Jason Wang
2020-Sep-09 09:04 UTC
[PATCH] vhost_vdpa: remove unnecessary spin_lock in vhost_vring_call
On 2020/9/9 ??2:52, Zhu Lingshan wrote:> This commit removed unnecessary spin_locks in vhost_vring_call > and related operations. Because we manipulate irq offloading > contents in vhost_vdpa ioctl code path which is already > protected by dev mutex and vq mutex. > > Signed-off-by: Zhu Lingshan <lingshan.zhu at intel.com>Acked-by: Jason Wang <jasowang at redhat.com>> --- > drivers/vhost/vdpa.c | 8 +------- > drivers/vhost/vhost.c | 3 --- > drivers/vhost/vhost.h | 1 - > 3 files changed, 1 insertion(+), 11 deletions(-) > > diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c > index 3fab94f88894..bc679d0b7b87 100644 > --- a/drivers/vhost/vdpa.c > +++ b/drivers/vhost/vdpa.c > @@ -97,26 +97,20 @@ static void vhost_vdpa_setup_vq_irq(struct vhost_vdpa *v, u16 qid) > return; > > irq = ops->get_vq_irq(vdpa, qid); > - spin_lock(&vq->call_ctx.ctx_lock); > irq_bypass_unregister_producer(&vq->call_ctx.producer); > - if (!vq->call_ctx.ctx || irq < 0) { > - spin_unlock(&vq->call_ctx.ctx_lock); > + if (!vq->call_ctx.ctx || irq < 0) > return; > - } > > vq->call_ctx.producer.token = vq->call_ctx.ctx; > vq->call_ctx.producer.irq = irq; > ret = irq_bypass_register_producer(&vq->call_ctx.producer); > - spin_unlock(&vq->call_ctx.ctx_lock); > } > > static void vhost_vdpa_unsetup_vq_irq(struct vhost_vdpa *v, u16 qid) > { > struct vhost_virtqueue *vq = &v->vqs[qid]; > > - spin_lock(&vq->call_ctx.ctx_lock); > irq_bypass_unregister_producer(&vq->call_ctx.producer); > - spin_unlock(&vq->call_ctx.ctx_lock); > } > > static void vhost_vdpa_reset(struct vhost_vdpa *v) > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index b45519ca66a7..99f27ce982da 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -302,7 +302,6 @@ static void vhost_vring_call_reset(struct vhost_vring_call *call_ctx) > { > call_ctx->ctx = NULL; > memset(&call_ctx->producer, 0x0, sizeof(struct irq_bypass_producer)); > - spin_lock_init(&call_ctx->ctx_lock); > } > > static void vhost_vq_reset(struct vhost_dev *dev, > @@ -1637,9 +1636,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg > break; > } > > - spin_lock(&vq->call_ctx.ctx_lock); > swap(ctx, vq->call_ctx.ctx); > - spin_unlock(&vq->call_ctx.ctx_lock); > break; > case VHOST_SET_VRING_ERR: > if (copy_from_user(&f, argp, sizeof f)) { > diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h > index 9032d3c2a9f4..486dcf371e06 100644 > --- a/drivers/vhost/vhost.h > +++ b/drivers/vhost/vhost.h > @@ -64,7 +64,6 @@ enum vhost_uaddr_type { > struct vhost_vring_call { > struct eventfd_ctx *ctx; > struct irq_bypass_producer producer; > - spinlock_t ctx_lock; > }; > > /* The virtqueue structure describes a queue attached to a device. */