On Wed, Feb 12, 2025 at 7:34 PM Breno Leitao leitao@debian.org wrote:
The netdevsim driver was getting NOHZ tick-stop errors during packet transmission due to pending softirq work when calling napi_schedule().
This is showing the following message when running netconsole selftest.
NOHZ tick-stop error: local softirq work is pending, handler #08!!!Add local_bh_disable()/enable() around the napi_schedule() call to prevent softirqs from being handled during this xmit.
Cc: stable@vger.kernel.org Fixes: 3762ec05a9fb ("netdevsim: add NAPI support") Suggested-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Breno Leitao leitao@debian.org
drivers/net/netdevsim/netdev.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c index 42f247cbdceecbadf27f7090c030aa5bd240c18a..6aeb081b06da226ab91c49f53d08f465570877ae 100644 --- a/drivers/net/netdevsim/netdev.c +++ b/drivers/net/netdevsim/netdev.c @@ -87,7 +87,9 @@ static netdev_tx_t nsim_start_xmit(struct sk_buff *skb, struct net_device *dev) if (unlikely(nsim_forward_skb(peer_dev, skb, rq) == NET_RX_DROP)) goto out_drop_cnt;
local_bh_disable(); napi_schedule(&rq->napi);local_bh_enable();
I thought all ndo_start_xmit() were done under local_bh_disable()
Could you give more details ?