On Fri, Feb 19, 2021 at 05:44:34PM -0800, Wei Wang wrote: > With the implementation of napi-tx in virtio driver, we clean tx > descriptors from rx napi handler, for the purpose of reducing tx > complete interrupts. But this could introduce a race where tx complete > interrupt has been raised, but the handler found there is no work to do > because we have done the work in the previous rx interrupt handler. > This could lead to the following warning msg: > [ 3588.010778] irq 38: nobody cared (try booting with the > "irqpoll" option) > [ 3588.017938] CPU: 4 PID: 0 Comm: swapper/4 Not tainted > 5.3.0-19-generic #20~18.04.2-Ubuntu > [ 3588.017940] Call Trace: > [ 3588.017942] <IRQ> > [ 3588.017951] dump_stack+0x63/0x85 > [ 3588.017953] __report_bad_irq+0x35/0xc0 > [ 3588.017955] note_interrupt+0x24b/0x2a0 > [ 3588.017956] handle_irq_event_percpu+0x54/0x80 > [ 3588.017957] handle_irq_event+0x3b/0x60 > [ 3588.017958] handle_edge_irq+0x83/0x1a0 > [ 3588.017961] handle_irq+0x20/0x30 > [ 3588.017964] do_IRQ+0x50/0xe0 > [ 3588.017966] common_interrupt+0xf/0xf > [ 3588.017966] </IRQ> > [ 3588.017989] handlers: > [ 3588.020374] [<000000001b9f1da8>] vring_interrupt > [ 3588.025099] Disabling IRQ #38 > > This patch series contains 2 patches. The first one adds a new param to > struct vring_virtqueue to control if we want to suppress the bad irq > warning. And the second patch in virtio-net sets it for tx virtqueues if > napi-tx is enabled. I'm going to be busy until March, I think there should be a better way to fix this though. Will think about it and respond in about a week. > Wei Wang (2): > virtio: add a new parameter in struct virtqueue > virtio-net: suppress bad irq warning for tx napi > > drivers/net/virtio_net.c | 19 ++++++++++++++----- > drivers/virtio/virtio_ring.c | 16 ++++++++++++++++ > include/linux/virtio.h | 2 ++ > 3 files changed, 32 insertions(+), 5 deletions(-) > > -- > 2.30.0.617.g56c4b15f3c-goog _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
