From: Jonathan Lemon <b...@fb.com> netcons will call napi_poll with a budget of 0, indicating a non-napi caller (and also called with irqs disabled). Call free_old_xmit_skbs() with the is_napi parameter set correctly.
Found by this splat: WARNING: CPU: 2 PID: 1368 at net/core/skbuff.c:650 skb_release_head_state+0x7f/0x90 RIP: 0010:skb_release_head_state+0x7f/0x90 Code: e7 7f 08 00 80 7b 7f 00 74 f3 48 8b bb d8 00 00 00 5b e9 d4 f2 ff ff 48 83 e7 fe e8 bb f5 01 00 RSP: 0000:ffffc900000e4d18 EFLAGS: 00010006 RAX: ffffffff818fc470 RBX: ffff888235a36d00 RCX: ffff88822df23000 RDX: 0000000000010000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff888235a36d00 R08: 0000000000000002 R09: 00000000ffffdd86 R10: 00000000ffffdd86 R11: 0000000000000000 R12: ffff8882367b4800 R13: 0000000000000001 R14: ffff8882367b4ac8 R15: ffff8882367b4ab8 FS: 00007fdc30f8a700(0000) GS:ffff888237d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdc300ea000 CR3: 000000022992f001 CR4: 0000000000360ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> skb_release_all+0xe/0x30 napi_consume_skb+0x4c/0x110 free_old_xmit_skbs+0x3e/0xa0 [virtio_net] virtnet_poll_tx+0x7e/0xe0 [virtio_net] netpoll_poll_dev+0xba/0x190 netpoll_send_skb_on_dev+0x1e7/0x240 netpoll_send_udp+0x2b3/0x3d0 write_ext_msg+0x1be/0x1d0 console_unlock+0x227/0x4b0 vprintk_emit+0xe5/0x1b0 printk+0x58/0x6f smp_apic_timer_interrupt+0x5e/0x120 apic_timer_interrupt+0xf/0x20 </IRQ> Signed-off-by: Jonathan Lemon <jonathan.le...@gmail.com> --- drivers/net/virtio_net.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 21b71148c532..59f65ac9e4c7 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1518,7 +1518,7 @@ static int virtnet_poll_tx(struct napi_struct *napi, int budget) txq = netdev_get_tx_queue(vi->dev, index); __netif_tx_lock(txq, raw_smp_processor_id()); - free_old_xmit_skbs(sq, true); + free_old_xmit_skbs(sq, budget != 0); __netif_tx_unlock(txq); virtqueue_napi_complete(napi, sq->vq, 0); -- 2.24.1