From: Jesse Brandeburg jesse.brandeburg@intel.com
[ Upstream commit eaeace60778e524a2820d0c0ad60bf80289e292c ]
Oleksandr brought a bug report where netpoll causes trace messages in the log on igb.
Danielle brought this back up as still occurring, so we'll try again.
[22038.710800] ------------[ cut here ]------------ [22038.710801] igb_poll+0x0/0x1440 [igb] exceeded budget in poll [22038.710802] WARNING: CPU: 12 PID: 40362 at net/core/netpoll.c:155 netpoll_poll_dev+0x18a/0x1a0
As Alex suggested, change the driver to return work_done at the exit of napi_poll, which should be safe to do in this driver because it is not polling multiple queues in this single napi context (multiple queues attached to one MSI-X vector). Several other drivers contain the same simple sequence, so I hope this will not create new problems.
Fixes: 16eb8815c235 ("igb: Refactor clean_rx_irq to reduce overhead and improve performance") Reported-by: Oleksandr Natalenko oleksandr@natalenko.name Reported-by: Danielle Ratson danieller@nvidia.com Suggested-by: Alexander Duyck alexander.duyck@gmail.com Signed-off-by: Jesse Brandeburg jesse.brandeburg@intel.com Tested-by: Oleksandr Natalenko oleksandr@natalenko.name Tested-by: Danielle Ratson danieller@nvidia.com Link: https://lore.kernel.org/r/20211123204000.1597971-1-jesse.brandeburg@intel.co... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/intel/igb/igb_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index e24fb122c03a2..d5432d1448c05 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -8032,7 +8032,7 @@ static int igb_poll(struct napi_struct *napi, int budget) if (likely(napi_complete_done(napi, work_done))) igb_ring_irq_enable(q_vector);
- return min(work_done, budget - 1); + return work_done; }
/**