From: Yunsheng Lin <[email protected]>
Use napi_consume_skb() to batch consuming skb when cleaning
tx desc in NAPI polling.
Signed-off-by: Yunsheng Lin <[email protected]>
Signed-off-by: Huazhong Tan <[email protected]>
---
drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 27 +++++++++++-----------
drivers/net/ethernet/hisilicon/hns3/hns3_enet.h | 2 +-
drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c | 4 ++--
3 files changed, 17 insertions(+), 16 deletions(-)
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
index 4a49a76..feeaf75 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
@@ -2333,10 +2333,10 @@ static int hns3_alloc_buffer(struct hns3_enet_ring *ring,
}
static void hns3_free_buffer(struct hns3_enet_ring *ring,
- struct hns3_desc_cb *cb)
+ struct hns3_desc_cb *cb, int budget)
{
if (cb->type == DESC_TYPE_SKB)
- dev_kfree_skb_any((struct sk_buff *)cb->priv);
+ napi_consume_skb(cb->priv, budget);
else if (!HNAE3_IS_TX_RING(ring) && cb->pagecnt_bias)
__page_frag_cache_drain(cb->priv, cb->pagecnt_bias);
memset(cb, 0, sizeof(*cb));
@@ -2370,7 +2370,8 @@ static void hns3_buffer_detach(struct hns3_enet_ring *ring, int i)
ring->desc[i].addr = 0;
}
-static void hns3_free_buffer_detach(struct hns3_enet_ring *ring, int i)
+static void hns3_free_buffer_detach(struct hns3_enet_ring *ring, int i,
+ int budget)
{
struct hns3_desc_cb *cb = &ring->desc_cb[i];
@@ -2378,7 +2379,7 @@ static void hns3_free_buffer_detach(struct hns3_enet_ring *ring, int i)
return;
hns3_buffer_detach(ring, i);
- hns3_free_buffer(ring, cb);
+ hns3_free_buffer(ring, cb, budget);
}
static void hns3_free_buffers(struct hns3_enet_ring *ring)
@@ -2386,7 +2387,7 @@ static void hns3_free_buffers(struct hns3_enet_ring *ring)
int i;
for (i = 0; i < ring->desc_num; i++)
- hns3_free_buffer_detach(ring, i);
+ hns3_free_buffer_detach(ring, i, 0);
}
/* free desc along with its attached buffer */
@@ -2431,7 +2432,7 @@ static int hns3_alloc_and_map_buffer(struct hns3_enet_ring *ring,
return 0;
out_with_buf:
- hns3_free_buffer(ring, cb);
+ hns3_free_buffer(ring, cb, 0);
out:
return ret;
}
@@ -2463,7 +2464,7 @@ static int hns3_alloc_ring_buffers(struct hns3_enet_ring *ring)
out_buffer_fail:
for (j = i - 1; j >= 0; j--)
- hns3_free_buffer_detach(ring, j);
+ hns3_free_buffer_detach(ring, j, 0);
return ret;
}
@@ -2491,7 +2492,7 @@ static void hns3_reuse_buffer(struct hns3_enet_ring *ring, int i)
}
static bool hns3_nic_reclaim_desc(struct hns3_enet_ring *ring,
- int *bytes, int *pkts)
+ int *bytes, int *pkts, int budget)
{
/* pair with ring->last_to_use update in hns3_tx_doorbell(),
* smp_store_release() is not used in hns3_tx_doorbell() because
@@ -2514,7 +2515,7 @@ static bool hns3_nic_reclaim_desc(struct hns3_enet_ring *ring,
(*pkts) += (desc_cb->type == DESC_TYPE_SKB);
(*bytes) += desc_cb->length;
/* desc_cb will be cleaned, after hnae3_free_buffer_detach */
- hns3_free_buffer_detach(ring, ntc);
+ hns3_free_buffer_detach(ring, ntc, budget);
if (++ntc == ring->desc_num)
ntc = 0;
@@ -2534,7 +2535,7 @@ static bool hns3_nic_reclaim_desc(struct hns3_enet_ring *ring,
return true;
}
-void hns3_clean_tx_ring(struct hns3_enet_ring *ring)
+void hns3_clean_tx_ring(struct hns3_enet_ring *ring, int budget)
{
struct net_device *netdev = ring_to_netdev(ring);
struct hns3_nic_priv *priv = netdev_priv(netdev);
@@ -2544,7 +2545,7 @@ void hns3_clean_tx_ring(struct hns3_enet_ring *ring)
bytes = 0;
pkts = 0;
- if (unlikely(!hns3_nic_reclaim_desc(ring, &bytes, &pkts)))
+ if (unlikely(!hns3_nic_reclaim_desc(ring, &bytes, &pkts, budget)))
return;
ring->tqp_vector->tx_group.total_bytes += bytes;
@@ -3351,7 +3352,7 @@ static int hns3_nic_common_poll(struct napi_struct *napi, int budget)
* budget and be more aggressive about cleaning up the Tx descriptors.
