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From: Jakub Kicinski <kuba@kernel.org>
To: "Michael S. Tsirkin" <mst@redhat.com>, Jason Wang <jasowang@redhat.com>
Cc: Wei Wang <weiwan@google.com>, David Miller <davem@davemloft.net>,
	netdev@vger.kernel.org, Willem de Bruijn <willemb@google.com>,
	virtualization@lists.linux-foundation.org
Subject: Re: [PATCH net] virtio-net: suppress bad irq warning for tx napi
Date: Mon, 1 Feb 2021 18:24:04 -0800	[thread overview]
Message-ID: <20210201182404.4ac54542@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> (raw)
In-Reply-To: <20210129002136.70865-1-weiwan@google.com>

On Thu, 28 Jan 2021 16:21:36 -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 adds a new param to struct vring_virtqueue, and we set it for
> tx virtqueues if napi-tx is enabled, to suppress the warning in such
> case.
> 
> Fixes: 7b0411ef4aa6 ("virtio-net: clean tx descriptors from rx napi")
> Reported-by: Rick Jones <jonesrick@google.com>
> Signed-off-by: Wei Wang <weiwan@google.com>
> Signed-off-by: Willem de Bruijn <willemb@google.com>

Michael, Jason, does this one look okay to you?

  reply	other threads:[~2021-02-02  2:24 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-29  0:21 [PATCH net] virtio-net: suppress bad irq warning for tx napi Wei Wang
2021-02-02  2:24 ` Jakub Kicinski [this message]
2021-02-02  3:06 ` Jason Wang
2021-02-02 14:37   ` Willem de Bruijn
2021-02-03  5:33     ` Jason Wang
2021-02-03 18:28       ` Willem de Bruijn
2021-02-04  3:06         ` Jason Wang
2021-02-04 20:50           ` Willem de Bruijn
2021-02-08  3:29             ` Jason Wang
2021-02-08 19:08               ` Willem de Bruijn
2021-02-09  3:27                 ` Jason Wang
2021-02-09 14:58                   ` Willem de Bruijn
2021-02-09 18:00                     ` Wei Wang
2021-02-10  9:14                       ` Michael S. Tsirkin
2021-02-11  0:13                         ` Wei Wang
2021-02-18  5:39                         ` Jason Wang
2021-02-21 11:33                           ` Michael S. Tsirkin
2021-02-02 23:11 ` Michael S. Tsirkin
2021-02-02 23:47   ` Wei Wang
2021-02-02 23:53     ` Willem de Bruijn
2021-02-03  0:06       ` Willem de Bruijn
2021-02-03 10:38         ` Michael S. Tsirkin
2021-02-03 18:24           ` Willem de Bruijn
2021-02-03 23:09             ` Michael S. Tsirkin
2021-02-03 23:52               ` Wei Wang
2021-02-04 20:47                 ` Willem de Bruijn
2021-02-05 22:28                   ` Wei Wang
2021-04-13  5:15                     ` Michael S. Tsirkin
2021-09-29 20:21                       ` Wei Wang
2021-09-29 21:53                         ` Michael S. Tsirkin
2021-09-29 23:08                           ` Wei Wang
2021-09-30  5:40                             ` Michael S. Tsirkin
2021-09-30 18:10                             ` Dave Taht
2021-04-12 22:08 ` Michael S. Tsirkin
2021-04-12 22:33   ` Michael S. Tsirkin
2021-04-12 23:14     ` David Miller
2021-04-13  4:24       ` Michael S. Tsirkin

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