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References: <20230705114505.63274-1-maxime.coquelin@redhat.com>
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From:   Yongji Xie <xieyongji@bytedance.com>
Date:   Mon, 31 Jul 2023 10:24:47 +0800
Message-ID: <CACycT3tVOKVvhTab7cbjFJsVk3vnWwqyaZ6pGvKmxO8jADj65Q@mail.gmail.com>
Subject: Re: [PATCH] vduse: Use proper spinlock for IRQ injection
To:     Maxime Coquelin <maxime.coquelin@redhat.com>
Cc:     Jason Wang <jasowang@redhat.com>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        David Marchand <david.marchand@redhat.com>,
        Cindy Lu <lulu@redhat.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        virtualization <virtualization@lists.linux-foundation.org>,
        Netdev <netdev@vger.kernel.org>, xuanzhuo@linux.alibaba.com,
        Eugenio Perez Martin <eperezma@redhat.com>
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On Wed, Jul 5, 2023 at 7:45=E2=80=AFPM Maxime Coquelin
<maxime.coquelin@redhat.com> wrote:
>
> The IRQ injection work used spin_lock_irq() to protect the
> scheduling of the softirq, but spin_lock_bh() should be
> used.
>
> With spin_lock_irq(), we noticed delay of more than 6
> seconds between the time a NAPI polling work is scheduled
> and the time it is executed.
>
> Fixes: c8a6153b6c59 ("vduse: Introduce VDUSE - vDPA Device in Userspace")
> Cc: xieyongji@bytedance.com
>
> Suggested-by: Jason Wang <jasowang@redhat.com>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Reviewed-by: Xie Yongji <xieyongji@bytedance.com>

Thanks,
Yongji