*/
hns3_for_each_ring(ring, tqp_vector->tx_group)
- hns3_clean_tx_ring(ring);
+ hns3_clean_tx_ring(ring, budget);
/* make sure rx ring budget not smaller than 1 */
if (tqp_vector->num_tqps > 1)
@@ -4195,7 +4196,7 @@ static void hns3_clear_tx_ring(struct hns3_enet_ring *ring)
{
while (ring->next_to_clean != ring->next_to_use) {
ring->desc[ring->next_to_clean].tx.bdtp_fe_sc_vld_ra_ri = 0;
- hns3_free_buffer_detach(ring, ring->next_to_clean);
+ hns3_free_buffer_detach(ring, ring->next_to_clean, 0);
ring_ptr_move_fw(ring, next_to_clean);
}
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
index 20e62ce..8a6c8ba 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
@@ -576,7 +576,7 @@ void hns3_ethtool_set_ops(struct net_device *netdev);
int hns3_set_channels(struct net_device *netdev,
struct ethtool_channels *ch);
-void hns3_clean_tx_ring(struct hns3_enet_ring *ring);
+void hns3_clean_tx_ring(struct hns3_enet_ring *ring, int budget);
int hns3_init_all_ring(struct hns3_nic_priv *priv);
int hns3_uninit_all_ring(struct hns3_nic_priv *priv);
int hns3_nic_reset_all_ring(struct hnae3_handle *h);
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c b/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c
index f402c39..afa1656 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c
@@ -223,14 +223,14 @@ static u32 hns3_lb_check_rx_ring(struct hns3_nic_priv *priv, u32 budget)
}
static void hns3_lb_clear_tx_ring(struct hns3_nic_priv *priv, u32 start_ringid,
- u32 end_ringid, u32 budget)
+ u32 end_ringid, int budget)
{
u32 i;
for (i = start_ringid; i <= end_ringid; i++) {
struct hns3_enet_ring *ring = &priv->ring[i];
- hns3_clean_tx_ring(ring);
+ hns3_clean_tx_ring(ring, budget);
}
}
--
2.7.4
On Mon, 2020-09-14 at 20:06 +0800, Huazhong Tan wrote:
> From: Yunsheng Lin <[email protected]>
>
> Use napi_consume_skb() to batch consuming skb when cleaning
> tx desc in NAPI polling.
>
> Signed-off-by: Yunsheng Lin <[email protected]>
> Signed-off-by: Huazhong Tan <[email protected]>
> ---
> drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 27 +++++++++++-
> ----------
> drivers/net/ethernet/hisilicon/hns3/hns3_enet.h | 2 +-
> drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c | 4 ++--
> 3 files changed, 17 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
> b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
> index 4a49a76..feeaf75 100644
> --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
> +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
> @@ -2333,10 +2333,10 @@ static int hns3_alloc_buffer(struct
> hns3_enet_ring *ring,
> }
>
> static void hns3_free_buffer(struct hns3_enet_ring *ring,
> - struct hns3_desc_cb *cb)
> + struct hns3_desc_cb *cb, int budget)
> {
> if (cb->type == DESC_TYPE_SKB)
> - dev_kfree_skb_any((struct sk_buff *)cb->priv);
> + napi_consume_skb(cb->priv, budget);
This code can be reached from hns3_lb_clear_tx_ring() below which is
your loopback test and called with non-zero budget, I am not sure you
are allowed to call napi_consume_skb() with non-zero budget outside
napi context, perhaps the cb->type for loopback test is different in lb
test case ? Idk.. , please double check other code paths.
[...]
> static void hns3_lb_clear_tx_ring(struct hns3_nic_priv *priv, u32
> start_ringid,
> - u32 end_ringid, u32 budget)
> + u32 end_ringid, int budget)
> {
> u32 i;
>
> for (i = start_ringid; i <= end_ringid; i++) {
> struct hns3_enet_ring *ring = &priv->ring[i];
>
> - hns3_clean_tx_ring(ring);
> + hns3_clean_tx_ring(ring, budget);
> }
> }
>
On 2020/9/15 13:09, Saeed Mahameed wrote:
> On Mon, 2020-09-14 at 20:06 +0800, Huazhong Tan wrote:
>> From: Yunsheng Lin <[email protected]>
>>
>> Use napi_consume_skb() to batch consuming skb when cleaning
>> tx desc in NAPI polling.
