as what was
> > described in commit ec13ee80145c ("virtio_net: invoke softirqs after
> > __napi_schedule") and this patch applies the same fix to i40e.
> 
> Yes, I believe mlx4 has a similar problem in mlx4_en_recover_from_oom()

Indeed, I was going to send a patch for mlx4 after this one is accepted.

Re: [PATCH] i40e: Invoke softirqs after napi_reschedule

2017-01-12 Thread Eric Dumazet 
On Thu, 2017-01-12 at 17:04 -0800, Benjamin Poirier wrote:
> The following message is logged from time to time when using i40e:
> NOHZ: local_softirq_pending 08
> 
> i40e may schedule napi from a workqueue. Afterwards, softirqs are not run
> in a deterministic time frame. The problem is the same as what was
> described in commit ec13ee80145c ("virtio_net: invoke softirqs after
> __napi_schedule") and this patch applies the same fix to i40e.

Yes, I believe mlx4 has a similar problem in mlx4_en_recover_from_oom()

[PATCH] i40e: Invoke softirqs after napi_reschedule

2017-01-12 Thread Benjamin Poirier 
The following message is logged from time to time when using i40e:
NOHZ: local_softirq_pending 08

i40e may schedule napi from a workqueue. Afterwards, softirqs are not run
in a deterministic time frame. The problem is the same as what was
described in commit ec13ee80145c ("virtio_net: invoke softirqs after
__napi_schedule") and this patch applies the same fix to i40e.

Signed-off-by: Benjamin Poirier 
---
 drivers/net/ethernet/intel/i40e/i40e_main.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c 
b/drivers/net/ethernet/intel/i40e/i40e_main.c
index ad4cf63..d65488c 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -4621,8 +4621,10 @@ static void i40e_detect_recover_hung_queue(int q_idx, 
struct i40e_vsi *vsi)
 */
if ((!tx_pending_hw) && i40e_get_tx_pending(tx_ring, true) &&
(!(val & I40E_PFINT_DYN_CTLN_INTENA_MASK))) {
+   local_bh_disable();
if (napi_reschedule(_ring->q_vector->napi))
tx_ring->tx_stats.tx_lost_interrupt++;
+   local_bh_enable();
}
 }
 
-- 
2.10.2