This is a note to let you know that I've just added the patch titled vduse: Use proper spinlock for IRQ injection to the 6.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: vduse-use-proper-spinlock-for-irq-injection.patch and it can be found in the queue-6.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 6f4ab4dfa86e69a9ff9f98faa78c4858efdc2fa1 Author: Maxime Coquelin <maxime.coquelin@xxxxxxxxxx> Date: Wed Jul 5 13:45:05 2023 +0200 vduse: Use proper spinlock for IRQ injection [ Upstream commit 7ca26efb09a1543fddb29308ea3b63b66cb5d3ee ] 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@xxxxxxxxxxxxx Suggested-by: Jason Wang <jasowang@xxxxxxxxxx> Signed-off-by: Maxime Coquelin <maxime.coquelin@xxxxxxxxxx> Message-Id: <20230705114505.63274-1-maxime.coquelin@xxxxxxxxxx> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Acked-by: Jason Wang <jasowang@xxxxxxxxxx> Reviewed-by: Xie Yongji <xieyongji@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c index 0d84e6a9c3cca..76d4ab451f599 100644 --- a/drivers/vdpa/vdpa_user/vduse_dev.c +++ b/drivers/vdpa/vdpa_user/vduse_dev.c @@ -935,10 +935,10 @@ static void vduse_dev_irq_inject(struct work_struct *work) { struct vduse_dev *dev = container_of(work, struct vduse_dev, inject); - spin_lock_irq(&dev->irq_lock); + spin_lock_bh(&dev->irq_lock); if (dev->config_cb.callback) dev->config_cb.callback(dev->config_cb.private); - spin_unlock_irq(&dev->irq_lock); + spin_unlock_bh(&dev->irq_lock); } static void vduse_vq_irq_inject(struct work_struct *work) @@ -946,10 +946,10 @@ static void vduse_vq_irq_inject(struct work_struct *work) struct vduse_virtqueue *vq = container_of(work, struct vduse_virtqueue, inject); - spin_lock_irq(&vq->irq_lock); + spin_lock_bh(&vq->irq_lock); if (vq->ready && vq->cb.callback) vq->cb.callback(vq->cb.private); - spin_unlock_irq(&vq->irq_lock); + spin_unlock_bh(&vq->irq_lock); } static bool vduse_vq_signal_irqfd(struct vduse_virtqueue *vq)