>>
>> Signed-off-by: Yunsheng Lin <[email protected]>
>> Signed-off-by: Huazhong Tan <[email protected]>
>> ---
>> drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 27 +++++++++++-
>> ----------
>> drivers/net/ethernet/hisilicon/hns3/hns3_enet.h | 2 +-
>> drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c | 4 ++--
>> 3 files changed, 17 insertions(+), 16 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
>> b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
>> index 4a49a76..feeaf75 100644
>> --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
>> +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
>> @@ -2333,10 +2333,10 @@ static int hns3_alloc_buffer(struct
>> hns3_enet_ring *ring,
>> }
>>
>> static void hns3_free_buffer(struct hns3_enet_ring *ring,
>> - struct hns3_desc_cb *cb)
>> + struct hns3_desc_cb *cb, int budget)
>> {
>> if (cb->type == DESC_TYPE_SKB)
>> - dev_kfree_skb_any((struct sk_buff *)cb->priv);
>> + napi_consume_skb(cb->priv, budget);
>
> This code can be reached from hns3_lb_clear_tx_ring() below which is
> your loopback test and called with non-zero budget, I am not sure you
> are allowed to call napi_consume_skb() with non-zero budget outside
> napi context, perhaps the cb->type for loopback test is different in lb
> test case ? Idk.. , please double check other code paths.
Yes, loopback test may call napi_consume_skb() with non-zero budget outside
napi context. Thanks for pointing out this case.
How about add the below WARN_ONCE() in napi_consume_skb() to catch this
kind of error?
WARN_ONCE(!in_serving_softirq(), "napi_consume_skb() is called with non-zero budget outside napi context");
>
> [...]
>
>> static void hns3_lb_clear_tx_ring(struct hns3_nic_priv *priv, u32
>> start_ringid,
>> - u32 end_ringid, u32 budget)
>> + u32 end_ringid, int budget)
>> {
>> u32 i;
>>
>> for (i = start_ringid; i <= end_ringid; i++) {
>> struct hns3_enet_ring *ring = &priv->ring[i];
>>
>> - hns3_clean_tx_ring(ring);
>> + hns3_clean_tx_ring(ring, budget);
>> }
>> }
>>
On Tue, 2020-09-15 at 15:04 +0800, Yunsheng Lin wrote:
> On 2020/9/15 13:09, Saeed Mahameed wrote:
> > On Mon, 2020-09-14 at 20:06 +0800, Huazhong Tan wrote:
> > > From: Yunsheng Lin <[email protected]>
> > >
> > > Use napi_consume_skb() to batch consuming skb when cleaning
> > > tx desc in NAPI polling.
> > >
> > > Signed-off-by: Yunsheng Lin <[email protected]>
> > > Signed-off-by: Huazhong Tan <[email protected]>
> > > ---
> > > drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 27
> > > +++++++++++-
> > > ----------
> > > drivers/net/ethernet/hisilicon/hns3/hns3_enet.h | 2 +-
> > > drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c | 4 ++--
> > > 3 files changed, 17 insertions(+), 16 deletions(-)
> > >
> > > diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
> > > b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
> > > index 4a49a76..feeaf75 100644
> > > --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
> > > +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
> > > @@ -2333,10 +2333,10 @@ static int hns3_alloc_buffer(struct
> > > hns3_enet_ring *ring,
> > > }
> > >
> > > static void hns3_free_buffer(struct hns3_enet_ring *ring,
> > > - struct hns3_desc_cb *cb)
> > > + struct hns3_desc_cb *cb, int budget)
> > > {
> > > if (cb->type == DESC_TYPE_SKB)
> > > - dev_kfree_skb_any((struct sk_buff *)cb->priv);
> > > + napi_consume_skb(cb->priv, budget);
> >
> > This code can be reached from hns3_lb_clear_tx_ring() below which
> > is
> > your loopback test and called with non-zero budget, I am not sure
> > you
> > are allowed to call napi_consume_skb() with non-zero budget outside
> > napi context, perhaps the cb->type for loopback test is different
> > in lb
> > test case ? Idk.. , please double check other code paths.
>
> Yes, loopback test may call napi_consume_skb() with non-zero budget
> outside
> napi context. Thanks for pointing out this case.
