This is a note to let you know that I've just added the patch titled
i40e: Do not enable NAPI on q_vectors that have no rings
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
i40e-do-not-enable-napi-on-q_vectors-that-have-no-rings.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Thu Dec 21 10:35:49 CET 2017
From: Alexander Duyck <alexander.h.duyck@xxxxxxxxx>
Date: Fri, 24 Mar 2017 15:01:42 -0700
Subject: i40e: Do not enable NAPI on q_vectors that have no rings
From: Alexander Duyck <alexander.h.duyck@xxxxxxxxx>
[ Upstream commit 13a8cd191a2b470cfd435b3b57dbd21aa65ff78c ]
When testing the epoll w/ busy poll code I found that I could get into a
state where the i40e driver had q_vectors w/ active NAPI that had no rings.
This was resulting in a divide by zero error. To correct it I am updating
the driver code so that we only support NAPI on q_vectors that have 1 or
more rings allocated to them.
Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxx>
Tested-by: Andrew Bowers <andrewx.bowers@xxxxxxxxx>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/intel/i40e/i40e_main.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -4201,8 +4201,12 @@ static void i40e_napi_enable_all(struct
if (!vsi->netdev)
return;
- for (q_idx = 0; q_idx < vsi->num_q_vectors; q_idx++)
- napi_enable(&vsi->q_vectors[q_idx]->napi);
+ for (q_idx = 0; q_idx < vsi->num_q_vectors; q_idx++) {
+ struct i40e_q_vector *q_vector = vsi->q_vectors[q_idx];
+
+ if (q_vector->rx.ring || q_vector->tx.ring)
+ napi_enable(&q_vector->napi);
+ }
}
/**
@@ -4216,8 +4220,12 @@ static void i40e_napi_disable_all(struct
if (!vsi->netdev)
return;
- for (q_idx = 0; q_idx < vsi->num_q_vectors; q_idx++)
- napi_disable(&vsi->q_vectors[q_idx]->napi);
+ for (q_idx = 0; q_idx < vsi->num_q_vectors; q_idx++) {
+ struct i40e_q_vector *q_vector = vsi->q_vectors[q_idx];
+
+ if (q_vector->rx.ring || q_vector->tx.ring)
+ napi_disable(&q_vector->napi);
+ }
}
/**
Patches currently in stable-queue which might be from alexander.h.duyck@xxxxxxxxx are
queue-4.4/i40e-do-not-enable-napi-on-q_vectors-that-have-no-rings.patch
queue-4.4/net-do-not-allow-negative-values-for-busy_read-and-busy_poll-sysctl-interfaces.patch