>
> How about add the below WARN_ONCE() in napi_consume_skb() to catch
> this
> kind of error?
>
> WARN_ONCE(!in_serving_softirq(), "napi_consume_skb() is called with
> non-zero budget outside napi context");
>
Cc: Eric
I don't know, need to check performance impact.
And in_serving_softirq() doesn't necessarily mean in napi
but looking at _kfree_skb_defer(), i think it shouldn't care if napi or
not as long as it runs in soft irq it will push the skb to that
particular cpu napi_alloc_cache, which should be fine.
Maybe instead of the WARN_ONCE just remove the budget condition and
replace it with
if (!in_serving_softirq())
dev_consume_skb_any(skb);
On Wed, Sep 16, 2020 at 10:33 AM Saeed Mahameed <[email protected]> wrote:
>
> On Tue, 2020-09-15 at 15:04 +0800, Yunsheng Lin wrote:
> > On 2020/9/15 13:09, Saeed Mahameed wrote:
> > > On Mon, 2020-09-14 at 20:06 +0800, Huazhong Tan wrote:
> > > > From: Yunsheng Lin <[email protected]>
> > > >
> > > > Use napi_consume_skb() to batch consuming skb when cleaning
> > > > tx desc in NAPI polling.
> > > >
> > > > Signed-off-by: Yunsheng Lin <[email protected]>
> > > > Signed-off-by: Huazhong Tan <[email protected]>
> > > > ---
> > > > drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 27
> > > > +++++++++++-
> > > > ----------
> > > > drivers/net/ethernet/hisilicon/hns3/hns3_enet.h | 2 +-
> > > > drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c | 4 ++--
> > > > 3 files changed, 17 insertions(+), 16 deletions(-)
> > > >
> > > > diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
> > > > b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
> > > > index 4a49a76..feeaf75 100644
> > > > --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
> > > > +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
> > > > @@ -2333,10 +2333,10 @@ static int hns3_alloc_buffer(struct
> > > > hns3_enet_ring *ring,
> > > > }
> > > >
> > > > static void hns3_free_buffer(struct hns3_enet_ring *ring,
> > > > - struct hns3_desc_cb *cb)
> > > > + struct hns3_desc_cb *cb, int budget)
> > > > {
> > > > if (cb->type == DESC_TYPE_SKB)
> > > > - dev_kfree_skb_any((struct sk_buff *)cb->priv);
> > > > + napi_consume_skb(cb->priv, budget);
> > >
> > > This code can be reached from hns3_lb_clear_tx_ring() below which
> > > is
> > > your loopback test and called with non-zero budget, I am not sure
> > > you
> > > are allowed to call napi_consume_skb() with non-zero budget outside
> > > napi context, perhaps the cb->type for loopback test is different
> > > in lb
> > > test case ? Idk.. , please double check other code paths.
> >
> > Yes, loopback test may call napi_consume_skb() with non-zero budget
> > outside
> > napi context. Thanks for pointing out this case.
> >
> > How about add the below WARN_ONCE() in napi_consume_skb() to catch
> > this
> > kind of error?
> >
> > WARN_ONCE(!in_serving_softirq(), "napi_consume_skb() is called with
> > non-zero budget outside napi context");
> >
>
> Cc: Eric
>
> I don't know, need to check performance impact.
> And in_serving_softirq() doesn't necessarily mean in napi
> but looking at _kfree_skb_defer(), i think it shouldn't care if napi or
> not as long as it runs in soft irq it will push the skb to that
> particular cpu napi_alloc_cache, which should be fine.
>
> Maybe instead of the WARN_ONCE just remove the budget condition and
> replace it with
>
> if (!in_serving_softirq())
> dev_consume_skb_any(skb);
>
I think we need to keep costs small.
So lets add a CONFIG_DEBUG_NET option so that developers can add
various DEBUG_NET() clauses.
On 2020/9/16 16:38, Eric Dumazet wrote:
> On Wed, Sep 16, 2020 at 10:33 AM Saeed Mahameed <[email protected]> wrote:
>>
>> On Tue, 2020-09-15 at 15:04 +0800, Yunsheng Lin wrote:
>>> On 2020/9/15 13:09, Saeed Mahameed wrote:
>>>> On Mon, 2020-09-14 at 20:06 +0800, Huazhong Tan wrote:
>>>>> From: Yunsheng Lin <[email protected]>
>>>>>
>>>>> Use napi_consume_skb() to batch consuming skb when cleaning
>>>>> tx desc in NAPI polling.
>>>>>
>>>>> Signed-off-by: Yunsheng Lin <[email protected]>
>>>>> Signed-off-by: Huazhong Tan <[email protected]>
>>>>> ---
>>>>> drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 27
>>>>> +++++++++++-
>>>>> ----------
>>>>> drivers/net/ethernet/hisilicon/hns3/hns3_enet.h | 2 +-
>>>>> drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c | 4 ++--
>>>>> 3 files changed, 17 insertions(+), 16 deletions(-)
>>>>>
>>>>> diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
>>>>> b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
>>>>> index 4a49a76..feeaf75 100644
>>>>> --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
>>>>> +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
>>>>> @@ -2333,10 +2333,10 @@ static int hns3_alloc_buffer(struct
>>>>> hns3_enet_ring *ring,
>>>>> }
>>>>>
>>>>> static void hns3_free_buffer(struct hns3_enet_ring *ring,
>>>>> - struct hns3_desc_cb *cb)
>>>>> + struct hns3_desc_cb *cb, int budget)
>>>>> {
>>>>> if (cb->type == DESC_TYPE_SKB)
>>>>> - dev_kfree_skb_any((struct sk_buff *)cb->priv);
>>>>> + napi_consume_skb(cb->priv, budget);
>>>>
>>>> This code can be reached from hns3_lb_clear_tx_ring() below which
>>>> is
>>>> your loopback test and called with non-zero budget, I am not sure
>>>> you
>>>> are allowed to call napi_consume_skb() with non-zero budget outside
>>>> napi context, perhaps the cb->type for loopback test is different
>>>> in lb
>>>> test case ? Idk.. , please double check other code paths.
>>>
>>> Yes, loopback test may call napi_consume_skb() with non-zero budget
>>> outside
>>> napi context. Thanks for pointing out this case.
>>>
>>> How about add the below WARN_ONCE() in napi_consume_skb() to catch
>>> this
>>> kind of error?
>>>
>>> WARN_ONCE(!in_serving_softirq(), "napi_consume_skb() is called with
>>> non-zero budget outside napi context");
>>>
>>
>> Cc: Eric
>>
>> I don't know, need to check performance impact.
>> And in_serving_softirq() doesn't necessarily mean in napi
>> but looking at _kfree_skb_defer(), i think it shouldn't care if napi or
>> not as long as it runs in soft irq it will push the skb to that
>> particular cpu napi_alloc_cache, which should be fine.
Yes, we only need to ensure _kfree_skb_defer() runs with automic context.
And it seems NAPI polling can be in thread context with BH disabled in below
patch, so in_softirq() checking should be more future-proof?
* in_softirq() - We have BH disabled, or are processing softirqs
net: add support for threaded NAPI polling
https://www.mail-archive.com/[email protected]/msg348491.html
>>
>> Maybe instead of the WARN_ONCE just remove the budget condition and
>> replace it with
>>
>> if (!in_serving_softirq())
>> dev_consume_skb_any(skb);
Yes, that is good idea, _kfree_skb_defer() is only called in softirq or
BH disabled context, dev_consume_skb_any(skb) is called in other context,
so driver author do not need to worry about the calling context of the
napi_consume_skb().
>>
>
> I think we need to keep costs small.
>
> So lets add a CONFIG_DEBUG_NET option so that developers can add
> various DEBUG_NET() clauses.
Do you means something like below:
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 157e024..61a6a62 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -5104,6 +5104,15 @@ do { \
})
#endif
+#if defined(CONFIG_DEBUG_NET)
+#define DEBUG_NET_WARN(condition, format...) \
+ do { \
+ WARN(condition, ##__VA_ARGS__);
+ } while (0)
+#else
+#define DEBUG_NET_WARN(condition, format...)
+#endif
+
/*
* The list of packet types we will receive (as opposed to discard)
* and the routines to invoke.
diff --git a/net/Kconfig b/net/Kconfig
index 3831206..f59ea4b 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -473,3 +473,9 @@ config HAVE_CBPF_JIT
# Extended BPF JIT (eBPF)
config HAVE_EBPF_JIT
bool
+
+config DEBUG_NET
+ bool
+ depends on DEBUG_KERNEL
+ help
+ Say Y here to add some extra checks and diagnostics to networking.
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index bfd7483..10547db 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -904,6 +904,9 @@ void napi_consume_skb(struct sk_buff *skb, int budget)
return;
}
+ DEBUG_NET_WARN(!in_serving_softirq(),
+ "napi_consume_skb() is called with non-zero budget outside softirq context");
+
if (!skb_unref(skb))
return;
> .
>